CA1336498C - Pharmaceutical formulations for parenteral use - Google Patents

Abstract

Aqueous parenteral solutions of drugs which are insoluble or only sparingly soluble in water and/or which are unstable in water, combined with a hydroxy-propyl, hydroxyethyl, glucosyl, maltosyl or maltotrio-syl derivative of B- or .gamma.-cyclodextrin, provide a means for alleviating problems associated with drug precipi-tation at the injection site and/or in the lungs or other organs following parenteral administration.

Description

PH~R~ACEUTICAL FOR~UL~rIO~S
FOR P~E~TER~L USE

FIELn OF THE INVENrION:

The present invention relates to aqueous parenteral solutions of drugs which are insoluble or only sparingly soluble in water and/or which are unstable in water, combined with selected cyclodex-trins. The solutions provide a means for alleviating Droblems associated with drug precipitation at the injection site and/or in the lungs or other organs following parenteral administration.

BACKGROUN~ OF THE INVENTION:

Cyclodextrins are cyclic oligosaccharides. The most common cyclodextrins are ~-cyclodextrin, which is composed of a ring of six glucose residues, B-CYC10-dextrin, which is composed of a ring of seven glucose residues, and r-cYclodextrin, which is composed of a ring of eight glucose units. rhe inside cavity of a cyclodextrin is lipophilic, while the outside of the cyclodextrin is hydrophilic: this combination of properties has led to widespread study of the natural cyclodextrins, particularly in connection with phar-maceuticals, and many inclusion complexes have been reported. B-Cyclodextrin has been of special interest because of its cavity size, but its relatively low aqueous solubility has limited its use in the pharmaceutical field.

~ ttempts to modify the propert~es of the natural cyclodextrins have resulted in the development of heptakis (2,6-di-0-methyl)-B-cyclodextrin, heptakis (2,3,6-tri-0-methyl)-g-cyclodextrin, hydroxypropyl-~-cyclodextrin, B-cyclodextrin-epichlorohydrin polymer and others. For a comprehensive review of cyclo-dextr1ns an~ their use in pharmaceutical research, see Pitha et al, in Controlled nrug Delivery, ed. S.D.
~ruck, Vol. I, CRC Press, Boca Raton, Florida, pp. 125-148 (1983). For an even more recent overview, see Uekama et al, in CRC Critical Reviews in Therapeutic Drug Carrier Systems, Vol. 3 (1), 1-40 (1987); Uekama, in Topics in Pharmaceutical Sciences 1987, eds. D.D.
Breimer and P. Speiser, Elsevier Science Publishers B.V. (Biomedical Division), 1987, 181-194; and Pagington, Chemistry in Britain, May 1987, pp. 455-458.
Inclusion complexes of a-, B- or y-cyclodextrin or their mixtures with a variety of drugs have been de-scribed by numerous parties and various advantages havebeen attributed to the complexes. These descriptions include the following:

1 33~498 U S ACTIVE
Ih-cnluRPA~E~T ~0 I~6REDIE~r USE ADVAnTA6' Noda et l 4.02~.223 menthol b/or nt1phlog1st1c. reduced unple sant methyl analges1c odor. 1ncreased sal1cylate ~et pac~1ng effect Sze~tl1 et al 4.228.160 lndoveth-c1n ant1-1nflam- reduced ulcer-t1ve ~atory. pro- effect tect1ve dur1ng prcg Ha~-sh1 et al 4.232.009 _halo-PGI2 h~pD~s1ve. 1ncreased stab111t~
an~logs uter1ne con-tractton st1mulat1ng, blood platelet agg-ey~t10n 1nhtb1ttng ~atsumoto et al 4,351,846 3-hydroxy- and uter1ne contrac- increased stab11ity 3-oxo- t10n st1mulat1ng prostagland1n analogs ramah1ra et al 4.352.793 bencyclane ant1convulsant, 1ncreased stab111ty fumarate vasodtlat1ve at strong ac1d pH, faster gastrtc e~pty1ng, h1gher blood concentrations, less 1rr1tat10n, 1mproved hemolyt1c act1v1ty L1par1 4,383.992 stero1ds-- hormonal 1mproved ~ater cort1costero1ds, solub111t~, 1ncreased ar1ro3~ns. tke; ~- ~1c response anabol1c 1n eye stero1ds, estrogens, proges~agens ~1colau 4,~0~,795 p-hexadecyl- ant1athero- ~nha~ced am1noben201c sclerot1c b10ava11ab111ty ac1d sod1um s~lt ~.S. ~Iff lliYE~O~Q~ MO. I~IEIIT USE ADYAJ~AI;E
Tuttlel4.U4,209 3.4-d11sobutyr- card1ac ylox~-~-t3-(4- contract111ty 1sobut~r~10x~- agent phen~l)-l-meth~l-n-prop~l]-e-phenethylan~ne Tuttle 4.425.336 3.4-d1h~droxy- card1ac capable of oral H-[3-(4-h~drox~- contract111t~ adm1n1strat10n phen~l)-l- agent methyl-n-propyl]-B-pheneth~lam1ne ~agu et a14.438,106 EPA and OHA deodorized.
(fatty ac1ds) storage stable Masuda et al2 4.474.8l1 2-(2-fluoro-4- ant1- reduced eye b1phenyl~1)pro- 1nfla~atory 1rrltat10n.
plon1c ac1d ophthalm1c htgher concen-or salt trations. no s1de effects. hlghly soluble. long stab111ty. excellent pharmacological effects Sh1noda et al 4.4~8.995 ac1d add1t10n ant1-ulcer e~cellent water salt of (2'- solub111ty, good benz~loxycar- absorpt1on 1n d1ges-bonrl)phen~l t1ve tract, good trans~ n1- ant1-ulcer act1v1ty d1nomethyleyclo-hexanecarboxylate Ha~ash1 et al 4,4~9,944 PG12 analog for treatment of stab111zat10n aga1nst artereoscleros1s, decompos1t10n cardlac fa11ure or thrombos1s ~5 ~ l 3 3 6 ~ 9 8 U.S. AC~IVE
I m ~TORPATE~T ~0. I~6REDlEhr USE ADY~T~6E
~ayasht et al 4.479.966 6.9-methano- for hypertens10n. 1ncreased stab111ty P6I2 analogs cerebral throm-bos1s and the 11ke Harada et al 4.497.803 lankac1d1n- ant1b10t1c for erh-~ced ~Rter group ant1b10t1c s~1ne dysentery solub111ty and stab111ty. 1ncreased rate and amount of absorpt10n ~asuda 4,499,085 prostagland1n treat1ng anox1a analog of bra1n cells S2ejtll et al 4.518.588 phend111ne. 1.e. coronary d11ator 1mproved ~ater solu-~-(l-phenyl- calc1um b111ty. accelerated ethyl)-3.3- antagon1st and lncreased 1n d1phenylpro- v1vo resorpt10n pyla~1ne or 1ts ~ d1ssolut10n at pH/
hydrochlor1de t~. -rat~e of gastr1c ac1d Szejtl1 et al 4.524.068 p1peronyl synerg1zes eas11y handled butox1de pest1c1dal effect crystall1ne sol1d;
of kno~n 1nsectl- improved water solu-cldes and fung1- b111ty, 1ncreased c1des absorpt10n ~ veloc1ty of penetrat10n through b1010g1cal 7~ S
JoneS 4.555.504 a card1ac card1ac effect h1gh a~ueous solu-glycos1de b111ty, apparently better b10ava11-ab111ty Uekama et al3 4.565.807 p1rprofen ant1-1nflam- 1mproved stab111ty matory. to ox1dat10n.
analges1c. freedom from b1tter ant1pyret1c taste. less 1rr1ta-t1ng U.S. ACTIVE
I~nE~TOR PATE~T ~0. I~6REDIE~T U5E ~D~A~rh6E
Ueda et al 4.575.548 2-n1tro~ th~l- for vascular non-volat11e po~der 6-chlorop~r1d1ne d1sorders vs. volat1ve oll Oh~a~1 et al~ 4,598.070 tr1pam1de ant1-hyper- 1mproved solubil1t~
tens1ve Ch1es1 et a1 4,603.123 p1rox1cam. 1.e. ant1-1nflam-4-h~droxy-2- ~ator~. analges1c methyl-N-2-p~r1d~1-2H-1.2-ben~oth1a~ine-3-carboxam1de-1.1-d10x1de Hasega~a et al 4.608.366 mobenzoxam1ne. ant1emet1c. storage stab11it~, 1.e. 1-[2-(4- ant1spasmod1c better absorption meth~ ~bcr.~h~- through digest1ve drylox~)ethyl]- tract 4-[3-(4-fluoro-benzorl)prop~l]-pipera~1ne H1ra1 et al2 4,659,696 pol~pept1de 1mprov1ng drug absorpt10n b~ non-oral and non-1nject1on routes Sze~tl1 et al 4,623,641 PGI2 methyl ant1-ulcer 1mproved storage ester stabil1ty N1nger et al 4,663,316 unsaturated ant1b10t1c. enhanced stabil1ty phosphorus- ant1fungal, against ox1dation conta1n1ng ant1tumor ant1b1ot1cs, 1nclud1ng phosphotrten1n I~YEtrn~ ~hTEhr ~0. 1~6REDIE~r U5E ADVo~T~EE
Fuka~a~a et al ~,675,395 h1nok1t101 bacter1c1dal, i~proved ~ater bacter10stat1c solub111ty, less odor 1 Tuttle also descr1bes use of 2.6-d1-0-methyl-0-cyclodextr1n and 2,3,6-tr1-0-methyl-~-c~clodextr1n to form the 1nclus~on co~plex.

2 Th1s ma~ not be an 1nclus10n complex, but s1~pl~ a phys1cal ~1xture.

3 Th1s 1s a m1xture and/or an 1nclus10n r_ Q d.
The 1nventors also ment10n pr10r known solub111ty i r~.~ nts of cyclodextr1n inclus10ns of barbitur1c acid derivat1ves, mefenam1c acid, indomethacin and chlor Iph~ 1col.
S The 1nventors refer to th1s as an ~occlus10n~ cc ~u~d.

` 1 336498 ~nclusion complexes of 2,6-di-0-methyl-B-cyclodextrin with dibenzo~bd~pyran derivatives and salts having analgesic, antemetic and narcosis-potentiatlng activities have been described in Nogradi et al U.S. Patent No. 4,599,327; increased water solu-bility and thus improved biological activity have been claimed for the complexes. A review of the pharma-ceutical applications of such methylated cyclodextrins has been published by Uekama, Pharm. Int., March 1985, 61-65; see also Pitha, Journal of Inclusion Phenomena 2, 477-485 (1984).
Cyclodextrin polymer has been reported by Fenyvesi et al, Chem. Pharm. Bull. 32 (2), 665-669 (1984) to improve the dissolution of furosemide. Improvements in the dissolution and absorption of phenytoin using a water-soluble B-cyclodextrin epichlorohydrin polymer have been described by Uekama et al, ~nternational Journal of Pharmaceutics, 23, 35-42 (1985).
Hydroxypropyl-B-cyclodextrin (~PCD) and its preparation by propylene oxide addition to B-cyclodextrtn were described in Gramera et al United States Patent No. 3,459,731 nearly 20 years ago.
Gramera et al also described the 2nalogous prepara-tion of hydroxyethyl-~-cyclodextrin by ethylene oxide reaction with ~-cyclodextrin. Much more recently, Pitha and co-workers have described the improved preparation of this cyclodextrin derivative and its effects on the dissolution of various drug molecules.
Pitha United States Patent No. 4,596,795, dated June 24, 1986, describes inclusion complexes of sex hormones, particularly testosterone, progesterone, and estradiol, with specific cyclodextrins, preferably hydroxypropyl--9- ` 1 336498 ~-cyclodextrin and poly-~-cyclodextrin. The complexes enable the sex hormones to be successfully delivered to the systemic circulation via the sublingual or buccal route; the effectiveness of this delivery is believed to be due to "the high dissolution power of hydro-philic derivatives of cyclodextrins, the non-aggregated structure of their complexes with steroids, and their low toxicity and irritancy of mouth tissue". Success with other cyclodextrins, including poly-y-cyclodextrin and hydroxypropyl-y-cyclodextrin, have also been noted in the Pitha patent. See also Pitha et al, J. Pharm.
Sci., Vol. 74, No. 9, September 1985, 987-990, con-cerning the same and related studies. Pitha et al also describe in the J. Pharm. Sci. article the storage stability of tablets containing a testosterone-hydroxypropyl-~-cyclodextrin complex and the lack of toxicity of the cyclodextrin itself, as well as the importance of the amorphous nature of the cyclodextrin derivatives and their complexes with drugs in improving dissolution properties.
The improved, optimized preparation and purifi-catton of hydroxypropyl-B-cyclodextrin has been recently described by Pitha et al, International Journal of Pharmaceutics, 29, 73-82 (1986). In the same publication, the authors have described increased water solubility for 32 drugs in concentrated (40 to 50~) aqueous solutions of hydroxypropyl-B-cyClodextrin;
improved solubilization of acetamidophen, apomorphine, butylated hydroxytoluene~ chlorthalidone, cholecalci-ferol, dexamethasone, dicumarol, digoxin, diphenyl-hydantoin, estradiol, estriol, ethinylestradiol-3-methyl ether, ethisterone, furosemide~ hydroflu-methiazide, indomethacin, iproniazid phosphate, 17-- lo- 1 3 3 6 4 9 8 methyltestosterone, nitroglycerin, norethindrone, ouabain, oxprenolol, progesterone, ret~nal, retinoic acid (all trans and salt forms), retinol, spironolac-tone, sulpiride, testosterone and theophylline was noted. The authors indicated this to be an extension of their earlier work with hydroxypropyl-B-cyclodex-trin, which was previously found effective for oral administration of the sex hormones to humans. Their later work reported in Pitha et al, International Journal of Pharmaceutics, 29, 73-82 (1986), has also been very recently described in Pitha United States Patent No. 4,727,064, dated February 23, 1988. That patent claims a composition containing an amorphous complex of cyclodextrin and a drug, and a method of producing a stabilizing amorphous complex of a drug and a mixture of cyclodextrins comprising (1) dissolving an intrinsically amorphous mixture of cyclodextrin derivatives which are water soluble and capable of forming inclusion complexes with drugs in water; and (2) solubilizing lipophilic drugs into aqueous media to form a solution and form a solubilized drug/cyclo-dextrin complex.
Uekama et al, CRC Critical Reviews in Therapeutic Drug Carrier Systems, Vol. 3 (1), pp. 1-40 (1987), have described the characteristics of various cyclodextrins, including hydroxypropyl-B-cyclodextrin. The authors have presented data showing improved solubilization in water in the presence of 15 mg/mL of HPC~ for the drugs carmofur, diazepam, digitoxin, digoxin, flurbiprofen, indomethacin, isosorbide dinitrate, phenytoin, prednis-olone, progesterone and testosterone. In a discussion of the metabolism and toxicity of cyclodextrins, Uekama et al have indicated that cyclodextrins at sufficiently high concentrations cause hemolysis, and that the methylated cyclodextrins have higher hemolytic activity than the natural cyclodextrins. Hydroxypropyl-B-cyclodextrin is said to cause hemolysis beginning at4.5 mM. The authors have further indicated that parenteral administration of large doses of cyclodex-trins should be avoided, but that ~-cyclodextrin and hydroxypropyl-B-cyclodextrin seem to be useful in drug solubilization for injections and liquid preparations used for mucous membranes."
JANSSEN PHAR~ACEUTICA N.V.'s International Patent Application ~o. PCT/EP84/00417, published under Inter-national Publication No. W085/02767 on July 4, 1985, has described pharmaceutical compositions comprising inclusion compounds of drugs, which are unstable or only sparingly soluble in water, with partially etherified B-cyclodextrin derivatives having hydroxy-alkyl and optionally additional alkyl groups. Among the cyclodextrin derivatives contemplated is hydroxy-propyl-B-cyclodextrin, while the drugs include non-steroidal anti-rheumatic agents, steroids, cardiac glycosides and derivatives of benzodiazepine, benzi-midazole, piperidine, piperazine, imidazole and triazole. Preferred drugs include etomidate, keto-conazole, tubulazole, itraconazole, levocabastine and flunarizine. The pharmaceutical compositions of the invention include oral, parenteral and topical formu-lations, with 4 to 1n~ solutions of cyclodextrin derivatives being utilized to solubilize various drugs. Improved solubilities of indomethacin, digi-toxin, progesterone, dexamethasone, hydrocortisone and diazepam using 10~ HPCD are shown, and an injectable formulation of diazepam in 7~ HPCD is specifically described. The relatively low cyclodextrin concen-trations used reflect a desire to avoid or minimize the hemolytic effects observed at higher cyclodextrin con-centrations.
Carpenter et al, The Journal of Pediatrics? 111, 507-512 (October 1987) descr~be intravenous infusion of 2-hydroxypropyl-~-cyclodextrin, prepared as a 5X solu-tion in water, to treat severe hypervitaminosis ~. It was found that, during infusion, circulating retinyl esters increased transiently, while total vitamin A
excreted in the urine was enhanced after infusion.
Thus, intravenous infusion of 5~ HPC~ was found to decrease in vivo levels of the vitamin, presumably by complexing with the vitamin and removing some of the excess from the body.
The inclusion characteristics of yet other deri-vatized cyclodextrins have also been described in the literature. Studies of branched cyclodextrins which are glucosyl and maltosyl derivatives of -, ~- and y-cyclodextrin and their inclusion complexes with drugs have recently been reported. Uekama, in Topics in Pharmaceutical Sciences 1987, eds. D. D. Breimer and P. Speiser, Elsevier Science Publishers B. V.
(Biomedical Division), 1987, 181-194, has described the effects on bio-pharmaceutical properties of maltosyl and glucosyl cyclodextrin derivatives, including enhanced drug absorption. Koizumi et al, Chem. Pharm. Bull. 35 (8), 3413-3418 (1987), have reported on inclusion complexes of poorly water-soluble drugs with glucosyl cyclodextrins, namely 6-0-~-D-glucosyl-~-CD (Gl-~-CD), 6-0-~-D-glucosyl-~-CD (Gl-~-CD) and 6A, 6D-di-O-~-D-glucosyl-~-CD (2G1-~-CD).
Okada et al, Chem. Pharm. Bull., 36 (6), 2176-2185 (1988), have reported on the inclusion complexes of poorly water-soluble drugs with maltosyl cyclodextrins, namely 6-o-a-maltosyl-a-cD (G2-a-CD), 6-0-~-maltosyl-B-cD (G2-~-CD), 6-0-~-maltosyl-y-CD (G2-y-CD), 6-0-~-maltotriosyl-~-CD (G3-~-CD), 6-o-a-maltotriosyl-B
CD (G3-3-CD) and 6-0-~-maltotriosyl-y-CD (G3-y-CD).
The delivery of drugs to the brain i 5 often seriously limited by transport and metabolism factors and, more specifically, by the functional barrier of the endothelial brain capillary wall, i.e. the blood-brain barrier or BBB. Site-specific delivery and sustained delivery of drugs to the brain are even more difficult.
A dihydropyridine ~ pyridinium salt redox system has recently been successfully applied to delivery to the brain of a number of drugs. Generally speaking, according to this system, a dihydropyridine derivative of a biologically active compound is synthesized, which derivative can enter the CNS through the blood-brain barrier following its systemic administration. Subse-quent oxidation of the dihydropyridine species to the corresponding pyridinium salt leads to delivery of the drug to the brain.
Three main approaches have been published thus far for delivering drugs to the brain using this redox system. The first approach involves derivation of selected drugs which contain a pyridinium nucleus as an integral structural component. This approach was first applied to delivering to the brain N-methylpyridinium-2-carbaldoxime chloride (2-PAM), the active nucleus of which constitutes a quaternary pyridinium salt, by way of the dihydropyridine latentiated prodrug form thereof. Thus, a hydrophilic compound (2-PAM) was made lipoidal (i.e. lipophilic) by making its dihydropyri-dine form (Pro-2-PAM) to enable its penetration through lipoidal barriers. This simple prodrug approach allowed the compound to get into the brain as well as other organs, but this manipulation did not and could not result in any brain specificity. On the contrary, such approach was delimited to relatively small mole-cule quaternary pyridinium ring-containing drug species and did not provide the overall ideal result of brain-speciflc, sustained release of the desired drug, with concomitant rapid elimination from the general circu-lation, enhanced drug efficacy and decreased toxi-city. No "trapping" in the brain of the 2-PAM formed in situ resulted, and obviously no brain-specific, -sustained delivery occurred as any consequence there-of: the 2-PAM was eliminated as fast from the brain as it was from the general circulation and other organs.
Compare U.S. Patents Nos. 3,929,813 and 3,962,447;
Bodor et al, J. Pharm. Sci, 67, No. 5, 685 (1978). See also Bodor, "Novel Approaches for the Design of ~embrane Transport Properties of Drugs", in Design of 8topharmaceutical Properties Through Prodrugs and Analogs, Roche, E.B. (ed.), APhA Academy of Pharmaceutical Sciences, Washington, D.C., 98-135 (1976). Subsequent extension of this first approach to -15- l 3 3 6 4 9 8 delivering a much larger quaternary salt, berberine, to the brain via its dihydropyridine prodrug form was, however, found to provide site-specific sustained delivery to the brain of that anticancer agent. See Bodor et al, Science, Vol. 214, ~ecember 18, 1981, pp.
1370-1372.
The second approach for delivering drugs to the brain using the redox system involves the use of a pyridinium carrier chemically ltnked to a bio10gically active compound. Bodor et a1, Science, Vol. 214, Oecember 18, 1981, pp. 1370-1372, outline a scheme for this specific and sustained delivery of drug species to the brain, as depicted in the following Scheme I:

IWNCI
t~ ~ ~cr~

DELlV~n/~ / ~
~ ~ \ /ELltU~TlOII
~DHCI ~D-OHCI
CtC~ r sn UO o~
1~ VIVO 11~ VIVO
oxloArlo~( Iox~oArlo lO~CI~ e~TJC ~rA~lc ID~CI-r~ ~ I CL~VA6E CLEAVAGE 1~ Cl~ AToa~ SYSrEI~I

tDI ~ll IDI ' IJl 1~3 BU \~

~LI-IIII~TIOh Sa~ 1: BBa, Blood -Bra~rl Bar~i c~

-17- l 3 3 6 4 9 8 ~ccording to the scheme in Science, a drug [D] is coupled to a quaternary carrier [QC]+ and the tD-QC]+
which results is then reduced chemically to the lipoidal dihydro form [n-DHC]. After administration of tD-DHC] in vivo, it is rapidly distributed throughout the body, including the brain. The dihydro form [D-OHC] is then in situ oxidized (rate constant, kl) (by the NAD ~ NADH system) to the ideally inactive original tD-QC]+ quaternary salt which, because of its ionic, hydrophilic character, should be rapidly eliminated from the general circulation of the body, while the blood-brain barrier should prevent its elimination from the brain (k3~k2; k3>~k7). Enzymatic cleavage of the [D-nC~+ that is "locked" in the brain effects a sustained delivery of the drug species tD], followed by its normal elimination (k5), metabolism. A properly selected carrier [QC]+ will also be rapidly eliminated from the brain (k6 k2). ~ecause of the facile elimination of [D-QC]+ from the general circulation, only minor amounts of drug are released in the body [k3 k4); [D] will be released primarily in the brain (k4>k2). The overall result ideally will be a brain-specific sustained release of the target drug species. Specifically, Bodor et al worked with phenyl-eth~lamine as the drug model. That compound wascoupled to nicotinic acid, then quaternized to give compounds of the formula which were subsequently reduced by sodium dithionite to the corresponding compounds of the formula CONHCH2CH2~3 (R ~ CH3 or CH ~ ).

R

Testing of the N-methyl derivative in vivo supported the criteria set forth in Scheme I. Bodor et al speculated that various types of drugs might possibly be delivered using the depicted or analogous carrier systems and indicated that use of N-methylnicotinic acid esters and amides and their pyridine ring-substituted derivatlves was being studied for deliveryof amino- or hydroxyl-containing drugs, including small peptides, to the brain. No other possible specific carriers were disclosed. Other reports of this work with the redox carrier system have appeared in The Friday Evening Post, August 14, 1981, ~ealth Center Communications, University of Florida, Gainesville, Florida; Chemical ~ Engineering News, ~ecember 21, 1981, pp. 24-25; and Science News, January 2, 1982, Yol. 121, No. 1, page 7. ~ore recently, the redox carrier system has been substantially extended in terms of possible carriers and drugs to be delivered. See International Patent Application No. PCT/US83/00725, filed ~ay 12, 1983 and published November 24, 1983 under International Publication No. W083/03968. Also see Bodor et al, Pharmacology and Therapeutics, Vol.
19, No. 3, pp. 337-386 (1983); and Bodor United States Patent No. 4,540,564, issued September 10, 1985.

- lg- 1 3 3 6 4 9 8 ~ he third approach for delivering drugs to the brain using the redox system provides derivatives of centrally acting amines in which a primary, secondary or tertiary amine function has been replaced with a dihydropyridine/pyridinium salt redox system. These brain-specific analogs of centrally acting amines have been recently described in International Patent Appli-cation No. PcT/us8s/oo23fi~ filed February 15, 1985 and published September 12, 1985 under International Publi-cation ~o. W085/03937. The dihydropyridine analogs are characterized by the structural formula D -~J

wherein D is the residue of a centrally acting primary, secondary or tertiary amine, and -N~ is a radical of the formula ( R ) ~ ~J o r ~J
~) (b) (c~ (d) wherein the dotted line in formula (a) indicates the presence of a double bond in either the 4 or 5 position of the dihydropyridine ring; the dotted line in formula (b) indicates the presence of a double bond in either the 2 or 3 position of the dihydroquinoline ring system; m is zero or one; n iS zero, one or two; p is 1 33~498 zero, one or two, provided that when p is one or two, each R in formula (b) can be located on either of the two fused rings; q is zero, one, or two, provided that when q is one or two, each R in formula (c) can be located on either of the two fused rings; and each R is independently selected from the group consisting of halo, C1-C7 alkyl, C1-C7 alkoxy, C2-C8 alkoxycarbonyl, C~-C8 alkanoyloxy, Cl-C7 haloalkyl, C1-C7 alkylthio, Cl-C7 alkylsulfinyl, C1-C7 alkylsulfonyl, -CH~NOR''' wherein R''' is H or Cl-C7 alkyl, and -CONR'Q'' wherein R' and R'', which can be the same or different, are each ~ or Cl-C7 alkyl. These dihydropyridine analogs act as a de1ivery system for the corresponding biologi-cally active quaternary compounds in vivo. Due to its 1~ lipophilic nature, the dihydropyridine analog will distribute throughout the body and has easy access to the brain through the blood-brain barrier. Oxidation in vivo will then provide the quaternary form, which will be "locked" preferentially in the brain. In con-tradistinction to the drug-carrier entities described in Bodor U.S. Patent ~o. 4,540,564 and related publica-tions, however, there is no readily metabolically cleavable bond between drug and quaternary portions, and the active species delivered is not the original drug from which the dihydro analog was derived, but rather is the quaternary analog itself.
~ ach of the major dihydropyridine pyridinium redox systems for brain-targeted drug delivery thus has its own unique characteristics but also has properties in common with the other approaches. Common to the various approaches is introduction of a dihydropyri-dine-type nucleus into the drug molecule, which renders -21- l 3 3 6 4 9 8 the dihydropyridine-containing drug derivative substantially more lipophilic than the parent drug from which it is derived. The increased lipophilicity enables the derivative to readily penetrate biological S membranes, includ~ng the blood-brain barrier. Also common to the various approaches is the fact that the ~redoxU nature of the dihydropyridine-type moiety means that the lipophilic dihydropyridine form is oxidizable in vivo to the hydrophilic, ionic pyridinium salt form, thus locking in the brain either the active drug or the quaternary precursor, depending on which approach is employed.
The dihydropyridine , pyridinium salt redox carrier and analog systems have achieved remarkable success in targeting drugs to the brain in laboratory tests. This success is, of course, due in part to the highly lipophilic nature of the dihydropyridine-containing derivatives, which allows brain penetra-tion. At the same time, the increased lipophilicity makes it practically impossible to formulate aqueous solutions of these derivatives for injection; moreover, even when the dthydropyridines are dissolved in organic solvents such as dimethylsulfoxide, they have a propensity for precipitating out of solution upon injection, particularly at higher concentrations, and especially at the injection site or in the lungs.
Indeed, even in the absence of noticeable crystalli-zation, it has been found that the redox derivatives frequently display not only the desired concentration in the brain but undesired lung concentrations as well, so that while the brain to blood ratios are at appropriate high levels, the initial lung to brain -22- l 3 3 6 4 9 8 levels are high as well. Still further, the dihydro-pyridine-containing derivatives suffer from stability Droblems, since even in the dry state they are very sensitive to oxidation as well as to water addition.

- 5 These problems, which must be overcome so that the dihydropyridine + pyridinium salt redox systems can be fully commercialized, have been addressed by appli-cant's copending Canadian Application No.
filed December 13, 1988 and are also addressed by the present application. In particular, the present application addresses the problems related to unfavorable concentration/precipitation of the dihydropyridine + pyridinium salt redox systems at or near the injection site and/or in the lungs, following parenteral administration, as well as similar problems encountered with other drugs which are insoluble, sparingly soluble and/o~ unstable in water.

SUMMARY AND OBJECTS OF THE INVENTION:
One object of the present invention is to provide improved aqueous parenteral solutions of drugs which are insoluble, sparingly soluble and/or unstable in water.
Another object of the present invention is to pro-vide a method for decreasing the tendency of lipophilic and/or water-instable drugs to precipitate at or near the injection site and/or in the lungs following parenteral drug administration.
Yet another object of the present invention is to provide improved aqueous parenteral solutions containing the reduced, dihydropyridine form of a -23- - l 336498 dihydropyridine + pyridinium salt redox system for brain-targeted drug delivery.
Still another object of the present invention is to provide a method for decreasing the tendency of the reduced, dihydropyridine form of a dihydropyridine pyridinium salt redox system for brain-targeted drug delivery to precipitate at or near the injection site and/or in the lungs following parenteral administration.
The foregoing objects are achieved by means of aqueous parenteral solutions of drugs which are in-soluble, sparingly soluble and/or unstable in water, said solutions comprising from about 20 to about 50Z of a hydroxypropyl, hydroxyethyl, glucosyl, maltosyl or maltotriosyl derivative of B- or y-cyclodextrin. The invention provides a novel method for decreasing the tendency of lipophilic and/or water-unstable drugs to precipitate at or near the injection site and/or in the lungs or other organs following parenteral drug administration, said method comprising formulating said drug in an aqueous solution adapted for parenteral administration containing from about 20~ to about 50% of a hydroxypropyl, hydroxyethyl, glucosyl, maltosyl or maltotriosyl derivative of ~- or y-cyclodextrin. In one aspect of the invention, the drug is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine ~ pyridinium salt redox system for brain-targeted drug delivery.

BRIEF DESCRIPTION OF THE DRAWINGS:
Other objects and advantages of the present invention will be apparent from the following detailed description and accompanying drawings, in which:

-24- ~ 3 3 6 4 9 8 FIG. 1 is a pair of semi-logarithmic plots, the first comparing the concentrations of an estradiol-CDS.
17~-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyl-oxy]estra-1,3,5(10)-trien-3-ol, hereafter referred to 5 as E2-COS, in lung tissue in ~9 per gram dose following systemic administration to rats of either 15 mg/kg E2-CDS in dimethylsulfoxide (O) or 5 mg/kg E2-CDS
inclusion complex with hydroxypropyl-B-cyclodextrin (~) in water, corrected for dose, and the second comparing the lung concentrations of the quaternary cation, 17B-~ methyl-3-pyridinium)carbonyloxy]estra-1,3,5(10)-trien-3-ol, hereafter referred to as E2Q+ or Quat, following the same E2-COS administration; and FIG. 2 is a bar graph illustrating, at selected time points, the concentrations of the quaternary cation, E2Q+ or Quat, in the brain in ng per gram dose, following systemic administration to rats of either 15 mg/kg E2-CDS in dimethylsulfoxide (O) or 5 mg/kg E2-COS
inclusion complex with hydroxypropyl-B-cyclodextrin (-) in water, corrected for dose.

DETAILEO DESC~IPTION OF THE I~VENTION:
The term "lipophilic" is used herein to describe drugs which are lipid-soluble and hydrophobic, i.e.
which are insoluble or sparingly soluble in water.
The expression "parenteral" as used herein refers to routes of administration other than through the gastrointestinal tract or lungs, and to formulations for use in administering drugs by such routes. Thus, "parenteral" as used herein includes, for example, intramuscular, subcutaneous, intra-articular (i.e. into -25- l 3 3 6 4 9 8 the joint, which in turn includes intra-synovial, i.e.
into the synovial fluid) and, especially, intravenous routes and formulations. The words "parenteral" and ~injectable" are used interchangeably herein.
Numerous drugs suffer from problems associated with their lack of water solubility and/or lack of stability in water. These lipophilic and/or water-labile drugs cannot be practically formulated as aqueous parenteral solutions. Consequently, the drugs are either unavailable for injection at the present time, or they are available for injectable use only in combination with undesirable organic vehicles.
Injection of such vehicles is undesirable because of the systemic and local toxicity which can result. Some of the organic solvents commonly used as vehicles include dimethylacetamide (O~A), dimethylsulfoxide (DMSO), propylene glycol(PG), benzyl alcohol and ethanol. Examples of the toxicity associated with these solvents include central nervous system depression, nystagmus, lymphocytosis, liver and kidney damage, blood disorders, jaundice, weight loss, anemia, convulsions, hallucinations, mutagenic effects, cyanosis, hypotension, bronchial spasms, cardiac standstill and death.
Moreover, parenteral administration of lipophilic or water-labile drugs in organic vehicles can result in precipitation of the drug at and/or near the injection site and/or in the lungs or other organs, which in turn leads to increased toxicity. Precipitation of drugs in the lungs, for example, has led-to severe respiratory distress and even death in laboratory animals. On the other hand, when lack of a suitable solvent results in the fact that the drug is only available as an oral formulation, then bioavailability becomes a concern since drugs are frequently less bioavailable from oral delivery forms than they are from parenteral, especially intravenous, forms.
Among the lipophilic and/or ~ater-labile drugs which are contemplated for use in aqueous parenteral formulations in accord with the present invention, there can he mentioned antineoplastics (anticancer/
antitumor agents), sedatives, anti-inflammatory steroids, tranquilizers, anticonvulsants, antivirals, vitamins/nutritional factors, emetics, anticoagulants, cardiotonics (including cardiac glycosides), diuretics, non-steroidal anti-inflammatory agents (NSAID's), androgens, estrogens, vasodilators, antidepressants, hypnotics, antifungals, progestins, antiprotozoals, anesthetics, vasoconstrictors, hypoglycemics, anti-hacterials/antibiotics, platelet inhibitors, muscle relaxants, antiemetics, radiodiagnostics, antispas-modics, antiarrhythmics, carbonic anhydrase inhibitors, narcotic antagonists, narcotic agonists, mixed narcotic agonists-antagonists, pharmacologically active proteins such as peptide hormones, enzymes, antibodies and other biologically produced substances, anti-Parkinsonism/dopamineric agents and drugs for treating Alzheimer's disease.
Specific drugs contemplated for parenteral formu-lation with hydroxypropyl-g-cyclodextrin in accord with the present invention include antineoplastics such as chlorambucil, lomustine, melphalan, methotrexate, -27- l 336498 hexamethylmelamine, teniposide, etoposide, semustine (methyl CCNU), fazarabine (Ara-AC), mercaptopurine, tubulazole, carmofur, carmustine, amsacrine, bruceantin, diaziquone, didemnin 8, echinomycin and PCNU; anti-inflammatory steroids such as dexamethasone, hydrocortisone and prednisolone; estrogens such as 17B-estradiol, 17~-ethynylestradiol, ethynylestradiol 3-methyl ether and estriol; progestins such as norethindrone, norethindrone acetate, norgestrel, ethisterone, medroxyprogesterone acetate and proges-terone; anticonvulsants such as phenytoin (diphenyl-hydantoin); barbiturates such as pentobarbital, phenobarbital and secobarbital, variously useful as hypnotics, anticonvulsants and sedatives; antivirals such as vidarabine; vitamins/nutritional factors such as retinol (vitamin A), vitamin A-acetate, cholecalci-ferol and retinal, as well as other fat-soluble vitamins such as the E, n and K vitamins; emetics such as apomorphine; diuretics such as chlorthalidone, furosemide and spironolactone; anticoagulants such as dicumarol; cardiotonics such as digoxin and digitoxin;
non-steroidal antl-inflammatory agents such as indomethacin, piroxicam and flurbiprofen; androgens such as 17-methyltestosterone and testosterone;
steroidal hypnotics/anesthetics such as alfaxalone;
antidepressants such as sulpiride; antibiotics such as ampicillin and penicillin ~; coronary vasodilators such as nitroglycerin and flunarizine; hypnotics such as etomidate; carbonic anhydrase inhibitors such as acetazolamide; antifungals such as ketoconazole, ltraconazole, metronidazole benzoate and miconazole;
antiprotozoals such as flubendazole; anesthetics such as lidocaine; hypoglycemics such as acetohexamide;
anti-emetics such as dimenhydr~nate; ant~bacterials such as co-trimoxazole; dopaminergic agents such as L-~OPA; anti-~lzheimer's agents such as THA; benzodiaze-pines, for example chlordiazepoxide, diazepam,medazepam, oxazepam and lorazepam, variously useful as sedatives, hypnotics, anticonvulsants, tranquilizers and muscle relaxants; and prostaglandins, for example PGE's such as PGE1 (alprostadil), a vasodilator, and PGI2 (prostacyclin or epoprostenol), a platelet inhibitor.
In one particularly preferred embodiment of the present invention, the drug contemplated for use in the instant parenteral formulations is an antineoplastic.
Antineoplastics such as chlorambucil, lomustine, melphalan, hexamethylmelamine~ methotrexate, semustine.
teniposide, etoposide and fazarabine are particularly preferred.
In another preferred embodiment of the invention, the drug contemplated for use in the instant parenteral formulations is the steroidal anesthetic/hypnotic, alfaxalone.
In yet another preferred embodiment of the inven-tion, the drug contemplated for use in the instant parenteral formulations is the reduced, dihydropyridine form of a dihydropyridine + pyridinium salt redox system for brain-targeted drug delivery.
With respect to the redox system for brain-targeted drug delivery, the following definitions are applicable:

The term ''lipoidalU is intended to designate a redox motety wh1ch is lipid-soluble or lipophilic.
The terms "redox carrier system" and "redox analog systemU are intended to destgnate two d1fferent approaches to targeting drugs to the brain using a dlhydropyridine ~ pyridinium salt system; compounds representing either of these approaches are contem-plated for use with a selected cyclodextrin in accord with the present invention.
The redox carrier system provides for brain-targeted drug delivery by means of carrier-drugs, which in their reduced form, which is the form intended for administration, can be represented by the formula ~D-DHC]

wherein [0] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal form of a dihydropyri-dine I pyridinium salt redox carrier. In their oxidized form, which is the form "locked" in the brain from which the active drug is ultimately released, the carrier-drugs can be represented by the formula [D-QC]+ X~

wherein X~ is the anion of a non-toxic pharmaceutically acceptable acid, [D] is a centrally acting drug species 2~ and ~QC]+ is the hydrophilic, ionic pyridinium salt form of a dihydropyridine ~ pyridinium salt redox carrier. The redox carrier approach is discussed 30_ l 3 3 6 4 9 8 hereinabove in the section entitled "8ACKGROUND OF THE
INVENTION~; histortcally, the carrier system ~s the second type of redox system developed for delivering drugs to the brain.
Various aspects of the redox carrier system have been described in detail in Bodor United States Patent No. 4,479,932, issued October 30, 1984; Bodor United States Patent No. 4,540,564, issued September 10, 1985;
Bodor et al United States Patent No. 4,617,298, issued October 14, 1986; and UNIVERSITY OF FLORIDA's Inter-national Application No. PCT/US83/00725, published under International Publication No. W083/03968 on November 24, 1983.
The redox analog system provides for brain-targeted drug delivery by means of new compounds containing a dihydropyridine , pyridinium salt portion which, unlike the redox carrier, is not readily meta-bolically cleavable from the original drug molecule.
One redox analog approach, ~hich provides deriva-tives of centrally acting amines in which a primary, secondary or tertiary amine function has been replaced with a dihydropyridine ~ pyridinium salt redox system, is discussed hereinabove in the section entitled "BACK-GROUND OF TNE INVENTIONU; historically, this analog system is the third type of redox system developed for delivering drugs to the bra1n. Various aspects of this analog system are described in detail in UNIVERSITY OF
FLORIDA'S Internat~onal Application No. PCT/US85/00236, published under International Publication No.
~085/03937 on September 12. 1985.

-31- l 3 3 6 4 9 8 Another redox analog approach provides novel amino acids and peptides containing them which comprise a dihydropyridine ~ pyridinium salt portion, the redox system being appended directly or via an alkylene bridge to the carbon atom adjacent to the carboxyl carbon. These amino acids and peptides are described in detail in UNIVERSITY OF FLORIDA's copending Canadian Patent Application No. 563,439-3, filed April 6, 1988. Briefly, the novel redox amino acids in the reduced form have the structural formula k-H~ coo ~2>~\
Rl wherein Z is either a direct bond or C1-C6 alkylene and can be attached to the heterocyclic ring via a ring carbon atom or via the ring nitrogen atom; R1 is C1-C7 alkyl, C1-C7 haloalkyl or C7-C12 aralkyl when Z is attached to a ring carbon atom; R1 is a direct bond when Z is attached to the ring nitrogen atom R2 and R3, which can be the same or different, are selected from the group consisting of hydrogen, halo, cyano, C1-C7 alkyl, C1-C7 alkoxy, C2-C8 alkoxycarbonyl, C2-C8 alkanoyloxy, C1-C7 haloalkyl, C1-C7 alkylthio, C1-C7 alkylsulfinyl, C1-C7 alkylsulfonyl, -CH=NOR''' wherein R''' is hydrogen or Cl-C7 alkyl, and -CONR'R'' wherein R' and R'', which can be the same or different, are each hydrogen or Cl-C7 alkyl; or one of R2 and R3 together with the adjacent ring carbon atom forms a benzene ring fused to the heterocyclic ring, which benzene ring may optiona11y bear one or two substi-tuents, which can be the same or different, selected from the group consisting of hydroxy, protected hydroxy, halo, cyano, C1-C7 alkyl, Cl-C7 alkoxy, C2-C8 alkoxycarbonyl, C2-C8 alkanoyloxy, C1-C7 haloalkyl, C1-C7 alkylthio, Cl-C7 alkylsulfinyl, G1-C7 alkylsulfonyl, -CH=NOR''' wherein R''' is hydrogen or C1-C7 alkyl, and -COHR'R'' wherein R' and R'', which can be the same or different, are each hydrogen or Cl-C7 alkyl; R4 is hydrogen or a carboxyl protective group; R5 is hydrogen or an amino protective group; and the dotted lines indicate that the compound contains a 1,4- or 1,6-dihydropyridine, a 1,4- or 1,2-dihydroquinoline, or a 1,2-dihydroisoquinoline ring system.
The new dihydropyridine amino acid analogs depicted above and the corresponding oxidized forms are useful in the preparation of novel redox peptides of the partial formulas:

~co-R2 ~\
~ R~

(~educe~ fo~) 33 l 3 3 6 4 9 8 nd -~lll-;H-CO-~H~- l (B~

(ox1dl~ed for--) the new peptide analogs of partial structure (A) act as a delivery system for the corresponding quaternary salts of partial structure (8) in vivo the quaternary derivatives, which also are chemical intermediates to the dihydro compounds, are pharmacologically active or convertible in vivo to pharmacologically active peptides, and are characterized by site-specific and sustained delivery to the brain when administered via the corresponding dihydropyridine form. ~ethods for the preparation of these analog amino acids and peptides utilize methods known in the art for intro-duction of the dihydropyridine ~ pyridinium salt moiety or a precursor thereof, e.g. from the aforementioned International Publications Nos. ~083/03968 and W085/03937, appropriately combined with well-known methods for peptide synthesis. Ultimately, the quaternary forms of the amino acids and peptides are subjected to reduction to afford the corresponding dihydropyridlnes, according to the methods of the Bodor -34- l 3 3 6 4 9 8 U.S. patents and above-mentioned published PCT
applications.
In a preferred aspect of the present invention, the redox system selected for use with a hydroxy-propyl, hydroxyethyl, glucosyl, maltosyl or malto-triosyl derivative of ~- or r-cyclodextrin in accord with the present invention is a redox carrier system.
The drug and carrier portions of the redox carrier system are described in more detail below and of course in the various carrier patents and patent applications identified above. Selection of appropriate drugs and carrier moieties need not be limited to specific drugs and specific carriers disclosed in the aforementioned patents and applications or in the present applica-tion, iust so long as the selected drug and carriermeet the general requirements of the drug/carrier system as described in the aforenoted documents.
rhe term "drug~ as used herein means any substance intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease or in the enhancement of desirable physical or mental develop-ment and conditions in man or animal.
~ y "centrally acting" drug species, active agent or compound as utilized herein, there is of course intended any drug species or the like, a significant (usually, principal) pharmacological activity of which is CNS and a result of direct action in the brain.
Exemplary such centrally acting drug species are the CNS-amtnes and other nervous system agents, whether sympathetic or parasympathetic, e.g., phenylethylamine (a stimulant), dopamine (a neurotransmitter and 1 3364~8 dopaminergic agent used, e.g., in the treatment of Parkinsonism or hyperpro1actinemia), tyramine (a stimulant), L-DOPA (a dopamine precursor used, for example, in the treatment of Parkinsonism); muscle relaxants, tranquilizers and antidepressants, e.g., benzodiazepine tranquilizers such as diazepam and oxazepam and phenothiazine tranquilizers such as carphenazine, fluphenazine and the like; mild and strong analgesics and narcotics; sedatives and hypnotics; narcotic antagonists; vascular agents;
stimulants; anesthetics; small peptides, such as the di-, tri-, tetra and pentapeptides, and other small 2-20 amino acid unit containing peptides, e.g. the enkephalins (for example, Tyr-Gly-Gly-Phe-Leu), which, besides being analgesics, initiate epileptic activity in the brain at doses that are about tenfold lower than for effecting analgesic activity; growth-promoting substances; antiepileptic and anticonvulsant drugs generally, including hydantoins such as phenytoin and ethotoin, barbiturates such as phenobarbital; hormones, such as the steroid hormones, e.g., estradiol, testosterone, 17 3-ethynyl testosterone (ethisterone), and the like (recent studies on histological mapping of hormone-sensitive and specific steroid binding cells in the brain have underscored the importance of the steroid action in the brain on sexual behavior);
amphetamine-like drugs; anticancer and anti-Park1nsonism agents; anti-hypertensives, agents to enhance learning capac~ty and the memory processes, including treatment of dementias, such as Alzheimer's disease, such as 9-amino-1,2,3,4-tetrahydroacridine;
antibacterials; centrally acting hypotensive agents;

centrally acting prostaglandins, such as PG02;
diagnostic agents, such as radiopharmaceuticals;
monoamine oxidase (~AO) inhibitor drugs; CNS or brain important/essential amino acids, such as tryptophan (which is an antidepressant as well as a nutrient); and any like centrally acting compounds. For the purposes of this invention, dopa or L-DOPA is not classified as an amino acid but rather as a CNS amine and dopa-minergic agent used, e.g. in the treatment of Parkinsonism.
Other illustrative ultimate species of centrally acting drug entities are: amphetamine, dextroamphet-amine, levamphetamine, aletamine, cypenamine, fencam-famin, fenozolone, zylofuramine, methamphetamine, phen-metrazine and phentermine, which are sympathomimeticamines/cerebral stimulants and appetite suppressants;
etryptamine, a cerebral stimulant; codeine, oxycodone, pentazocine, anileridine, hydromorphone, morphine and oxymorphone, which are narcotic analgesics; desipra-mine, nortriptyline, octriptyline, maprotiline,opipramol and protriptyline, which are cerebral stimulants/tricylic antidepressants of the dibenza-zepine type used, e.g., in endogenous depressions;
clonidine and methyldopa, which are sympatholytic agents used, e.g., in hypertension; biperiden, cycrimine and procyclidine, which are centrally acting anticholinergics; tranylcypromine, a sympathomimetic cerebral stimulant/MAO inhibitor and antidepressant;
acetophenazine, carphenazine, fluphenazine, perphenazine and piperacetazine, which are phenothlazine-type tranquilizers; benzoctamine, a sedative/muscle relaxant which structurally is an -~7-analogue of the phenothiazine tranquilizers; chlor-diazepoxide, clorazepate, nitrazepam and temazepam, which are benzodiazepine-type tranquilizers; noracy-methadol, a ndrcotic analgesic of the methadone type;
piminodine, a narcotic analgesic of the meperidine type; tracazolate, a sedative/hypotensive; prizidilol, a centrally acting hypotensive; sulpiride, an anti-depressant/psychotropic; haloperidol and clopenthixol, which are tranquilizers; norepinephrine, a sympathetic stimulant/adrenergic agent; nalorphine and naloxone, narcotic antagonists; hydralazine, a hypotensive;
ethotoin, phenobarbital and aminoglutethimide, anti-convulsants; epinephrine, an adrenergic agent;
ethamivan, a medullary stimulant; bemegride, a barbiturate antagonist; amiphenazole, a stimulanti iopydol, iodopyracet, iodouppurate (o-iodohippuric acid), iodamide and iopanoic acid, which are radiodiagnostics; ephedrine, pseudoephedrine, oxymetazoline and phenylephrine, which are sympatho-mimetic amines and decongestants; estradiol, estroneand estriol, the natural estrogens; amoxicillin, oxacillin, carbenicillin, benzylpenicillin, phenoxy-methylpenicillin, methicillin, nafcillin, ticarcillin, bacampicillin, epicillin, hetacillin, pivampacillin, the methoxymethyl ester of hetacillin, and ampicillin, which are penicillin-type antibiotics; amobarbital, a sedative; trihexyphenidyl, a centrally acting anticholinergic; hydroxyzine, a tranquilizer; chlorte-tracycline, demeclocycline, minocycline, doxycycline, oxytetracycline, tetracycline and methacycline, which are tetracycline-type antibiot1cs; flurazepam, bromazepam, demoxepam and lorazepam, benzodiazepine tranquilizers; phenytoin, an anticonvulsant;
glutethimide, a mild hypnotictsedative; clindamycin, lincomycin, nalidixic acid, oxolinic acid and phenazo-pyridine, antibacterials/antibiotics; bethanidine and guanethidine, hypotensives/sympatholytics; captopril, a hypotensive; methyprylon, a mild hypnotic; amedalin, bupropion, cartazolate, daledalin, d~fluanine, fluoxe-tine and nisoxetine, which are cerebral stimulants;
propranolol, a B-blocker antthypertensive; cloxacillin and dicloxacillin, penicillin-type antibacterials;
butalbital, d bar~iturate sedative; GA~A, y-vinyl GABA, ~-acetylenic GABA, neurotransmitters for possible use in epilepsy; valproic acid and its metabolites such as 5-hydroxy-2-n-propylpentanoic acid, 4-hydroxy-2-n-propylpentanoic acid, 3-hydroxy-2-n-propylpentanoic acid, for use as anticonvulsants; valpromide, a valproic acid derivative for use as an anticonvulsant;
apomorphine, a narcotic depressant/emetic which has been used in the treatment of photosensitive epilepsy;
pholcodine, a narcotic antitussive; methotrexate, mitoxantrone, podophyllotoxin derivatives (etopside, teniposide), doxorubicin, daunamycin and cyclophosphamide, anti-cancer/antitumor agents;
methylphenidate, a stimulant; thiopental, an anesthetic; ethinyl estradiol and mestranol, estrogens;
meptazinol, cyclazocine, phenazocine, profadol, metopon, drocode and myfadol, which are narcotic analgestcs; buprenorphine, nalbuphine, butorphanol, levallorphan, naltrexone, nalmefene, alazocine, oxtlorphan and nalmexone, whtch are narcotic antagontsts or agonist-antagonists; norgestrel and norethindrone, progestins; cephalothin, cephalexin, cefazolin, cefoxitin, moxalactam, ceforanide, cefroxadine and cephapirin, cephalosporin antibiotics;
atenolol, nadolol, timolol and metoprolol, B-blockers/hypotensives; ACTH (corticotropin), a hormone which stimulates glucocortlcoid production; LHRH, a neurotransmitter which stimulates secretion of the pituitary hormones, LH and FSH, and has been used to induce ovulation as well as for fertility control/
contraception; sulfadiazine an~ other sulfonamide antibiotics, ribavirin and acyclovir, antiviral agents;
chlorambucil and melphalan, nitrogen mustard-type anti-cancer/antltumor agents; methotrexate and aminopterin, which are folic acid antagonist-type anticancer/anti-tumor agents; platinum coordination complexes, i.e.
cisplatin analogue-type anticancer/antitumor agents;
dactinomycin and mitomycin C, used in cancer chemo-therapy; thioguanine, a purine/pyrimidine antagonist used in cancer treatment; vincristine and vinhlastine, anticancer alkaloids; hydroxyurea and DON, anticancer urea derivatives; FSH, HCG and HCS, pituitary and non-pituitary gonadotropins, used, for example, in certain reproductive disorders; N,N'-bis(dichloracetyl)-1,8-octamethylenediamine (fertilysin), an agent for male fertility inhibition; levorphanol, a narcotic anal-gesic; benzestrol and diethylstilbestrol, syntheticestrogens; ethyl B-carboline-3-carboxylate, a benzo-diazepine antagonist; furosemide, a diuretic/antihyper-tensive; dipyridamole and nifedipine, coronary vaso-dilators; and progabide, a GABA-agonist and prodrug of GAB~. Yet other ultimate species include non-steroidal antiinflammatory agents/non-narcotic analgesics, e.g.
propionic acid derivatives, acetic acid derivatives, fenamic acid derivatives and biphenylcarboxylic acid derivatives. Specific NSAID's/non-narcotic analgesics contemplated for combination with the redox carrier include ibuprofen, naproxen, flurbiprofen, zomepirac, sulindac, indomethacin, fenbufen, fenoprofen, indoproxen, ketoprofen, fluprofen, bucloxic acid, tolmetin, alclofenac, fenclozic acid, ibufenac, flufenisal, pirprofen, flufenamic acid, mefenamic acid, clonixeril, clonixin, meclofenamic acid, flunixin, diclofenac, carprofen, etodolac, fendosal, prodolic acid, sermetacin, indoxole, tetrydamine, diflunisal, naproxol, piroxicam, metazamide, flutiazin and tesicam.
Preferred classes of centrally acting drugs for combination with the redox carrier are the central neurotransmitters, steroids, anticancer and antitumor agents, antiviral agents, tranquilizers, memory enhancers, hypotensives, sedatives, antipsychotics and cerebral stimulants (especially tricyclic antidepressants). Among the neurotransmitters, there can be mentioned amino acids, such as GABA, GABA
derivatives and other omega-amino acids, as well as glycine, glutamic acid, tyrosine, aspartic acid and other natural amino acids; catecholamines, such as dopamine, norepinephrine and epinephrine; serotonin, histamine and tryptamine; and peptides such as neurotensin, luteinizing hormone-releasing hormone (LHRH), somatostatin, enkephalins such as metS-enkephalin and leuS-enkephalin, endorphins such as y-, a- and B-endorphins, oxytocin M and vasopressin.
Synthetic and semi-synthetic analogues, e.g. analogues of LHRH in which one or more amino acid(s) has/have been eliminated and/or replaced with one or more -41- l 3 3 6 4 9 8 different amino acid(s), and which may be agonists or antagonists, are also contemplated, e.g. the primary and secondary amine LHRH analogues disc1Osed in United States Patents No. 4,377,574, 3,917,825, 4,034,082 and 4,338,305. Among the steroids, there can be mentioned anti-inflammatory adrenal cortical steroids such as hydrocortisone, betamethasone, cortisone, dexamethasone, flumethasone, fluprednisolone, meprednisone, methyl prednisolone, prednisolone, prednisone, triamcinolone, cortodoxone, fludrocortisone, flurandrenolone acetonide (fluran-drenolide), paramethasone and the like; male sex hormones (androgens), such as testosterone and its close analogues, e.g. methyl testosterone (17-~ethyltestosterone); and female sex hormones, bothestrogens and progestins, e.g. progestins such as norgestrel, norethindrone, norethynodrel, ethisterone, dimethisterone, allylestrenol, cingestol, ethynerone, lynestrenol, norgesterone, norvinisterone, ethynodiol, oxogestone and tigestol, and estrogens such as ethinyl estradiol, mestranol, estradiol, estriol, estrone and quinestrol and the like. Among the anticancer and antitumor agents, there can be mentioned Ara-AC, pentostatin (2'-deoxycoformycin), Ara-C (cytarabine), 3-deazaguanine, dihydro-5-azacytidine, tiazofurin, sangivamycin, Ara-A (vitarabine), 6-MMPR, PCNU, FENU, HENU and other nitrosoureas, spiromustine, bisbenzimidazole, L-alanosine (6-diazo-5-oxo-L-norleucine), DON, L-ICRF, trimethyl TMM, 5-methyl-tetrahydrohomofolic acid, glyoxylic acidsulfonylhydrazone, DACH, SR-2555, SR-2508, desmethyl-misonidazole, mitoxantrone, menogarol, aclacinomycin A, -42- . 1 3 3 6 4 9 8 phyllanthoside, bactobolin, aphidocolin, homoharring-tonine, levonantradol, acivicin, streptozotocin, hydroxyurea, chlorambucil, cyclophosphamide, uracil mustard, melphalan, 5-FU (5-fluorouracil), 5-FUDR
(floxuridine), vincristine, vinblastine, cytosine arabinoside, 6-mercaptopurine, thioguanine, 5-azacytidine, methotrexate, adriamycin (doxorubicin), daunomycin (daunorubicin), largomycine polypeptide, aminopterin, dactinomycin, mitomycin C, and podophyl10toxin derivatives, such as etoposide (VP-16) and teniposide. Among the antiviral agents, there can be mentioned ribavirin, acyclovir (ACV); amantadine (also of possible value as an anti-Parkinsonism agent);
diarylamidines such as 5-amidino-2-(5-amidino-2-benzo-furanyl~indole and 4',6-diimidazolino-2-phenylbenzo-(b)thiophene; 2-aminooxazoles such as 2-guanidino-4,5-di-n-propyloxazole and 2-guanidino-4,5-diphenyloxazole;
benzimidazole analogues such as the syn and anti isomers of 6t[(hydroxyimino)phenyl]methylJ-l-t(l-methylethyl)sulfonyl]-lH-benzimidazol-2-amine;
bridgehead C-nucleosides such as 5,7-dimethyl-2-B-0-ribofuranosyl-s-triazole(1,5-a)pyrimidine glycosides such as 2-deoxy-0-glucose, glucosamine, 2-deoxy-2-fluoro-D-mannose and 6-amino-6-deoxy-D-glucose; phenyl glucoside derivatives such as phenyl-6-chloro-6-deoxy-B-D-glucopyranoside; (S)-9-(2,3-dihydroxypropyl)-adenine; tiazofurin; selenazofurin; 3-deazauridine; 3-deazaguanosine; DHPG; 6-azauridine; idoxuridine;
trtfluridine (trifluorothymidine); BDVU (bisdihydroxy-vinylurtdine); zidovudine (AZT); dideoxycytidine; and5,6-dichloro-1-B-0-ribofuranosylbenzimidazole. Among the anti-cancertantitumor and antiviral agents, those 43 l 3 3 6 4 9 8 of the nucleoside type (i.e. a purine or pyrimidine base-type structure bearing a singly or multiply hydroxylated substituent) are of particular interest.
This group includes such compounds as Ara-AC, pentostatin, Ara-C, dihydro-5-azacytidine, tlazofurin, sangivamycin, Ara-A, 6-~MPR, desmethylmisonidazole, 5-fUOR, cytosine arabinoside, 5-azacytidine, ribavirin, acyclovir, (S)-9-(2,3-dihydroxypropyl)adenine, 6-azauridine, 5,6-dichloro-1-~-D-ribofuranosyl-benzimidazole, 5,7-dimethyl-2-~-~-ribofuranosyl-s-triazole(l,5-a)pyrimidine, zidovudine (AZT~, dideoxycytldine, dideoxyadenosine, dideoxyinosine and D~P~. ~mong the tranquilizers, there can be mentioned benzodiazepine tranquilizers, such as diazepam, oxazepam, lorazepam, chlordiazepoxide, flurazepam, bromazepam, chlorazepate, nitrazepam and temazepam;
hydantoin-type tranquilizers/anticonvulsants such as phenytoin, ethotoin, mephenytoin; phenothiazine-type tranquilizers such as acetophenazine, carphenazine, fluphenazine, perphenazine and piperacetazine; and others. Among the hypotensives, there can be mentioned clonidine, methyldopa, bethanidine, debrisoquin, hydralazine, and guanethidine and its analogues. Among the sedatives, tranquilizers and antipsychotics, there can be mentioned the many specific compounds of this type disclosed above, especially the phenothiazines and benzodiazepines and their ana1ogues. Among the cerebral stimulants, there also can be mentioned the many specific compounds set forth hereinabove, parttcularly the sympathomimetic amine-type cerebral st1mulants and the tricyclic antidepressants, especially preferred tric~clics being the dibenzazepines and their analogues.
Also illustrative of the centrally acting drug species contemplated for combination with the redox carrier are centrally active metabolites of centrally acting drugs. Such metabolites are typtfied by hydroxylated metabolites of tricyclic antidepressants, such as the E- and Z-isomers of lO-hydroxynortripty-line, 2-hydroxyimipramine, 2-hydroxydesipramine and 8-hydroxychloripramine; hydroxy-lated metabolites of phenothiazine tranquilizers, e.g. 7-hydroxychlor-promazine; and desmethyl metabolites of ~-methyl benzodiazepine tranquilizers, e.g. desmethyl-diazepam. Other CNS active metabolites for use herein will be apparent to those skilled in the art, e.g. SL
75102, which is an active metabolite of progabide, a GABA agonist, and hydroxy-CCNU, which is an active metabolite of CCNU, an anti-cancer nitrosourea.
Typically, these CNS active metabolites have been identtfied as such in the scientific literature but have not been administered as drugs themselves. In many cases, the active metabolites are believed to be comparable in CNS activity to their parent drugs;
frequently, however, the metabolites have not been administered per se because they are not themselves able to penetrate the blood-brain barrier.
As indicated hereinabove, diagnostic agents, in-cluding radiopharmaceutical5, are encompassed by the expression Ucentrally acting drug" or the like as used herein. Any diagnostic agent which can be derivatized to afford a redox carrier system which will penetrate the BBB and concentrate in the brain in its quaternary form and can be detected therein is included. The diagnostic may be "cold" and be detected by X-ray ~e.g.
radiopaque agents) or other means such as mass spectrophotometry, NMR or other non-invasive techniques (e.g. when the compound includes stable isotopes such as C13, N15, 018, S33 and S34). The diagnostic alternatively may be "hot", i.e. radiolabelled, such as ~ith radioactive iodine (I 123, ~ 125, I 131) and detected/imaged by radiation detection/imaging means.
Typical "cold" diagnostics for derivation herein include o-iodohippuric acid, iothalamic acid, iopydol, iodamide and iopanoic acid. Typical radiolabelled diagnostics include diohippuric acid (I 125, I 131), diotyrosine (I 125, I 131), o-iodohippuric acid (I
131), iothalamic acid (I 125, I 131), thyroxine (I 125, I 131), iotyrosine (I 131) and iodometaraminol (I 123), which has the structural formula ~OH .
1~

In the case of diagnostics, unlike the case of drugs which are for the treatment of disease, the "locked in"
quaternary form will be the form that is imaged or otherwise detected, not the original diagnostic itself. ~oreover, any of the centrally acting drugs which are intended for the treatment or prevention of medlcal dtsorders but which can be radiolabelled, e.g.
with a radioisotope such as iodine, or labelled with a -46- l 336498 stable isotope, can thus be converted to a diagnostic for incorporation into the redox carrier system.
It will be apparent from the known structures of the many drug species exemplified above, that in many cases the selected drug will possess more than one re-active functional group, and, in particular, that the drug may contain hydroxyl or carboxyl or amino or other functional groups in addition to the groups to which the carrier will be linked, and that these additional groups will at times benefit from being protected during synthesis and/or during administration. The nature of such protection is described in more detail in the various patents and patent applications referred to herein. Obviously, such protected drug species are encompassed by the definition of "drug"
set forth hereinabove.
It too will be appreciated that by "dihydropyri-dine carrier" or "tDHC]", there is intended any non-toxic carrier moiety comprising, containing or in-cluding the dihydropyridine nucleus, ~hether or not apart of any larger basic nucleus, and whether substi-tuted or unsubstituted, the only criterion therefor being capacity for 8BB penetration and in vivo oxidation thereof to the corresponding quaternary pyridinium salt carrier [QC]+. As aforesaid, the ionic pyridinium salt drug/carrier prodrug entity [D-QC]+
which results from such ~n vivo oxidation is prevented from efflux from the brain, while elimination from the general circulation is accelerated. Subsequently, the covalent or equivalent bond coupling the drug species [D] to the quaternary carrier [QC]+ is metabolically cleaved, which results in sustained delivery of the drug [n~ in the brain and facile elimination of the carrier moiety CQC~+. Such "covalent or equivalent bond" between the drug and the quaternary carrier can be a simple direct chemical bond, e.g., an amide, an ester, or any other like bond, or same can even be comprised of a linking group or function, e.g., a thiazolidine bridge or a peptide linkage, typically necessitated when the drug species is not susceptible to direct chemical coupling to either the dihydropyri-dine carrier or the quaternary carrier. ~onetheless, the bond in the formulae [D-OC]+ and [D-OHC] j S
intended to be, and is hereby defined as inclusive of all such alternatives. And the cleavage of the C~-QC]+
prodrug to sustainedly deliver the drug species CD] in the brain with concomitant facile elimination of the carrier moiety ~QC]+ is characteristically enzymatic cleavage, e.g., by esterase, amidase, cholinesterase, hydrolytic enzyme, or peptidase.
The expression "non-toxic pharmaceutically accept-able salts" as used herein generally includes the non-toxic salts of the reduced, dihydropyridine forms of the redox carrier or redox analog systems, formed with nontoxic, pharmaceutically acceptable inorganic or organic acids HX. For example, the salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the li~e; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic. stearic, lactic, malic, tartartc, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, fumaric, methanesulfonic, tolu-enesulfonic and the like. The expression "anion of a non-toxic pharmaceutically acceptable acid" as used herein, e.g. in connection with the oxidized, pyri-dinium salt forms of the redox carrier or redox analog systems. is intended to include anions of such inorganic or organic acids HX.
In the discussion to follow, the expression "at least one reactive functional group selected from the group consisting of amino, hydroxyl, mercapto, carboxyl, amide and imide" or portions of that expres-sion are used. The functional groups designated in that expression have the following meanings:
The word "amino" means a primary or secondary amino function, i.e. -NH2 or -NHR. The secondary amino function is also represented herein as -NH-, particu-larly since the exact identity of the Q portion of -NHR
is immaterial, R being a part of the drug residue n itself which is left unchanged by conversion of the drug to the redox carrier system.
The word "hydroxyl" means an -OH function.
The word "carboxyl" means a -COOH function.
The word "mercapto" means an -SH function.
The word "amide" means a carbamoyl (-CONH2) or substituted carbamoyl (-CONHR) or a sulfamoyl (-S02NH2) or substituted sulfamoyl (-S02NHR) functional group.
The -CONHR and -S02NHR groups may also be represented herein as -CONH- and -502NH-, respectively, since the ldentity of R is immaterial, R being a part of the drug residue D itself which is left unchanged by conversion of the drug to the redox carrier system.

` 1 336498 The word "imide" means a functional group having the structure - C~
NH
- C
~0 that is, the structure which characterizes imides (i.e.
compounds having a succinimide-type or phthalimide-type structure).
~ any different dihydropyridine pyridinium salt redox carrier moieties are illustrated in the carrier patents and applications referred to hereinabove. The following is a list of representative major classes of dihydros and the corresponding quaternaries, but is not meant to be exhaustive;
(1) For linkage to a drug having at least one hydroxyl or mercapto or primary or secondary amino functional grouping, replacing a hydrogen atom from at least one of said functional groupings with one of the following ~DHC] groupings:

C~

Rl R3-oC-(-') (b') O O
2C- ~COI-(C') (d') O O
~X ~COCH2C-R3 -oCl - R 1 (e') (f') C- ~3 o (9') (h') ~ COCH2C-O') wherein the dotted line in formulas (a'), (b') and (c'~
indicates the presence of a double bond in either the 4 or S position of the dihydropyridine ring; the dotted line in formulas (d'), (e'~ and (f') indicates the S presence of a double bond in either the 2 or 3 position of the dihydroquinoline ring; ~1 is C1-C7 alkyl, C1-C7 haloalkyl or C7-C10 aralkYl; R3 is Cl to C3 Y
is -CONR'R'', wherein Q' and ~'', which can be the same or different, are each H or Cl-C7 alkyl, or X is -CH=NOR''' wherein R''' is ~ or Cl-C7 alkyl; the carbonyl-containing groupings in formulas (a'~ and (c'~
and the X substituent in formula (b') can each be attached at the 2, 3 or 4 position of the dihydropyri-dine rtng; the carbonyl-containing groupings in formulas (d'~ and (f') and the X substituent in formula (e'~ can each be attached at the 2, 3 or 4 position of the dlhydroquinoline ring; and the carbonyl-containing groupings in formulas (g') and (j') and the X substi-tuent in formula (h') can each be attached at the 1, 3 or 4 position of the dihydroisoquinoline ring.
(2) For 1inkage to a drug having at least one carboxyl functional grouping, replacing a hydrogen atom from at least one of said carboxyl groupings with one of the following ~HC] groupings:
(a) When there are one or more -COOH groups to be derivatized:

~;~c~-z~ x Rl ~3-C-Q-~ -(1') (11') - !~ 2 -c~_Q z~ ~0 ~i'? (iV') O O
~X ~COCH2C-Q-Z'- .

R3-C-q-Z'- , Rl (v~) (vi') ~ 3 c Q z~- , or (v11 ' ) (viii ' ) ~1 2C Q z -wherein the dotted line in formulas (i'~, (ii'~ and (iii'~ indicates the presence of a double bond in either the 4 or 5 position of the dihydropyridine ring;
the dotted line in formulas (iv'), (v'~ and (vi') indicates the presence of a double bond in either the 2 or 3 position of the dihydroquinoline ring; Z' is Cl-C8 straight or branched alkylene, preferably Cl-C3 straight or branched alkylene; Q is -O- or -NH-; R1 is Cl-C7 alkyl, Cl-C7 haloalkyl or C7-C10 aralkyl; R3 is C1-C3 alkylene; X is -CONR'R'' wherein R' and R'', which can be the same or different, are each H or Cl-C7 alkyl, or X is -CH=NOR''' wherein R''' is H or C1-C7 alkyl; the X substituent in formula (ii') and the carbonyl-containing grouping in formulas (i'~ and (iii') can each be attached at the 2, 3 or 4 position of the dihydropyridine ring; the X substituent in formula (v') and the carbonyl-containing groupings in formulas (iv') and (vi') can each be attached at the 2, 3 or 4 position of the dihydroquinoline ring; and the X
substituent in formula (viii') and the carbonyl-containing groupings in formulas (vii') and tix'~ caneach be attached at the 1, 3 or 4 position of the dihydroquinoline ring;
(b) Alternatively, ~hen there is only one -COOH group to be derivatized:

(R~,)5~ ,__~
(R") (x') (x1') " ~ ~

N ~ (A)nV

(xt1 ' ) ~ c~ ~ J (x111 ) or Rl (A)nV

~ j~/
(A)nv wherein the dotted line in formula (xii') indicates the presence of a double bond in either the 4 or S position of the dihydropyridine ring; the dotted line in formula (xiii'~ indicates the presence of a double bond in either the 2 or 3 position of the dihydroquinoline ring; ~ , is the skeleton of a sugar molecule; niV is a positive integer equal to the total number of -OH
functions in the sugar molecule from which said skele-ton is derived; nv is a positive integer one less than the total number of -OH functions in the sugar molecule from which said skeleton is derived; each A in each of structures (xii'~, (xiii') and (xiv'~ can independently be hydroxy or D', D' being the residue of a centrally acting drug containing one reactive carboxyl functional group, said residue being characterized by the absence of a hydrogen atom from said carboxyl functional group in said drug; and each R4 in each of structures (x'~
and (xi'~ can independently be hydroxy, -u t~ .

~C~j or 0~, wherein the dotted line is defined as with structures (xii'~ and (xiii'); D' is defined as with structures (xii'~, (xiii~) and (xiv'); 21 is C1-C7 alkyl~ Cl-C7 haloalkyl or C7-Cl~ aralkyl; and the depicted carbonyl groupings can be attached at the 2, 3 or 4 position of the pyridinium or quinolinium ring or at the 1, 3 or 4 position of the isoquinolinium ring; with the proviso that at least one R4 in each of structures (x') and (xi ' ~ is OC ~

-oc ~3 or -OC~

wherein R1, the dotted lines and the position of the carbonyl-containing groupings are defined as above; and with the further proviso that when more than one of the R4 radicals in a given compound are the aforesaid carbonyl-containing groupings, then all such carbonyl-containing groupings in said compound are identical.
(3) For linkage to a drug having at least one -NH- functional group which is part of an amide or imide structure or at least one low pKa primary or secondary amine functional group, replacing a hydrogen atom from at least one of said functional groupings with one of the following ~DHC] groupings:

~C O CRH ~ X

Rl R3-COCH-- .
(k') 0 R (1 '~

~C O CH 2 CO C H-- , ~C OC, H-- , Rl I (n' ) (m' ) O
X COCH2COCH-- , R3-COCH-- , R 1 (O') (P') -57 ^

COCH ~ COC H--O R
(q' ) (r' ) r ~ ~COCHzCOlCH-- , (S ' ) wherein R is hydrogen, Cl-C7 alkyl, C3-C~ cycloalkyl, C1-C7 haloalkyl, furyl, phenyl, or phenyl substituted by one or more halo, lower alkyl, lower alkoxy~ carba-moyl, lower alkoxycarbonyl, lower alkanoyloxy, lowerhaloalkyl, mono(lower alkyl)carbamoyl, di(lower alkyl)carbamoyl, lower alkylthio, lower alkylsulfinyl or lower alkylsulfonyl; the dotted line in formulas (k'), (1') and (m') indicates the presence of a double bond in either the 4 or 5 position of the dihydropyri-dine ring; the dotted line in formulas (n'), (o') and (p') indicates the presence of a double bond in either the 2 or 3 position of the dihydroquinoline ring; R1 is Cl-C7 alkyl, Cl-C7 haloalkyl or C7-C10 aralkyl; ~3 is Cl to C3 alkylene; X is -CONR'R'', wherein R' and R'', which can be the same or different, are each H or Cl-C7 alkyl, or X is -CH=NOR''' wherein Q''' is H or C1-C7 alkyl; the carbonyl-containing groupings in formulas (k'~ and (m'~ and the X substituent in formula (1') can each be attached at the 2, 3 or 4 position of the dihy-dropyridine ring; the carbonyl-containing groupings in formulas (n'~ and (p') and the X substituent in formula (o'~ can each be attached at the 2, 3 or 4 position of the dihydroquinoline ring; and the carbonyl-containing groupings in formulas (q'~ and (s') and the X substi-tuent in formula (r') can each be attached at the 1, 3 or 4 position of the dihydroisoquinoline ring.
Drugs containing secondary or tertiary hydroxyl functional groups can be linked to any of the [DHC]
groupings (k') through (s') above in which the -CHO-R

portion is derived from an aldehyde RCH20 capable of reacting with said drug to form the corresponding hemi-acetal, e.g. chloral, acetaldehyde, formaldehyde orbenzaldehyde.
The following are especially preferred reduced, dihydropyridine forms of dihydropyridine ~ pyridinium salt redox carrier systems, also termed "chemical delivery systems" or "COS", for brain-targeted drug delivery which are contemplated for use in parenteral formulations with the selected cyclodextrin in accord with the present invention:

St~uct~re Che~lc~ me~bbre~l~ted h~me S~nth~ Phormocologlccl Us~

~c~1~ c~rC~ D~ 4-a I h3droiJrId I ne or O;-CDS I ~ o~ss4l ~ (opt Iner51c ~9;nt o ~t!~,t~)"
~,), (Isobuty;~lox~)phen~i;eth~;]]¦-dop~mlne-C052 Ex~ ple 4 ~s dop~mlne-CDS
c~rb~mo~l-1,4-dlh~aroo~rldlne t-l o o o ~l! nU ~ eth~ mlntc~rbon~l~lox~hphlen~l~-dop~mlne-CD53 Ex~ ple 115 ~s dop~mlne-CDSI ~
I dlh~dro-l-meth~1-3-p~rldlne- W
cllllltto tl c~rboxyl~te o Strutture Che~lc~l ~n~e Abbre~lcted ~-~e Synthes~s Phor ocologlcel Use o~
~ ~ J 17t-t(l,~-dlhrdro l _ethyl-3- testosterone-COSI U.S. P~tent ~o. ~ndrogen1c ~gent tn r l l I pyr1d1nylcerbonyl~o~y~ndrost-4- or T-COSI ~,~79,932 ~ c~ en-3-one E~-~ple 3h o~

r --Clll ~ ) cr~ [(3--c~rb~oyl 1 ,~ testosterone-COS2 80dor et el, es testosterone-COS
\tonn dlhydropyr1dlnyl)~c~tyl]o~y¦- 0~ T-CDS2 J. Phor~. S~l.
~ndrost-~-en-3-one (19C7J,75~1),29-35 ~ J ~
o ll l tt~s\,/~ a t ~ ~ / o S,S-dlphenyl-3-t(l _ ethyl-1 ,4 - phenytoln-CDSI Ele~ple 8 ~nt1con~ulsont ogent ' S ~ ~ U d1hydropyrldln-3 -yl~c~rbonylo~y- herelnbelo~ ~
O \tn10~ ~ ~ethyl]-2,~ 1d-rol1dlnedlone ~J~
~1 tnl ~
oo Strueture Che~lcol IbmeA~bre~l~ted h~me Srnthesls Phorm-cologk-l Use t~
c~ 3;t~;-e;rt_o~l;l ;~;-dlh~dro pl~enrto~n-C052 ~1 ple IS os ph~n~to1n-COS
'"~t ~ S,S-dlphen~1-2,~ ld~rol ~d~nedlone h~rtlnbeloll c~"~

t~ 11 y 0 ~3f~Uf~ 2 s ~s ~ h~ 7~ql-~0~ 12~h1~]- ~h~n~t ln-CDS~ t r t~t~t~ ~ ~r~'ttC~--CDSI

O ,_ tf2~1--CoDC11~3 ¢3' e~rboh7lip;op~lictrt~ mo~ - CACl-CDSI t7cbo~h 1~cot~5l~7 ~-~olrttt ~tnt t~

Str~ct~r~ Che~lc~ e ~bbre~cttd ~e Synthesls Phcn~cologlc-l Use C~C~ o{) h3~r ~rl~ 0~ CD52 h~ln~ CD51 \~~f~20C - C~lt~t~7t~2 1~ethyl-3-t2~-(2~ proprl) ~-lprolc ~cld-COSI Elcn~ole 61 ~ntlcon~uls~nt sgent t ~-dlh~drop~rldlne here1nbelo~

o cJ~

~t~ t-lln/C~ eht~o11D13~etho;;c~rb2r~ lprolc ~cl1-C052 h rellbeio~ s~ ~ol~rolc cld-tDS

t~l Structur- Che~lc~l h~e lbbre~1~ted hc~e S~nthesls ~hrr~colog1c~1 Use ~--t~2C~OC - C~C~c~C~thr; 3 C;rbo~P~')d nl''~n~'X~ lprolc ccld-C~53 h~ IPI 1~ lprolc ~cld-COS
c dlh~drop~rldlne ~C~C~CI~ Ic~c~ 1- eth~lj3-¦h-[tl ;etho~- trroslne-cDsl E~ple 29 neurotr~nS~ltttr ' phen~l)ethrl]¦c~rb~o~ - herelnbelo~ ~lno c1d d1h~drop~rldlne Clll o o Il îl c~c~)2 Phen~ th~ bSobut~r~lol~- t~rosln--C052 E~ ple 30 cs t~roslne-COS
I dlh~drop~r1dlne ~J~
c Structure the~lc~l h ~e Abbre~1~ted ~u~e S~ntbes1s Ph~n~colog k ~1 Use otll~
o~ ,s ~ ttll 4-d h~dro-1 _ th~1-3- ~ethlc~llln-CDS El--ple ~3 ~ntlblot1c, ~ntlb~cter101 t~ ~rrld1n~ 1corb~nrllo~r~nethrl here1n~elo~ ~gcnt ~e 9 tor br~1n oc~l 0~ ~25-(2-, -,6t) -3,3-d1~ethrl- ~bscesses ~nd neurosrph~l1s) ~-oxo-6- ¦2,6-~luetbo~r)ben2-~~f~ rl ~ldo~---thl~- -- u blcrclo-t3.2.0]he~t-ne-2-c~rbo~ te 1~1 [(l~l-d1h~ro-l-~eth~l-3- o~clllln-COS E~ple - cntlblotlc ~ntlbccterl-l o ~ pr~d~nrl)c~rbonrl~o~r~eth~l her~1nbelo~ cgent ~e 9 tor bre1n lo l25-~2~,5~,6C)]-3,1-dl ethrl- cbscesscs, neurosrph111s 6-~ ethrl-3-Ph-toc~toc ~ t~rbolc~ldo~-~-oso-~-thl~
2~blcrclot3.2 û~hept-ne-2-c-rbol~l t e ~O

Structuoe the~lcol llx~e ~bbrexloted h-~ Synth~ hcr~cologlcol Use t~ tn~ ~/ \ / '~
~25 12~ 1, 6~)~n;313Od1]~eth~1 h re1nb- o~ cntlblotle, cntl~ccter1 1 ta~ ~e ~ 7-oxo-6- ~phen~lccet~l)o~lno~
I l~,JI th1 ;1- ~;b1C,~C10~3 2 O]heptcne-1", , tt~ S ~ ~ [t~ dlhrdro-l_ethrl-l clox~clllln-CDS Exo~ple ~S cntlblotlc cntlb~cterlxl tY~ 0~ t25-~2O 5o 6~)~-6-t3-~2- herelnbelo~l g nt ~ ;9. ror br~ln th~orophen~l )-S_ethyl -~-COcl~ot~ lsox~zolecxrboxo~ldo~
O 0 ~ d~eth~l -7-OXO ~ th~ ~ 1 ~x~ ~eoblc~clot3.2.0~hept~ne-2-Co~box~l cte tbl Structur~ Che~lc~ e lbtrt~l~ted ~e S~nthesls Phor~cologlcol Use t ~ tt~ 4-dlhrdro-l-~eth~ dlcloxoclllln-C05 Ex~plo 46 ~ntlblotlc ~ntlb~cterl~l o~r dlnrl5e~6b~o)nlrllt3r-(2~6- here1ntelo~ 9~scess s neuros phllls) tl t~ d~c ~oroph~nrl~s~ ethrl~4 ~ Isoxrroler-.t~x- Ido]-3,3-toc~ot--~1 dl~ethrl~7~o~o~4~th1o~l~
t I ~,~ errblcrclo[3.2.0~heptone-2-c~rboJ~rl ~te o t¦h-t3-~10 11-dlhrdro-5H- dtslprr~lne-CDSI E~ple ~5 ontldeprets~nt I I I dlbenztb ~rrepln-S-rl)~prop~l- here1nbelo~ cn ¦ ~ot~ ~ - ~ H-~ethrl~lno~C~rbonrlo ~rl-th~th2t~ ~ ethrl 1,4-dlhrdro-1-~eth~1-3-p~rldlnecorboxrlote O~

Structure Ule~1c~ e ~bbre~l~te~ e S~nthesls Ph~r~cologlc~l Use o O~ o ~ 3;(1C 11 jdlh~lro-511- de~lpr-~ t-COS~ j s~l S~ ~ntl~epre~S~rl ~t~tC~2~t" 1;4-d1h~dro-l_eth~1-3-p~r1d1ne-Cll~

¢3 etho~r]t;rblnrj¦ 19u~dnih dtht ~ c~clo~lr-cDs El~ pl~ 1O] ~1~plel enc ph~l~tl~

1~

Structur~ Che~k~l ~bme~brevl~ted ll~me SrnthtslsPh~r~cologk~l Use o~
It ~ cll p trl~luOroth~1d~l) 5 -P~v~iorl- CDS or TET-CrDS ~ h~ ple 107 ntlvlr~ ntl-herpetlc tl~

O /~ ~3 3~ o-3;-~o~1-S;~ h~ o u~ cns E ~ O ~ r hu~o "~ D~

0~e~;r on1io~ )clC1 cr ttl-CChU-Cos Int~ t no~r Drllg ntltLl-Or ;9ent Str~ct~r~ Che~lc~l h~ tbre~l-ted h~e S~nthes1s ~her ~cologlc~l Use t,~ f,/ ~ ~ r~ f~t~ ]~tb~r~r~ C~ t~ lor~ c~l CDsl 1 5" ,~ ~t~t~C r;

c;rb~O~ -d~h3t1ndol1l)eth~l~- tr~pt~lne-CDS ru Oes1 n ~nd c ~ ~ u; tor el~-cr~ ~Ig~6~, ~potent1~tes or I _, 051~6~ ont~oon1~es serotonln) S ~ I ~c>

~C
~o 9-tluoro-tl~,17-dlh~dro~-16O- de~eth~sone-CDS E~ 4 1e 118 ont11ntle~n~tor~
~t~ ~eth~1-21-¦t¦l-~eth~l-1,~-d1h~dro- herelnbelo~ ~gent ( I l I 1 p~r1dln-3-~l)c~rbon~l~o~¦pregn~
1,~-d1ene-3,20-d1One C~
o~ ~9 ~, , .~ V . o - ~ ~ .
, _ . .. . . .

_ C _ .

, _ ~
.,. ". ~.
., . _ V' ~
~ .,., ~ C _, V~ V-Y ., Vl _ ~
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.. C
r . .
r_ --e o _ ~ o . O _ ~ ~ _ , r~ o =~
~ ,, _, ~ _ O
_ _ , _ ~ _ o ~ _ . , ~, _ ,.~
_ ~r c ~ o _ '`o __ o ~ ~ _~ _~

5tructure C~e~lt~ me ~bbrevl~ted ~e Synthesls Phor~cologlc~l U--c~l ¦ ~ 3-h~dro~-170-~¦1-meth~ - estr-dlol-CnS U S, Potent ho estrogen (e.9 tor control ~r~ ~ ¦ d1hydrop~rld1n-3-yl)cerbDon~l]- or E2-COS ~,617 298, o~ rDu-sl ~J14tO~s, tor t~ o~estro-1,3,5~10~-tr1ene E~mpie Il ~enstru~l d1sorders such ~s - d~ -Drrlco, s o contr~ceptl~e co~ponent, tor ~e1ght control, tor prost~te c~ncer, for ~le se~uol d~stunct1On) Il ,~CN~
a c ~
17~-([(1-~eth 1-1 ~-dlhydrop~rldln- etb1sterone-CDS ~,re~ster e ol, progestln-~ 3 ~I)c~rbonrl~o~¦pregn-~-en-20-~n e rch 1 90S), _J

o -~5). Zlo- ôS
ocl~
~

~ 13-ethyl-17~-[t(l-meth~l-1,~- norgestrel-C05 ~e~ster e 1, proges t1n~
1 J I dlhydropyr1dln-3-yl)ccrbon~l]o~¦- urm~ceut ccl ~s noreth~n drone-CDS
18,19-dlrorpreD ~-ene-20-~n-3-one seereh ~ 906), CX~
5), ~D- 85 Structure Che~lc~ e ~bbre~l~ttd h~e Synthesls Ph~rm~cologlc~l Use -' I 3 $(19) tr~er-~ on~ E 5'7 298 ~ ~ ~ ';''-~ 5 1", 17~ meth~ dlh~dro-3- estr~dlol 3- U S P~tent ho. estrogen-i 3 S¦lD)-trlen-3-ol meth~l ether-COS El-~pie 6 ~S estr~dlol-CDS
3-meth~l ether 1 3 -S(l:~-trlelr~17l] ;~'5 " '~ es~r~dlol bls-CDS h r 1Dbelo~ s estr~;lol-C:S C~
~ ~O

Stru~ture Chemlcel h~mt ~bbrt~l~ttd h~me S~nthesls Ph-nu cologlc-l Use ~ ~ 3-(phen~ rbon~10~ 17~ 1[(1- estr~dlol E~mple 75 estrogen-L J ' ~, meth~ -d1hrdrop~rldln-3-~1)- benlo~te-CnS herelnbelo~ ~s estr~dlol-tDS
c~rbon~l]o~¦estre-l 3 S(10)-trlene ~C~ , 17~-¦ttl-meth 1-1 ~-d1h~drop~rldln- noretb~nodrtl-CDS ~rom noreth~no- progestln-~t - a 3-~1)t~rbon~l~o~ 9 rD~re, -5~10)- dr-l enelogousl~ es norethlndrone-CDS
en-20-~n-1-one o ethods of w r~c ut c~l e~re ~ 9~6 5) Z ~- 85;
so U.~. -tent ~o. 1 5-0 56~

W

9 ",t~l W
l.,t ~) ~
3-methox~-l7~-ltl-metny~ - mestr~nol-CDS ~rom ~estrenol estrogen-d1b~drooyrldln-3-~11cerbon~1 ]o~r ¦- enelogousl~ to en estr-dlol-COS `5~
~ 19 nor-17~-pregne-1 3 5~10)-trlen- method5 o~ Bre~ster CXD
r ¦l 1 20-~ne et el her~cceut1cel ~'5 " ' ~1986) 53 Petent o. 1 617 298 Structure Che~e~l N~me Abbre~l~ted N3me Synthes1s ~horm~colog k ~1 Us-c~ methyl-3-tN-(2-¦1-(p-chloro- Ind meth~c~n-CDS E~mple 97 ~ntllnfl~n~tory ~gent '~1 ben~o~l~-S-metholy-2-meth~1-3- here1nbelo~
Indol~ ceto~r ~eth~l)c-rb-~o~l]-1 4-dlh~drop~rldlne C112~ ~ACy~
eth~1-3-¦h-[2-(6-~etho~ - n~pro el COS E~nple 96 ~ntllnrl~ to~
~eth~l-2-n~phth~len~l~cetor~ethrl]- herelnbelo~ ~gent ~l c~rb~morl-l ~-dlh~drop~rldlne I~ n t C ~t 2~ Cl~ Q o A l-~ethyl-3-(N- l-t~ tbls(2- chlor-mbuc11-CD52 E~mple 82 s chlor~mbucll-COS
J ~ chloroeth~l)]~lno¦phen~l)butono~l- here1nbelo~ ~~
o~]c~clohe~l c~rb~mo~l)-l 4-d1h~drop~rldlne CX~
~1 Structure Che~lc~l H~me Abbrt~l~ted H~me S~nthesls Ch~rm~tologlc-l Use c lazaz clchza2~3-~cl~zl~2~c~ chloroeth~ m~no~ hen~;¦but~no~l- chlor~bucll-CO53 E~mple 85 ~s tnlor~bucll-CDS
Ch~ o~]prop~l~)c~rb~lmo~l]-l,~-d~h~dro-C~zCI~2 Lla~/ ~(a~ 2~ ~hloro~ths~ ph~ t ~ (2; chlorc~b~cll-CDS E ~ ple ~2D ss chlorc~.cll-CDS

~-c (az~3 fh2C112C~
~ \~h2~hZt I
chloroeth~i)];mlno~jphen;l)but~noyl- chlor~mbucll-CO55 Elsmjole 101 ~s chlor~bucll-COS
C~12~S~ o~ cyclohe~ meth~l)c~rb~mo~l]- ere nbelo~
-dlh~drop~r~dlne E,., ~

Structure Che~le~l N~t Abbre~lcted N~eSynthesl~ ~hcr~ccolog1cCI Uhe zr~2 ~ - ~ zt~2~ h-(2-~luoroeth~l)^N'-~2-(1 4- FENU-COS El~ple 127 ~nt1c~ncer ¦1 no dlh~dro~ ethrl-3-prrldlne- herelnt~tlo~ cntltu~or ~gent c~rbonylo~y)eth~ N-nltrosoure~

~ ~ ~o~a2tl ~-(2-chloroethyll-N'-[2-(1 ~- HENU-C~SE~c~ple 121 ~ntlccncer I 11 1 lo d1hrdro-l-~ethrl-3-p~r1d1ne- here1nbelo~ ~nt1tu~or egent ~I c~rbonr10~r)~thrl~
r n1trosoure~
e-l, _ ~ ~ f 3 (1 ~-d1hrdro-1-~ethrl-3- S-fU-C~S~E~ple 135 ~nt1c~ncer I lî Prr1d1nrlc~rbon~lo~y~ethyll-s- here1nbelo~ ~ntltu~or cgent ~J~
j O~ ~ tluorour~cll CJ~
cl ~ ~
~0 U

.

, ~

Z

_ .
~ .
_ .

.._ The cyclodextrins contemplated for use herein are hydroxypropyl, hydroxyethyl, glucosyl, maltosyl and maltotriosyl derivatives of B-cyclodextrin and the corresponding derivatives of y-cyclodextrin. The hydroxyalkyl groupings may contain one or more hydroxyl groups, e.g. hydroxypropyl, dihydroxypropyl and the l~ke. The glucosyl, maltosyl and maltotriosyl derivatives may contain one or more sugar residues, e.g. glucosyl or diglucosyl, maltosyl or dimaltosyl.
Various mixtures of the cyclodextrin derivatives may be used as well, e.g. a mixture of maltosyl and dimaltosyl derivatives. Specific cyclodextrin derivatives for use herein include hydroxypropyl-B-cyclodextrin (HPCD or HPBCD), hydroxyethyl-B-cyclodextrin (HEBCD), hydroxypropyl-Y-cyclodextrin (HPGCD), hydroxyethyl-Y-cyclodextrin (HEGCD), dihydroxypropyl-B-cyclodextrin (2HPBCD), glucosyl-B-cyclodextrin (Gl-B-CD or G1BCD), diglucosyl-B-cyclodextrin (2Gl-B-CD or 2GlBCD~, maltosyl-B-cyclodextrin (G2-B-CD or G2BCD), maltosyl-Y-cyclodextrin (G2-Y-CD or G2GCD), maltotriosyl-B-cyclodextrin (G3-B-CD or G3BCD), maltotriosyl-Y-cyclodextrin (G3-r-CD or G3GCD) and dimaltosyl-B-cyclodextrin (2G2-B-CD or 2G2BCD), and mixtures thereof such as maltosyl-B-cyclodextrin/dimaltosyl-B-cyclodextrin.
~ ydroxypropyl-B-c~clodextrin for use in the methods of the present invention is commercially available. Alternatively, it may be prepared by known methods, especially by use of the optimized procedure of Pitha et al, ~nternational Journal of Pharmaceutics, 29, 73-82 (1986). The following is a typical procedure using the Pitha et al method:

31 9 of sodium hydroxide were dissolved in 250 mL
of water. Then, 100 g of B-cyclodextrin were added and the solvent was warmed to effect solution. The flask was cooled and 50 mL of propylene oxide were added.
The flask was fitted with a dry ice/acetone condenser during the addition. The solution was allowed to come to room temperature and was stirred for 72 hours. The solution was then neutralized with concentrated hydro-chloric acid and diluted with water. The solvent was removed in vacuo, leaving a syrup which was taken up in ethanol. After stirring for 30 minutes at room temperature, the sodium chloride produced was removed by filtration. The filter cake was washed with ethanol and the combined ethanol layers were reduced in vacuo. The residue was dissolved in water and dialyzed in cellulose acetate (#7, 38 mm 4.6 mL/cm, molecular weight cut off = 100n, Fisher Scientific). After 5 hours at 0C, the solution was removed from the dialysis tubing and freeze-dried. The resulting solid was suspended in acetone and stirred overnight. The filtered solid was resuspended in acetone and stirred for 24 hours. The solid was collected by filtration and dissolved in 200 mL of water and then lyophil-ized. 75 grams of purified hydroxypropyl-B-cyclo-dextrin were obtained. The degree of substitution wascalculated by NMR and by comparison with an authentic sample.
In forming a complex with E2-CDS, a 50X solution (w/w) of 2-hydroxypropyl-B-cyclodextrin (HPC~) was made in distilled water. An excess of E2-CDS was added and the solution then was purged with helium. The result-ing suspension was then sonicated for 30 minutes~ fil-tered through a glass filter (ASTM 10-lSM, Pyrex No.
,.

m~

36060) and freeze-dried overnight. ~est results were obtained by hard-freezing the aqueous solution of the E2-CDS/HPCD complex for at least 10 hours before lyophilization. The degree of complex formation was determined by dissolving a small amount of the dry complex in methanol and then analyzing by high pressure liquid chromatography (HPLC). The degree of complexation was found to vary between ~n-40 mg/g and the solubility of the complex was determined to be 2.2x104 rrlg/L, The Pitha et al method for preparation of HPCD by condensation of propylene oxide with B-cyclodextrin in alkaline aqueous solution unfortunately suffers from disadvantages, particularly in purification of the lS product. After completion of the condensation, the reaction mixture is neutralized with hydrochloric acid, water is evaporated under vacuum and the syrupy residue is dissolved in ethanol to precipitate sodium chloride, the main by-product of the reaction. After filtration, ethanol is evaporated under vacuum and the residue is dissolved in water and dtalyzed to remove the remaining sodium chloride and polymertzation products of propylene oxide. During dialysis, part of the hydroxy-propyl-B-cyclodextrin goes through the membrane and is lost. The dialysate is then freeze-dried, twice stirred in acetone and washed to remove the remaining polymerization products. Finally, hydroxypropyl-B-cyclodextrin is freeze-dried again. The second freeze-drying is necessary because the product after washing with acetone is not homogeneous.

~ 336498 To overcome these difficulties with the Pitha et al process, a new method has been developed by Maciej Smulkowski of the University of Florida, Gainesville, Florida for the synthesis of HPCD. This new method involves removal of sodium hydroxide from the reaction mixture by an ion exchange resin (H+); as a result, several time-consuming steps of Pitha et al's puri-fication can be avoided. Moreover, the amount of sodium hydroxide used by Pitha et al (7 equivalents for one of ~-cyclodextrin) can be decreased to 2 equivalents of sodium hydroxide per cyclodextrin molecule, and still produce a product with the appro-priate NMR and optical rotation.
According to the new method, B-cyclodextrin is first condensed with propylene oxide in alkaline solu-tion, sodium hydroxide is removed on an ion exchange column (~owex 50W-X8, H+ form), the eluate is eva-~-~ porated under vacuum to one-half of the original volume, the remaining solution is freeze-dried, the resulting white solid is washed with acetone and freeze-dried again, then subjected to grinding and sieving. Possible modifications of this method include: (1) use of the ionic exchange resin for neutralization in the react~on flask, wlth f~ltration of the resin and washing on the filter funnel; (2) use of calcium, magnesium, lithium or potassium hydroxide to dissolve the cyclodextrin; (3) removal of hydroxides after the reaction by saturating the reaction mixture with carbon dioxide or neutralization with sulfuric acid in place of the ion exchange resin; (4) use of even less sodium hydroxide (between 1 and 2 equi-valents); and (5) elimination of the second freeze-drying, r~Q m~rlC

The following is a typical procedure using the new, improved method:
50 9 of ~-cyclodextrin was dissolved in a solution of 3.53 9 of sodium hydroxide in 75 mL of water and treated with 29 mL of propylene oxide at 0C. The reaction mixture was maintained for 5 hours at that temperature, then was kept at room temperature for 42 hours. At the end of that time, the reaction mixture was passed through the Oowex 50W-X8 column (H+ form), the column was washed with water and the eluate was evaporated under vacuum to a volume of 100 mL, then freeze-dried. The resulting white solid was washed with acetone to give 51 9 of HPCD, with the same degree of substitution (4.7) and ~MR as the HPCO prepared by the Pttha et al method. Qesidue on ignition was o.nx. Optical rotation also was identical to that of the Pitha et al product.
Condensation of 25 9 of ~-cyclodextrin using 7.71 9 of sodium hydroxide gave similar results.
A further improvement in the new, improved HPCD
synthesis utilizes activated carbon for purification of the solution prtor to the last freeze-drying. Thus, when the aqueous solution from the Dowex 50 ionic exchange column was treated with activated carbon, most of the polymerization products were removed without loss of HPCD, and the filtrate after only one washing with ethyl acetate was ready for final freeze-drying.
In this way, only one freeze-drying was required.
Crystallization of the final product instead of freeze-drying is also possible, at least on a small scale.
The product from the modified new process (usingactivated carbon) appears to be superior to that of the original new process and the Pttha et al process.
First, the product is snow white and produces a color-less aqueous solution, whereas solutions of the earlier products were yellow. Secondly, the product is not oily, which may be due to removal of more highly sub-stituted, less soluble, oily cyclodextrins.
HPCD can be prepared in varying degrees of sub-stitution, such as 5 or 7. Typically, the foregoing procedure is used to produce HPCD (ASDS 7). rhe mass spectra for the isomeric misture of HPCD centers around 7 degrees of substitution. This spectra is obtained by "softly" ionizing the sample using fast atom bombardment. The generated spectra is similar to those previously reported (obtained by Californium-252 plasma desorption) in both the symmetry of the isomeric distribution and the numerical spread of the isomers formed.
Hydroxyethyl-B-cyclodextrin (HE8CD) can be pre-pared analogously to HPCD, utilizing the improved procedure detailed above but substituting an equivalent quantity of ethylene oxide for the propylene oxide there employed.
The synthesis of 2-hydroxypropyl-r-cyclodextrin (HPGCD) similarly uses the same basic procedure as for HPCD, substituting y-cyclodextrin for the B-cyclo-dextrin starttng material. However, because y-cyclo-dextrin contains eight glucose residues comDared toseven for B-cyclodextrin, the amount of propylene oxide used can be reduced in order to lower the degree of substitution. ~Jse of 0.75 mole of propylene oxide per 0.077 mole of y-cyclodextrin (~ 20% excess considering 8 OH grouDS~ affords HPGCD with a degree of substitu-tion of 8, while use of 0.56 mole of propylene oxide (~ lOX less than equivalent~ gives a deqree of sub-stitution of about 7.
Hydroxyethyl-r-cyclodextrin (HEGCD) can be pre-pared similarly to HPGCD as described in the precedingparagraph, simply using an equivalent quantity of ethylene oxide in place of the propylene oxide.
Thus, the hydroxyalkyl cyclodextrins intended for use herein can be prepared by procedures described by Pitha et al or variations thereof. Obtained by these procedures, the cyclodextrins are intrinsically amorphous mixtures. The importance of the amorphous nature of the cyclodextrins is described by Pitha et al, J. Pharm. Sci., Vol. 74, No. 9, September 1985, 987-990. The advantages of the amorphous nature of these materials are more pronounced at higher concentrations of cyclodextrin.
The other cyclodextrins intended for use in the present invention, i.e. the glucosyl, maltosyl and maltotriosyl derivatives of ~- and r-cyclodextrin, are branched cyclodextrins which are highly soluble in water as compared to the parent cyclodextrins. These branched cyclodextrins can be produced by microbiolo-gical processes from the parent cyclodextrins.
Glucosyl-B-cyclodextrins can be obtained from the mother liquor of a large-scale B-cyclodextrin synthesis with Bacillus ohbensis cyclomaltodextrin glucanotransferase; see Koizumi et al, Chem. Pharm.
Bull., 35 (8), 3413-341B (1987) and reference cited therein. Maltosyl and maltotriosyl B- and r-cyclodextrins can be prepared from the parent cyclodextrin and maltose or maltotriose through the reverse action of Pseudomonas isoamylase or Klebsiella -85- l 3 3 6 4 9 8 aerogenes pullulanase, while glucosyl-r-cyclodextrin can be prepared by enzymatic hydrolysis of maltosyl-y-cyclodextrin; see Okada et al, Chem. Pharm. Bull., 36 (6), 2176-2135 (1988) and references cited therein.
The preparation of maltosyl-~-cyclodextrin by reacting maltose with B-cyclodextrin in the presence of pullulanase is also described in Japanese Kokai 61-287902, published December 1~, 1986, an~ Japanese Kokai 61-197602, published September 1, 1986. A mixture of ~altosyl-~-cyclodextrin and various dimaltosyl-~-cyclodextrins may be conveniently e~ployed, e.g.
~SOELEATrM of Ensuiko Sugar Co., Ltd., Yokohama, Japan.
The development of a carrier-mediated dihydro-pyrid1ne + pyridinium salt redox system (which, in the dihydropyridine form, is also termed a chemical deli-very system or C~S) has resulted in the enhanced and/or sustained delivery of a variety of drugs to the central nervous system. While the physiochemical properties of the CDS are optimized for brain-uptake and retention, they are often incompatible with aqueous formula-tions. A salient example is E2-CDS, a C~S based on estradiol. This dihydronicotinate passes the B~8 and is oxidized to the corresponding quaternary salt, E2~+. The sustained levels of E2Q+ thus produced then slowly release estradiol, which exerts profound central estrogenic effects. These effects include LH-suppression in ovariectomized rats and a reversible suppression of cyclicity in intact female rats and are exerted for prolonged periods. The E2-CDS is highly lipophilic and only poorly water soluble (0.2 ~g/mL).
This requires that E2-CDS be administered in water-miscible organic solvents such as dimethylsulfoxide (DMSO) or dimethylacetamide (nMA). ~hile this -86- l 336498 procedure is not inappropriate for laboratory animal studies, it is clearly inadequate for human use for reasons enumerated hereinabove. The development of aqueous formulation of E2-CDS was therefore lnvestigated. Criteria for this formulation include that it have minimal toxicity, that it be e~uivalent with E2-CDS in ~SO or OMA in delivering E2Q+ to the brain and that the technology developed be applicable to other dihydropyridine ~ pyridinium salt redox systems.

EXPERl~E~rAL SECTlON
~aterials: 3-Hydroxy-17B-~(1-methyl-1,4-dihydropyri-din-3-yl)carbonyl]oxyestra-1,3,5(10)-triene (E2-CDS), l-methyl-3-~{N-{B-~3,4-bis(pivalyloxy)phenyl]ethyl~-carbonyl~}-1,4-dihydropyridine (D~-CDS), 17B-[(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)oxy]androst-4-en-3-one (T-CDS~), 1-methyl-3-N-[3-(benzyloxycarbonyl~-propyl]carbamoyl-1,4-dihydropyridine (6~BA-CDSl), 1-methyl-3-{[2-(9-guanylmethoxy)ethoxy]carbonyl~-1,4-dihydropyridine (~CV-CDS) and 17B-~(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy~-19-norpregn-4-en-20-yn-3-one (~-CDS) were synthesized according to published procedures. 2-Hydroxypropyl-g-cyclodextrin (statistical degree of substitution = 5.1 or 7) (HPCD) ~as prepared according to the method of Pitha et al.
Other cyclodextrins (~,B or ~) were obtained from Aldrich Chemical Co. and other steroids (estradiol, estradiol 17-valerate, estriol, estrone, estradiol 3-methyl ether and testosterone 17-propionate), were purchased from Sigma Chemical Co. All prepared compounds were fully characterized by spectroscopic and microcombustion analysis (Atlantic ~icrolabs) prior to study. Mass spectroscopic studies were performed on a Kratos ~S80RFA double-focusing instrument fitted with a fast atom gun. Cyclodextrin mixtures were analyzed by fast atom bombardment of the samples prepared in a glycerol matrix. Degrees of substitution were deter-mined from the isomeric mass distribution. Nuclear magnetic resonance spectra were obtained on a Varian EM360 60 ~Hz spectrometer. Values were recorded relative to an internal standard t3-(trimethylsilyl~-propionic 2,2,3,3-d4 acid, sodium salt, ~OS] and all samples were run in n20. rhe degree of substitution was calculated by comparing the integrated area attributed to the anomeric hydrogen compared to that of the hydroxypropyl functionality.

Effect of Solub~liz~ng Agents: An excess of E2-CDS was sonicated with an aqueous solution of the appropriate solubilizing agent for 30 minutes. The suspension was then centrifuged, filtered through 0.45 ~m polyvinyl-idene difluoride (Millex-HV4, ~illipore2~ membranes and analyzed by HPLC. For studies with 2-hydroxypropyl-~-cyclodextrin, an excess of E2-CDS was added to different concentrations (X w/v) of HPCD and the solu-btlity (mg/mL) was determined spectroscop1cally (UV =
36n nm, ~ 3 6487 in methanol). ~n estimation of the bulk equilibrium constant was obtained by correlating the millimolarity of E2-CDS solubilized and the millimolarity of the cyclodextrin added. This latter value was calculated using the average molecular weight of the isomeric mixture determined by mass spectro-scopy. The solubilizing effect of a 50X w/w solutionof HPCD was also examined for a series of steroids and dihydropyridines (CDS). These studies were carried out in a similar manner to those previously described.

Preparation of Solid Complexes: An excess of E2-CDS or other CDS was added to a sn~ w/w solution of HPCD. The suspension was sonicated for 30 minutes, filtered through 0.45 ~m PVDF membranes and freeze-dried. The degree of incorporation was determined either spectro-photometrically or by HPLC. In some cases, the effect of solubilizing agents on the degree of incorporation was examined. This involved adding small amounts of polyoxyethylene 20 cetyl ether (Brij), polyoxyethylene sorbitan monooleate (Tween 80) or ethanol to the aqueous solution prior to lyophilization.

Analyt~cal ~ethodology: In determining concentrations spectrophotometrically, a Cary 219 (Varian) or an HP
8451A Diode Array (Hewlett Packard) spectrophotometer was used. Standard curves were prepared in methanol and gave correlation coefficients greater than 0.999.
For the CDS, the wavelength monitored was 360 nm while for estrogen 220 nm was used.
The HPLC system consisted of either an Autochrom ~500 pump fitted with a Rheodyne injector or a Perkin-Elmer Series 4 pump, a Kratos Spectroflow 757 variable wavelength detector and either a Beckman recorder or an LCI-100 integrator (Perkin-Elmer). Separation was achieved on an Analytical Sciences, Inc. (ASI) 10 ~m particle size, C18 reversed phase 3n cm x 3.9 mm i.d.
analytical column. The flow rate was 1 mL/min, the compounds were detected at 360 nm and in all determina-tions the temperature was ambient. A mobile phasecontaining 82 :1:1 :16 (acetonitrile: tetrahydrofuran:

acetic actd: H20) eluted the E2-COS at 4.4 min, the DA-CDS at 4.4 min, the T-CDS1 at 6.8 min and the ~-CDS at 5.2 min. For the GABA-CDS1, a mobile phase consisting of 50~ 48 of the same components was required. The retention time was 5.2 min. Other compounds were assayed spectrophotometrically.

~ntmal Studies: Conscious, restrained Sprague-Dawley rats (female, BW = 200 9) were given either 15 mg/kg E2-CDS in DMSO or 5 mg/kg of E2-CDS complex in ~PCD
(E2-CDS-HPCD) in water by intravenous injection (tail vetn). At various times after the administration, animals were sacrificed and trunk blood and organs collected. The organs were then weighed, homogenized tn water and deproteinized with cold acetonitrile. The organ homogenates were centrifuged and the supernatant analyzed for E2Q+ and E2-CDS using a precolumn enrichment technique. the details of which are given hereinbelow.

RESULTS A~D D~SCUSSIO~
~s dtscussed hereinabove, cyclodextrins have been used to increase the water solubility of a number of drugs, including sterotds. These cyclic oligomers contain vartous numbers of 3-1,4-linked glucose untts. The number of these units (~ = six, B = seven, ~ = eight) determine the size of a cone-like cavity wh~ch is amenable to inclusion by many drugs. The stability of the complex formed depends on the fit of the drug into the cyclodextrin and the cyclodextrin concentration. Unfortunately, the cyclodextrin best sutted for complexation with steroids, i.e. B-cyclodex-trtn, is poorly water-soluble. This property is - 9 o -dertved from the high degree of hydrogen bonding which occurs in the crystal lattice. To add to the problem, B-cyclodextrin is known to cause nephrosis in rats, a toxicity which results, at least partially, from its poor water solubility. In any case, little change in the aqueous solubility of E2-CDS was observed when it was equilibrated with various solutions of either , B
or ~-cyclodextrin. As illustrated in Table I, concentrations of a-cyclodextrin up to 50 mm increased the aqueous solubility of E2-CDS only 25-fold while B
and y-cyclodextrin increase the solubility of the CDS
135 and 110-fold respectively. rhe relationship between the aqueous solubility of E2-CDS and the concentration of the unsubstituted cyclodextrins was not linear, a situation which is also observed in the case of the parent steroid. In any case, the limited water solubility and the relatively poor complexation provided by a-, B- or y-cyclodextrin are unsuitable for pharmaceuttcal exploitation. The toxicity of B-cyclo-dextrin underscores this assessment.

-g 1 - I 3 3 6 4 9 ~

rABLE I
iEFFECr OF VARIOUS C~CLOOEXTRI~S 0~ THE ~ATER SOLU8~LrT~

Conc. of Cyclo- ~aximum Cyclodextrin at dextrin Conc. Ran~e Solubility ~ax. Solubility n (m~ or Xw~v) (mg/mL) (mM or Xw/v) None - 0.0002 Alpha ( a)5-50 mM n.oos 5~ mM 7 Beta (B)5-15 mM 0.027 1n mM 5 Gamma (y)5-50 mM 0.022 10 m~ 5 HPCD0.78-62.5 (7 AS~S)~w/v 30.19 62.5 ~w/v 9 HPCD 1-62.5 (5.1 ~SDS)Xw/v 35.12 ~2.5 ~w/v 5 Several efforts have been made to increase the aqueous solubility and, therefore, usefulness of cyclo-dextrins. Various methylated derivatives have been described but, in general, the acute toxicity of the modified compound is greater than that of the parent.
Qecently, an amorphous cyclodextrin composition was obtained by hydroxypropylation of B-cyclodextrin. The product, 2-hydroxypropyl-B-cyclodextrin (~PCD), is a mixture of isomers which can be characterized by the average statistical degree of substitution (~SDS).
Either NMR or mass spectroscopy can be used to deter-mine this value. These highly water soluble mixtures were shown by Pitha et al to dramatically increase the solubility of a number of compounds including gonadal steroids. In addition, preliminary toxicity studies -92- l 336498 have shown few, if any, harmful effects after either oral or intravenous administration.
HPCn (ASDS 5.1 or 7) was prepared according to the method of Pitha et al. The mass spectra for the isomeric mixture of HPCn centered around 7 degrees of substitution. This spectra was obtained by "softly"
ionizing the sample using fast atom bombardment. The generated spectra was similar to those previously reported (obtained by Californium-252 plasma desorp-tion) in both the symmetry of the isomeric distributionand the numerical spread of the isomers formed. In the cited example, as in the 5.1 ASDS case, no underiva-tized (toxic) B-cyclodextrin was detected.
In applying this HPCD composition to E2-CDS, HPCD
with low ASDS's was selected. ~s the degree of substitution increases, not only does the complexing propensity of the cyclodextrin decrease, presumably due to steric interactions, but the surface activity of the complex increases. This is undesirable since, in general, as the surface activity increases, so does the tendency of the material to cause hemolysis. Both the 5.1 and 7 ASDS HPCD had a profound effect on the solu-bility of E2-COS. In the 7 ~SDS case, a linear increase (r = O.99S) in the solubility of E2-CDS was evident as the concentration of HPCn was increased. At 62.5X w/v, 30.2 mg/mL could be solubilized. In the 5.1 ASDS material, 35 mg/ml of E2-CDS could be solubilized at 62.5X w/v. The lower ASDS material gave a 15X
increase in incorporation. These data reflect an increase in solubility of five orders of magnitude (150,000-fold) over the solubility of E2-CDS in water (Table 1). Plotting the data obtained from the 7 ASDS
study as millimolarity of E2-CDS solubilized versus the millimolarity of HPCD added (based on the average molecular weight of the mixture) gave a line with a slope of n.2. rhis is an estimation of the bulk stability of the cyclodextrin complex and compares reasonably with other systems.
These solutions could be freeze-dried giving a solid complex. A 50S w/w solution of HPCD gave a solid containing 37 mg E2-CDS/gm complex. The complex was stable dS a dry powder and could be easily reconsti-tute~ with water. ~n these manipulations, it was important to maintain the HPCD component greater than 20t w/v. ~elow this level, precipitation would occur. Several attempts were made to increase the degree of incorporation of the complex by adding various agents such as ~rij (0.7~ w/w), Tween ~0 (0.
w/w) or ethanol (10~ v/v). While the addition of Brij increased the degree of incorporation to 189 mg/g, the complex was not stable, falling to 42 mg/g in 12 days. The other agents had only modest effects. The upper limit for a stable complex, therefore, appeared to be approximately 40 mg/g under these circumstances.
Since an inclusion complex is formed between E2-CDS and the various components of the cyclodextrin mixture, it is possible that some portion of the E2-CDS
would not rapidly dissociate, thus lowering the biolo-gically available concentration of E2-CDS. To investi-gate this possibility, the ability of the HPC0 (5.1 ASOS) formulation of E2-C~S (E2-CDS-HPCD) to deliver E2Q~ to the brain was measured and compared with the ~94- 1 3 3 6 4 9 8 delivery of E2Q~ when E2-CDS was administered in DMSO. ~rain concentrations of E2Q~ were measured after systemic administration of either 15 mg/kg E2-CDS in DMSO or 5 mg/kg E2-CDS in aqueous HPCD. When the difference in dose is accounted for, i.e. the data is presented as ~ dose/g, no significant difference exists between brain levels of E2Q+ after E2-CDS
administration in DMSO or E2-CDS-HPCD in an aqueous media, although the latter produce data which are strikingly more consistent and less variable.
Interestingly, the levels of E2~ in the lung are lower after E2-CDS-HPCO administration. One explanation for this is that when E2-CDS is given in a water miscible solvent such as D~SO, there may be some tendency for the highly water insoluble E2-CDS to precipitate.
~fter a bolus i.v. injection, the aqueous, ionic environment of the lung may provide a suitahle site for this precipitation. The lower levels obtained in the lung after E2-CDS-HPCD administrations reflect not only the higher water solubility of the complex but may also indicate something of its in vivo dissociation constant. Quite surprisingly, this dissociation appears to be fast enough so not as to alter the distribution of E2-CDS in the C~S, but slow enough to allow pulmonary transit (or transit from other organs such as the liver) without significant precipitation.
In addition, the values for various organ concentra-tions are far less variable after E2-CDS-HPCD
administration, which may be explained by the higher water solubility of the complex and its lower tendency to precipitate. Ongoing pharmacological studies 1 3364~8 corroborate the effectiveness of the E2-CDS-HPCD
formulation in brain-selective delivery.
The effect of a 50X w/w solution of HPCD on the solubility of a number of steroids and other CDS is given in Table II.

TABLE II
SOLUBILIT~ OF VARIOUS STEROIDS AND VARIOUS DRU6 CHE~ICAL DELIVERr S~STE~S IN A 50t ~/~ SOLUTION Of 2-HYDROX~PROPrL-~-C~CLODEXTRIN (ASDS 5.1) AND THE A~OUNT
OF DRU6 INCORPORATED IN THE FREE~E-ORIED CO~PLEX

Solubi1ity Amount of Drug (mg/mL) in in Dry Complex Drug 50X w/w HPCD (mg/g) 15 Estradiol 25 Estriol 40 Estrone 9.52 Estradiol 3-Methyl Ether 30 20 Estradiol 17-Valerate 13.8 23.5 Testosterone 38 SolubilityAmount of Drug (mgtmL) inin Ory Complex Drug 50X w/w HPCD(mg/g) Testosterone 17-Propionate 38 65.6 Testosterone-COS
(T-COS1) 17.1 29.0 Norethindrone 68 Norethindrone-CDS
(~-CDS) 0.35 0.6 ACV-COS 14.9 25 Thus, E2-CDS and several other CDS were success-fully solubilized with HPCD, although this is not universal: norethindrone-COS, for example, was not readily solubilized. The best solubilization of E2-CDS
occurred in an aqueous solution of HPCD, ASDS 5.1 or 7. These complexes could be freeze-dried and were stable. They were easily reconstituted in water so long as the cyclodextrin component was at least 20Z
w/v. This formulation was equivalent with E2-CDS
administered in DMSO in delivering E2-Q+ to the brain of rats. In addition, the formulation significantly reduced the lung concentratlons of E2Q+. Data available at present indicates this excipient is less 97_ 1 33 6~98 toxic. easily co~pressed into tablets. rapidly dis-solved and readily and reproducibly synthesi~ed.
E2-CDS and several other CDS have a1so been successfully complexed with other cyclodextrin deriva-tives as defined herein. The other cyclodextrin/CDScomplexes have the improved characteristics as noted before for the HPCD complexes.
In one example of the formulation of a solid complex, an excess of a representative CDS, E2-CDS, was added to a 40~ aqueous solution of a mixture of maltosyl-~-cyclodextrin (71~) and various dimaltosyl-B-cyclodextrins (29~) obtained from Ensuiko Sugar Co., Ltd., Lot No. 853190, and mixed for several hours. The suspension was then filtered and freeze-drted, and the amount of complexed drug was determined analytically by UV spectraphotometry. The amount of incorporation was determined to be 81.88 mg/g. The comparable figure for HPCD is approximately 36.2.
In further testing, maximum concentrations of selected COS in varying concentrations of selected cyclodextrins were determined. The concentration of E2-CDS (mg/mL) was as follows:

Cyclodextrin 20~ 40 HPCD 6.73 11 . 9 HEBCD 3.09 6.07 HPGCD -- 4.0 The concentration (mg/g) of the norethindrone-CDS was 7.13 in 40~ HPCD and 15.9 in 40~ HPGCD.

As noted above, use of a representative dihy-dropyridine redox system drug, i.e. E2-COS, com-plexed with a representative cyclodextrin deriva-tive, HPCD, led to lower initial lung concentrations (and thus increased initial brain to lung concentra-tions) of the quaternary form as compared to adminis-tration of the redox system drug in DMS0. In studies of another representative redox system drug, namely a testosterone-CDS, T-CDS1, similar observations were made, as detailed below.

EXPERI~E~TAL SECTrOH

~aterials: 2-Hydroxypropyl-B-cyclodextrin (HPCD, degree of substitution 5.1) was prepared and purified according to the method of Pitha et al. The cyclodex-trin inclusion complexes were prepared hy equilibratingan excess of either testosterone propionate or T-COS
with a 50X w/v aqueous solution of 2-hydroxypropyl-B-cyclodextrin. The solution was degassed and the suspension was sonicated for 30 minutes, after which it ~as filtered and the filtrate was lyophilized. ~he dried filtrate contained 65.6 mg testosterone propionate or 29.6 mg T-CDS1 per gram of cyclodextrin complex. Compounds were analyzed for decomposition by thin-layer chromatography and ultraviolet absorption.

Antmals: Male Sprague-Dawley rats, weighing 250-275 9, were purchased from Charles River Breeding Laboratories (~ilmington, MA) and were housed in an animal room which was light (14 hours; lights on at 0500 hours) and temperature (23 ~ 1 C) controlled. To elevate serum luteinizing hormone (LH) and to reduce the source of endogenous testosterone, antmals were bilaterally orchidectomized via a mid-ventral incision under light ether anesthesia. All experiments were initiated 2 weeks after orchidectomy.

Expertment 1: On day 15 after orchidectomy, rats were ether-anesthetized and the right external jugular vein exposed. Animals were then administered one of the following: testosterone-chemical delivery system (T-CDSl or T-CDS2), testosterone (Steraloids ~nc., Wilton, NH) or the vehicle, dimethyl sulfoxide (DMSO; Fisher Scientific, Fair Lawn, HJ). The testosterone-chemical delivery systems were given at doses equimolar to testosterone (25 mg/kg) so that T-CD51 was administered at 35.5 mg/kg and rats received T-CDS2 at a dose of 45.1 mg/kg. ~SO was injected at a volume of 1 mL/kg. All compounds were administered by infusion over a 2 minute period. One milliliter of blood was withdrawn from the external jugular vein immediately before giving the drugs (1000 hours) and blood was sampled by cardiac puncture after 6, 12, ~4 hours and on days 4 and 7. The sera were separated by centrifu-gation at 500 x 9 for 20 min at 4C and stored at _20C .

Exper1~ent 2: Two weeks after orchidectomy, rats were administered either T-CDSl, testosterone propionate - loo- 1 3 3 6 4 9 8 (TP; Steraloids Inc.) or DMSO by means of intravenous infusion into the right external jugular vein in an effort to more effect~vely enhance the brain delivery of testosterone. It has been shown that slo~ infusion improves brain delivery of drugs attached to the chemical-dellvery systems. TP was selected for com-parison since it, like both of the T-COS compounds, has an ester grouping (propionate) attached at carbon-17 (C17). Gonadally-intact animals received the drug vehicle only. Two Harvard Apparatus reciprocal infusion/withdrawal pumps (model 944) were used so that 4 animals could be simultaneously infused. Rate of infusion was 15 ~L/min and animals were infused for 17 to 25 minutes. TP was given at 25 mg/kg and T-CDS was infused at a dose equimolar to TP (29.7 mg T-COS1 per kg body weight). The drug vehicle, ~MSO, was adminis-t~red at a dose of 1 mL/kg. One mL of blood was removed from the external jugular vein prior to drug infusion and from the sub-orbital sinus at 1, 3, 5, and 7 days. The sera were separated and stored as pre-viously described.

Experiment 3: Orchidectomized rats were administered either testosterone-chemical delivery system (T-CDS1) in HPCD (T-CDS1-HPCD), testosterone propionate in cyclodextrin (TP-HPCD) or the vehicle, cyclodextrin (HPCO), via a single tail vein injection. T-CDS1-HPCD
(11.9 mg/kg) was given so that animals received T-CDS
at a dose e~uimolar to TP-HPCD (10 mg TP/kg body weight). Control rats received 25X HPCD (w/v) at 3.0 mL/kg. ~lood was removed by cardiac puncture on days O, 1, 3, 5 and 7, and separated and stored as pre-viously described.

To evaluate pertpheral effects of the drugs, the right sem~nal vesicle, vas deferens and ventral pros-tate gland were removed, cleaned, expressed of fluid and we~ghed to n.l mg. Data are reported as mg per 100 9 body wetght.

Rad10~unoassay of LH: Serum LH concentrations ~ere determined in dupl~cate w~th a rad~otmmunoassay kit (reference preparation LH-RP-2~ provided through the Pituitary Hormone Distribution Program of the NIADDK.
The intra- and interassay coeff~cients of variation were 2.9 and 15.6, respectively.

R~d~o1~unoassa~ of Testosterone: Serum testosterone concentrations were determined in duplicate with a Coat-A-Count radioimmunoassay kit (Diagnostic Products;
Los ~ngeles, C~).

Stat~st~cal treat ent: The significance of difference among mean values for LH and peripheral tissues was determined by analysis of variance (ANOVA) and Student-Newman-Keuls (SNK) tests. The level of significance for both tests was O.OS.

RESULTS ~ND DlSCUSSlON
In Experiments 1 and 2, in which nMS0 served as the drug vehic~e, indications of drug insolubility upon injection were observed, i.e. respiratory distress accompanied by lesioning of the lungs, regardless of the rate of injection or infusion. In an effort to increase water solubility of the steroids, T-CnSl and TP were solubilized in a HPCn in Experiment 3. The improvement in solubllity for the T-CDS1 suggests that l 336498 a lo~er dose (10 mg/kg vs. 25 mg/kg) could be administered ~ith, presumably, a diminished risk of toxicity to the animal. A 2.5-fold decrease in T-CDS
dosage resulted in a similar suppression of serum LH
levels observed in the prevtous two experiments. An injection of T-CDSl-HPCD resulted in a snX decrease in serum LH by 24 hours and this suppresslon was observed through 3 days. Suppression of ~H occurred in animals treated with TP-HPCO at day 1 only.
Mild sti~ulation of the seminal vesicles by T-CDSl-HPCD and of the ventral prostate gland by T-CDSl-HPCD and TP-HPCD was observed at 7 days post-injection. As observed previously, the extent of stimulation by T-COSl-HPC0 or TP-HPCD was minor relative to tissue weights observed in control (gonadally-intact) rats.
A 5.5-fold increase in serum testosterone was observed 1 day after rats were administered T-CDSl-HPCD
and serum testosterone remained elevated at day 3.
~owever, testosterone levels returned to pre-injection levels 5 days after injection. At no ti~e did TP-HPCD
or HPC~ induce an increase in serum testosterone.
These experiments offer support for the improved delivery of testosterone to the brain when the repre-sentative redox carrier drug, T-CDSl, is complexed to the representative cyclodextrin, HPCD. The data show an equivalent suppression of LH by complexing T-CDS
to HPCD and lowering the effective single dose of T-COSl by 2.5-fold. This finding implies that the dihydropyridine form of T-CDSl remains in solution in an aqueous medium (e.g. blood) for a longer time, thereby permitting improved passage of the drug through the blood-brain barrier. Earlier studies revealed thatl when administered in a DMS0 vehicle, ~-CDS
probably precipitated in the blood (and lungs), causing respiratory distress and/or death in rats.
No respiratory distress or animal loss occurred when T-CD51 was complexed with HPCD.
To quantitate the improvement provided by the representative cyclodextrin, HPCD, in lowering initial lung concentrations of redox carrier compounds compared to brain concentrations, another series of experiments was undertaken investigating the HPCD
complex of E2-CDS. These studies, which are detailed below, utilize a reversed-phase-high-performance liquid chromatographic method for the analysis of E2-COS and its oxidized quaternary metabolite E2-Qu~t in biological fluids or tissues. The assay utilizes a precolumn enrichment technique and detects plasma levels down to 10 ng/mL E2-Quat and 20 ng/mL E2-COS.
Sample preparation is rapid and simple. Samples are homogenized with acetonitrile, centrifuged, and the supernatant is directly injected into the HPLC-system. A water-delivering pump injects the sample on a pre-column where the drug is concentrated.
Mobile phase backflushes the retained compound onto the analytical column. At the same time, another sample can be injected onto a second pre-column. This alternating pre-column sample enrichment technique allows the injection of large volumes up to 1800 ~L.

E~PERItiE~rAL SECrlO~I

~aterials: E2-CDS, E2-Quat and E2-CDS-HPCD were synthesized as described previously. Steroids (estradiol and ethinyl estradiol) were obtained from Stgma Chemical Co. HPLC grade acetonitrile and dis-tilled, de10nt~ed water were used for the preparation of mobile phases. All other reagents used were of analytical grade.

~nstru~entation: The HPLC system consisted of a LDCI~ilton Roy Constametric III high-pressure pump, a LDC/Milton Roy variable wavelength UV detector, a Perkin Elmer ISS-100 automatic injector equipped with a 2000 ~L loop and a DuPont Zorbax ODS column, 15 cm x 4.6 mm I.D. (6 ~m particle size). Vydac guard columns (5 cm x 3.2 mm I.D.), dry-packed with OuPont Zorbax~ODS
material, were used. Chromatograms were recorded on a Hewlett-Packard Model 3390A computing integrator at a chart speed of 0.2 cm/min. In addition, in the pre-column enrichment system, an enrichment injector (Rheodyne ~odel 7067-OOS) with two high pressure switching valves, pneumatically turned by a tandem actuator (Rheodyne ~odel 7163), was inserted between the autoinjector and the analytical column. Switching of the valves was controlled via the autoinjector.
~his system also contained a Bodine Electric Co. ~R/035 HPLC Solvent Pump for flushing the samples onto the enrichment columns.

~ethods:
Assa~ Conditions: d~rect on-l~ne HPLC
Chromatographic conditions for the analysis of E2-~a~e ~

COS, E2-~uat and estradiol were developed. The optimal wavelength for all compounds was 224 nm, but E2-CDS can also be detected at 360 nm due to the dihydropyridine structure. Although the absorptivity at thls wave-length is onl~ about half as high as it is at 224 nm,360 nm was chosen as the analytical wavelength for E2-CDS because of the increased selectivity. ~ifferentanalytical columns were tested and mobile phases for a reversed phase chromatography of all three compounds were varied widely with respect to the ratio of aqueous and organic phase as well as buffer concentration and pH. ~o isocratic system could be found that would detect all three compounds within a reasonable reten-tion time and with satisfying compactness and separa-tion of peaks. Therefore, two different systems wereused for analysis.
E2-~uat and E2: The optimal mobile phase was found to consist of acetonitrile/water 40:60 containing 0.03 M/L sodium salt of octanesulfonic acid and 0.003 ~/L tetrabutylammonium phosphate. The pH was adjusted to pH 5-5.5. The flow rate was 1.5 mL/minute and the peaks were recorded at 224 nm.
E2-CDS: The mobile phase used for E2-CnS analysis ~as acetonitrile/water 70:30 at a flow rate of l.5 mL/minute. Absorbance was monitored at 360 nm.

Analys~s of E2, E2-CDS and Ez-Quat by pre-column enrichment technique-The loss of sensitivity resulting from thedilution step in the procedure optimtl for pre-treatment of biological samples (see sample preparationwithout extraction) could he compensated for by developing an HPLC system that allows injection of large volumes. A suitable HPLC-method wh~ch has been described in the llterature [Roth et al, J. Chromatogr.
222: 13-22 (1981)] Is based on alternat~ng pre-column sample enrichment. The procedure used herein was as follows: The sample containing the drug is injected with a first pump A, deliver~ng pure water, onto one of two pre-columns, which are alternatingly connected with the injection system by two pneumatically driven valves. Provided a certain llpophilicity, the drug is retained and concentrated on the pre-co1umn, while accompanying water soluble co-products like proteins are being washed out as long as water is pumped through the pre-column. This allows the direct injection of body fluids. After a certain enrichment time (6 and 8 minutes), simultaneous rotation of the two valves is induced, causing pre-column 1, where the injected drug has been absorbed, to be switched to the solvent stream of the second pump, B. Also, at this point, the recording integrator is started. Pump B delivers the mobile phase, necessary for separation and chromatography, and backflushes the sample from pre-column 1 onto the analytical column. Parallel to this process, pre-column 2 is switched to the water stream of pump A so that a sample can be injected and enriched while the previous one is being eluted (alternating mode). Volumes up to 1800 ~L can be injected due to the concentration effect of the enrichment phase.
Chro~atographic cond~t~ons: This system was applicable to the quantification of E2, E2-CDS and E2-Quat. The mobile phase for E2-CDS was: Acetoni-trile/water 80:20 at a flow rate of 1.8 mL/minute.

-107- l 3 3 6 4 9 8 Optlmal peak shape and retention time for E2 and E2-Quat were obtained ~ith pump B delivering a mixture of acetonitrtle/water 42:58 whlch contained 0.025 ~/L
sodtum salt of 1-octanesulfonlc acid and 0.003 ~/L
tetrabutylammonium phosphate. rhe pH was adjusted to pH 5, and the flow rate was 1.5 mL/minute.

Standard solut~ons and stab~l~ty Sample stock solutions of E2-CDS, E2-Quat, E2 and ethinyl-E2 containing each 50 ~g/mL were prepared in acetonitrile. All solutions were stored at 6C. For E2-COS, the stock solution was prepared freshly every 2 weeks. All other solutions were stable over a period of at least six months. Spiked plasma samples con-taining all four compounds were frozen at -20C and analyzed repeatedly at different time intervals. No loss of drug was found under these storage conditions during two months.
ni hydropyridine derivatives like E2-CDS are known to be easily oxidized and very labile in acidic solu-tions. The stability of E2-CDS was investigated under different conditions at room temperature. These studies were performed by dilut1ng the E2-CDS stock solution 1:2 with d1fferent solvents or solutions at different pH values and monitoring eventual peak height loss for 24 hours by use of a modification of the direct on-line HPLC method described above: If water in the E2-COS mobile phase is replaced by 0.05 ~
phosphate buffer at pH 7 and if the detection wave-length is set to 224 nm, E2-Quat can be detected simul-taneously at 6.33 min. However, the peak is relativelybroad. These conditions were used to determine the degree of E2-COS ox~dation under the tested conditions.

Sa~ple preparation Extract~on of E2-Quat and E2: Various extraction procedures from plasma were investigated under dif-ferent conditions and with several solvents and solvent mixtures. Estrone could be used as an internal standard, but is known to be a potential metabolite of estradiol. Therefore, 17-B-ethinyl estradiol was chosen as internal standard. Its peak did not inter-fere wtth E2, E2-Quat or estrone. Without addition of an anion reagent~ E2-Quat could not be extracted from aqueous solutions. Optimal results were obtained after a single-step extraction of the drugs with potassium iodide as an ion-pairing reagent to facilitate quaternary salt extractton. The method applied was as follows: 200 ~L of a saturated potassium iodide solution were added to 1 mL of spiked plasma. After vortexing for a few seconds, 1n mL of a mixture of chloroform/ethyl acetate 9:1 was added. The tubes were shaken for 10 minutes and then centrifuged for 10 minutes at 2000 rpm. The upper aqueous phase was discarded and the organic layer transferred to a clean tube to achieve complete separation from proteins and traces of aqueous phase. The organic layer was eva-porated to dryness under n~trogen at 40C and recon-st~tuted in 15n ~L of mobile phase. 4n ~L wereinjected into the ~PLC system. Appropriate blanks were prepared accordingly.
Extract~on of E2-CDS: Plasma and water containing E2-CDS were repeatedly extracted with different organic solvents like chloroform, hexane, toluene, benzene and ethyl acetate. It was impossible to extract E2-CDS

reproducibly from aqueous phases, since the compound was shown to deteriorate unreproducibly during evapora-tion, even at room temperature and in the presence of oxygen-free nitrogen. Therefore, the compound had to he analyzed from biological fluids without an extrac-tion procedure.
Preparation of plas~a and tissues for anal~sis of E2-COS and Ez-Quat ~ithout extract~on: Using the HPLC
technique with pre-column enrichment described above, ~rugs can he detected from directly injected plasma without sample preparation. However, when large volumes are injected, in order to obtain maximum sensi-tivity, it is desirable to remove proteins to a large extent prior to injection in order to prevent frequent pre-column packing. The procedure of deproteinization was chosen to be applicable for subsequent analysis of both E2-CDS and E2-Quat so that only one preparation step had to be performed.
~cidic precipitating agents, which remove proteins when only small volumes are added to biological fluids, could not be used because they induce degradative loss of E2-C~S. Neutral or slightly basic aqueous reagents used efficiently for deproteinization like ZnS04/NaOH, CuS04/Na2S04 or saturated (~H4)2S04 would be more ideal to be injected onto the enrichment columns than organic solvents. ~ut all of these reagents were shown to absorb the water-insoluble E2-CDS on the precipitate.
Thus, the method of choice to avoid instability prob-lems and at the same ttme keep all compounds in solu-tion was deproteinizatton w1th acetonitrile.

- 1 1 o -To obtain these results, the following sample preparation procedures were used for plasma and tissues: Plasma: 0.6 mL plasma was added to 1.2 mL
acetonitrile. The mixture was vortexed for 5 seconds and allowed to stand for 10 minutes at room tempera-ture, vortexed again and centr~fuged for 10 minutes at 2noo rpm. 1000-15'00 ~L of the supernatant was injected into the pre-column enrichment system. Tissue (e.g.
brain): 1 mL of water was added to one rat brain and the organ was thoroughly meshed. ~fter sonication for 2 minutes and centrifugation at 2000 rpm for 10 minutes, the supernatant (1000-1500 ~L) was injecte~
into the enrichment system.

Animal Studies:
In a first experiment, 15 mg/kg E2-CDS dissolved in dimethylsulfoxide (OMSO) were administered intra-venously to conscious, restrained male Sprague-Dawley rats weighing 190-300 9 each. ~nimals were sacrificed in groups of 4 at 5, 15 and 3n minutes and at 1, 2, 4, 8, 24 and 48 hours after drug injection. Trunk blood was collected into heparinized tubes and plasma obtained and immediately frozen at -20C until analy-sis. Organs were dissected and placed on dry ice within 2 minutes of death and stored at -20C for later analysis by the ~PLC method described above.
rn a second experiment, the same procedure as above was followed, except that 5 mg/kg of E2-COS were administered as a complex wlth hydroxypropyl-~-cyclo-dextrin (HPCD) in water. The 5 mg/kg dose of E2-COS
was delivered in 1 mL of aqueous solution containing approximately 20~ w/v HPCD (prepared by dissolving a freeze-dried complex containing 3.5 mg E2-CDS per gram in aqueous ~OX HPC~, the freeze-dried complex having been prepared from a 50% solution of E2-CDS in HPCD
having 5.1 degrees of substitution).

Results and niscussion The results are depicted in FI6. 1 and F~6. 2.
FI6. 1 consists of a pair of semi-logarithmic plots comparing the concentrations in lung tissue in ~9 per 9 dose (CB/D) of E2-CDS in the first graph and of E2-Quat in the second, corrected for dose. It can be seen from FI6. 1 that when E2-CDS was administered in DMS0, initial lung concentrations (i.e. concentrations within the first hour after drug injection) of both E2-COS and Ez-Quat were significantly (more than ten-fold) higher than the initial lung concentrations observed when E2-CDS was administered as a complex with HPCD in water.
~he corresponding levels of E2-Quat in brain tissue, also corrected for dose, are given in FIG. 2 in the 2~ form of a bar graph depicting the brain levels in ng per g dose (CB/D) at selected time points. ~t can be seen that the brain levels after 1 hour are not significantly different for administration as HPCD
complex in water as compared to administration in D~S0. Clearly, then, the carrier-drug can be administered as a complex with a selected cyclodex-trin as defined herein, such as HPCD, in water and still achieve the brain levels needed to produce the desired biological effect, while avoiding the hig~
initial lung concentrations responsible ~or respira-tory distress and dysnia.

-112- l 3 3 6 4 9 8 Complexation with 2-hydroxypropyl-B-cyclodextrin (HPCD~ or other selected cyclodextrin derivative as defined herein has been found to be particularly advan-tageous in that it stabilizes the dihydropyridine redox systems. A direct comparison of stabilities in aqueous solution is, of course, not possible because of the low solubility of the dihydropyridine redox system drugs in water; for example, the solubility of E2-CDS in water is only 0.0002 mg/mL. The E2-CDS-HPCD complex contains about 40 mg of E2-CDS/g and easily gives aqueous solu-tions containing 5 mg E2-CDS/mL at 20X w/v cyclodex-trin. Thus, complexation affords a 25,000-fold in-crease in aqueous solubility of E2-CDS. The halflife of E2-CDS in such a solution at room temperature in the dark is about 12.5 days (rate: 0.0554 + 0.0047d-1).
Since the dihydropyridine redox system drugs are especially prone to oxidative degradation, a study was undertaken to quantitate the effect of a cyclodextrin derivative intended for use herein, e.g. HPCD, on the rate of oxidation of these ~rugs. A representative carrier-drug, E2-CDS, was selected for this study.
The rate of ferricyanide-mediated oxidation of E2-CDS was determined using a previously published method (Okamoto et al, J. Chem. Soc. Chem. Comm., 1977, 181). In this procedure, 27.5 ~L of a 5 x 10-3 M
solution of E2-CDS in acetonitrile was added to 2.75 mL
of a solution containing 1 x 10-4 M Fe(CN)6~4, 0.06 M
K+, O.O01 M Fe(CN)6~3. All solutions were made using water which had been boiled for 30 minutes and cooled while a stream of pyrogallol-scrubbed nitrogen passed -113- l 3 3 6 4 9 8 through it. The E2-CDS was introduced via a syringe to the solution which was maintained at 37C in a thermo-stated cell holder and contained in an anaerobic screw-top cuvette. The cuvette had a Teflon-lined septum through which the compound was injected. For a given concentration of ferricyanide ions (6 x 10-4 to 8 x 10-3 M), the rate of disappearance of the E2-CDS
was determined. This was done by calculating the decrease in the absorbance band at 360 nm (i 10 nm~
subtracted from base line absorbance (500 i 10 nm~. A
plot of the ln [Abs] versus time gave a slope for the pseudo-first-order rate constant. This was done at several different ferricyanide ion concentrations. The obtained first-order rate constants were then plotted as a function of ferricyanide ion concentration generating a slope from which the second order rate constant (ko s-1 M-1) was obtained. In examining the effect of 2-hydroxypropyl-B-cyclodextrin on the rate of E2-CDS oxidation, solutions containing the HPCD as well as those ions present in the first phase of the experi-ment were prepared. The second order constant was derived for each cyclodextrin concentration and a plot developed. The results show that the cyclodextrin dramatically slowed the rate of oxidation. There appears to be a saturation effect in that after 2% w/v, not much change in rate is evident. The second order rate of oxidation is inhibited by 42~ at 0.5% w/v cyclodextrin, 60% at 1.0% w/v, 81% at 2% cyclodextrin and at 5-20% a value of approximately 90% reduction in the rate was obtained.
From the foregoing, it is apparent that formula-tion with a representative cyclodextrin derivative as defined herein has overcome problems associated with administration of the reduced lipoidal form of dihydro-pyridine ~ pyridinium salt redox carrier systems for brain-targeted drug delivery. In particular, it has been found that administration of aqueous parenteral carrier-drug formulations comprising from about 20 to about 50~ w/w or w/v of the selected cyclodextrin, preferably hydroxypropyl-B-cyclodextrin, surprisingly changes the distribution of the drug and avoids the lung precipitation problems associated with organic solvents, leading to decreased toxicity. The advan-tageous time element, which could not have been predicted, is such that there is sufficient time after injection but before separation of the drug from the lS cyclodextrin to prevent aggregation of the drug molecules (i.e. precipitation of drug aggregates) in the lungs and other organs such as the liver, and yet the time is short enough to allow timely break-up of the drug/cyclodextrin, affording facile distribution of the drug molecules so as to achieve the desired pharma-cological effect. Other lipophilic/hydrophic and/or water-labile drugs which have heretofor been formulated for parenteral administration only in organic solvents, and/or which have simply been unavailable in parenteral form, share to various extents the same sort of prob-lems encountered with the redox carrier system and benefit from the same improved distribution and advan-tageous time element discussed above. Drugs which are particularly useful in the parenteral compositions and methods of the present invention are those which are relatively insoluble in water but whose water solubi-lity can be substantially improved by formulation with -20 to 50% of the selected cyclodextrin, e.g. HPCD, in water. These characteristics can be determined by simple experiments of the type described below for representative drugs.

Apparatus UV spectra were recorded on a Cary 210 double-beam spectrophotometer (Yarian, Palo ~lto, C~). High pressure liquid chromatography was performed on a com-ponent system consisting of Micromeritics 728 auto-sampler, Beckman 112 solvent delivery module, WatersLambda-~ax Model 481 LC spectrophotometer, and Fisher Recordall series 5000 recorder. The samples were sonicated in a Fisher Bransonic ultrasonic cleaner and equilibrated in a ~GW Lauda constant temperature water bath.

Solubility Studies Phase-solubility experiments were conducted by adding excess amounts of the drug to be tested to aqueous solutions containing various amounts of 2-hydroxypropyl-~-cyclodextrin and sonicating the mixture for one hour. After equilibration in a 25+1C water bath in the dark for at least 48 hours, aliquots of the mixtures were filtered through 0.45 ~m membrane filters, diluted and the drug concentrations measured by reversed-phase HPLC methods.
For comparison, the solubilities of the drugs in water were also determined.

-116- l 3 3 6 4 9 8 HPLC ~ethods Chlordiazepoxide Wavelength: 245 nm Column: Waters ~Bondapak CN, 3.9 mm (i.d.) x 30 cm ~obile phase: acetonitrile, acetic acid, water (60:1:39) containing 0.1X 1-hexasulfonic acid, sodium salt Flow rate: 2.00 mL/min. Retention time: 4.0 min.

Oexamethasone Wavelength: 263 nm Column: ASI C18, 10 ym, 3.9 mm (i.d.) x 30 cm Mobile phase: acetonitrile, water (55:45) Flow rate: 1.00 mL/min. Retention time: 3.6 min.

Diazepam Wavelength: 241 nm Column: Waters ~Bondapak CN, 3.9 mm (i.d.) x 30 cm Mobile phase: acetonitrile, water (6:4) Flow rate: 2.00 mLtmin. Retention time: 3.2 min.

17B-Estradiol Wavelength: 280 nm Column: AS~ C18, 10 ~m, 3.9 mm (i.d.) x 30 cm Mobile phase: acetonitrile, water (55:45) Flow rate: 2.00 mL/min. Retention time: 4.4 min.

17~-Ethynylestradiol Wavelength: 248 nm Column: Fisher Resolvex C18, 4.6 mm (i.d.) x 25 cm ~obile phase: acetonitrile, water (6:4) Flow rate: 1.50 mL/min. Retention time: 4.4 min.

Ethynylestradiol 3-methyl ether Wavelength: 248 nm Column: Fisher Resolvex C18, 4.6 mm (i.d.) x 25 cm Mobile phase: acetonitrile, water (7:3) Flow rate: 2.00 mL/min. Retention time: fi.0 min.

Medazepam Wavelength: 253 nm Column: Waters ~Bondapak CN, 3.9 mm (i.d.) x 30 cm Mobile phase: acetonitrile, acetic acid, water (60:1:39) containing O.lX 1-hexanesulfonic acid, sodium salt Flow rate: 2.00 mL/min. Retention time: 2.8 min.

~ethotrexate Wavelength: 308 nm Column: Fisher Resolvex C18, 4.6 mm (i.d.) x 25 cm ~obile phase: methanol, acetic acid, water (50:1:49~
containing 0.1X~ 1-octanesulfonic acid, sodium salt Flow rate: 2.00 mL/min. Retention time: 3.5 min.

Horethindrone Wavelength: 240 nm Column: Fisher Resolvex C18, 4.6 m~ (i.d.) x 25 cm ~obile phase: acetonitrile, water (6:4) Flow rate: 1.50 mL/min. Retention time: 3.6 min.

~orethindrone acetate Wavelength: 240 nm Column: Fisher Resolvex C18, 4.6 mm (i.d.) x 25 cm Mobile phase: acetonitrile, water (7:3) Flow rate: 2.00 mL/min. Retention time: 5.0 min.

D(-~-Norgestrel Wavelength: 241 nm Column: Fisher Resolvex C18, 4.6 mm (i.d.) x 25 cm Mobile phase: acetonitrile, water (7:3) Flow rate: 2.00 mL/min. Retention time: 3.4 min.

Oxazepam Wavelength: 230 nm Column: Waters ~Bondapak CN, 3.9 mm (i.d.) x 30 cm Mobile phase: acetonitrile, water (35:65) Flow rate: 2.00 mL/min. Retention time: 2.6 min.

Phenytoin Wavelength: 258 nm Column: Fisher Resolvex C18, 4.6 mm (i.d.) x 25 cm Mobile phase: acetonitrile, water (55:45) Flow rate: 2.00 mL/min. Retention time: 1.6 min.

all-trans-Retinol Wavelength: 325 nm Column: Waters ~Bondapak C18, 10 ~m, 3.9 mm (i.d.) x 30 cm Mobile phase: acetonitrile, water (55:45) Flow rate: 1.00 mL/min. Retention time: 5.8 min.

Results Solubilization of Drugs by 2-Hydroxypropyl-B-Cyclodextrin in Aqueous Solution at 25~1C.
5Solubility in HPCD
Solubility - Water Solution - Increase in in water Conc. of Solubility Solubility Dru9a (mg/mL) HPCD (~g/mL)(HPCD/water) Chlordiazepoxide o~olb 50X w/w 147.8 ~15,000 Dexamethasone 0.008 50X w/w 44.3 -5,500 Diazepam n.o5b 50X w/w 7.4 ~150 17B-Estradiol 0.004b 50X w/w 40.5 ~10,000 17o-Ethynyl-estradiol 0.008 50X w/w 68.2 ~8,500 15 Ethynylestradiol 3-~ethyl ether 0.001 50X w/w 13.3 ~13,000 Medazepam (pH 7.5) 0.01 50X w/w 8.3 ~850 ~ethotrexate (p~ 7.6) n.o45 50X w/w 1n.0 ~200 Norethindrone n.on5 50X w/w 19.0 ~4,000 Norethindrone acetate 0.0002 50X w/w 19.5 ~97,500 D(-)-Norgestrel 0.002 50X w/w 4.9 ~2,500 Oxazepam 0.03 50X w/w 4.2 ~150 Phenytoin n.o2 50X w/w 9.3 ~450 All-trans-Retinol 0.001 50X w/w 4.6 ~4,600 a) pH of the 2HPCD solution given when monitored.
b) Literature values TABLE IV
Solubilizatton of Drugs by 25X w/v Aqueous Hydroxy-propyl-~-Cyclodextrin at 25+1C.

~rug Solubility (mg/mL) ~examethasone 24.18 17B-Estradiol 19.13 17a-Ethynylestradiol 34.47 17a-Ethynylestradiol 3-methyl ether 7.13 Norethindrone 9.13 Norethindrone acetate 9.41 D(-)-~orgestrel 2.19 ~pparatus UV spectra were taken on a Perkin-Elmer 550 SE
double-beam spectrophotometer. rhe high pressure liquid chromatography was performed on a component system consisting of ~heodyne 7125 injector, LKB 2150 ~PLC pump, LKB 2138 Lichrosorb ~P18 10 mm column (4x250 mm), LKB 21~8 uvicord 5 detector and Omniscribe ZO recorder. The samples were sonicated in a Kerry Ultrasonic bath and equilibrated in Tecam TE-7 Tempette constant temperature water bath.

Solub~l~t~ Studies Phase-solubility experiments were conducted by adding excess amounts of the drug to be tested to aqueous solutions containing various amounts of 2-hydroxypropyl-B-cyclodextrin (~PCD) and sonicating the m~xtures for up to four hours. After equilibration in a 30.0~0.2C water bath in the dark for up to 72 hours, aliquots of the mixtures were filtered through 0.45 Mm membrane filters, diluted and the drug concentration determined by HPLC or UV methods. The sonication and equilibration time was kept at a minimum because of the instability of the drugs.

HPLC ~ethods Chlorambucil Wavelength: 245 nm Mobile phase: acetonitrile, acetic acid, water (45:1:54) Flow rate: 2.00 mL/min.
Retention time: 4.4 min.

Lomustine Wavelength: 254 nm Mobile phase: methanol, water (7:3) Flow rate: 2.00 mL/min.
Retention time: 3.6 min.

Melphalan Wavelength: 254 nm Mobile phase: Methanol, acetic acid, water (60:1:39) ~ n.19X l-pentanesulfonic acid, sodium salt.
Flow rate: 2.00 mL/min.
Retention time: 3.6 min.

Results Chlorambucil The preliminary experiment indicated that the solubility was about 30 mg/g in 50X w/w HPCD/H20 solution (sonication for 30 min. followed by equilibration at 30 for 4 hours). The drug is almost insoluble in water and the p.o. dose is about 100 mg/kg/day. Further experiments were done and the results are shown in TABLE V. Significant degradation occurred during the experiments (3.5 days).

Lomustine The initial experiment indicated that the solubility was about 12 mg/g in 50~ w/w HPCD/H20 solution. The results of the follow-up experiments are shown in TABLE VI. Some degradation occurred.

~elphalan The initial experiment indicated that the solubility was about 21.9 mg/g in 50X w/w HPCD/H20 solution (sonication for one hour followed by equilibration at 30 for 4 hours). The results of the follow-up experiments are shown in TA~LE V~. Some degradation occurred.

TABLE V

Solubility of chlorambucil in aqueous solutions of 2-hydroxypropyl-B-cyclodextrin (HPCD) at 30.0+0.2C.

Solubility (mg/mL) X w/v HPCD (1) (2) o o.nl n.4l 1 n.74 0.55 2 1.48 n.84 3 2.37 0.68 4 3.22 1.50 1.46 1.80 7 2.71 3.76 4.96 5.20 6.36 7.60 ~.49 13.09 8.85 18.40 (1) Sonication for 45 min. followed by equilibration at 30 for 3 hours.
(2) Sonication for 4 hours followed by equilibration at 30 for 3.5 days.

TABLE VI
Solubility of 10mustine in aqueous HPCD solutions at 30+0.2C.

X w/w HPCn Solubility (mg/mL)*
0 0.18 1 n.38 S 1.68 3.33 6.26 8.44 ~.9 *) The figures shown are average numbers from up to four experiments.
TABLE VI r Solubility of melphalan in aqueous HPCn solutions at 30.0~0.2C.

X w/v HPC0 Solubility (mg/mL)*
n 1.26 1 4.16 2 4.3 3 6.24 4 7.14 7.2 7 10.5 13.37 17.64 2n 24.75 31.36 *) The figures shown are average values of several 30experiments.

TABLE VI I ~

Chlorambucil Lomustine ~elphalan p.o. dose, *)0.1-0.2 mg/kg**130 mg/m2*** 2-35 mg**
i.v. dose, *) - - -solubility in water (mg/g) 0.41 0.18 1.26 solubility in 25~
w/v HPCn (mg/g)18.4n 8.9 31.36 solubility in 2~
~/v HPCD (mg/g)13.n9 8.44 24.75 increase:
water/25~ HPCn44.88 49.44 24.89 *) From the Icelandic drug manual.
**~ Daily dose.
15 ***) Every 6 weeks.

Solubility Studies Phase-solubility experiments were conducted by adding excess amounts of alfaxalone to phosphate buffer solutions containing 20~ w/v of selected cyclodextrins 20 and sonicating the mixtures for at least one hour.
(The phosphate buffer solution was prepared by dis-solving 1.183 g KH2P04 and 4.320 g Na2HP04 in water and diluting to 1 liter.) The mixtures were filtered through .45 ~m Millipore syringe filters and diluted 25 and the drug concentrations were measured by reversed ~hase HPLC methods. Alfaxalone itself is virtually insoluble in water.

~PLC Methods for Alfaxalone Wavelength: 294 nm Mobile phase: methanol:water (65:35) Flow rate: 1.5 mL/min.
Retention tiem: ~ 14 min.

The results of these studies are summarized in TABLE IX below.

TABLE IX

Solubilization of Alfaxalone by 20~ w/v Solutions of Selected Cyclodextrins at Room Temperature Cyclodextrin Solubility (mg/mL) maltosyl-~-cyclodextrin mixture 20.02 hydroxypropyl-~-cyclodextrin 18.41 hydroxypropyl -Y-CyCl odextrin 15 .11 hydroxypropyl-B-cyclodextrin 22.83 hydroxypropyl-B-cyclodextrin 24.42 The followi ng Exampl es illustrate the preparation of preferred reduced, dihydropyridine + pyridinium salt redox carrier systems for brain-targeted drug delivery which are contemplated for use in accord with the present invention and which have not been specifically described in publications to date.

EXA~PLE 1 Preparation of N-Nicotinoyldopamine:
To a pyridine solution containing 11.7 9 (O .S
molJ dopamine hydrobromide and 6.15 9 (0.05 mol) nicotinic acid at 0C were added 10.3 9 (0.05 mol) dicyclohexylcarbodiimide (DCC). The reaction mixture was stirred at room temperature for 24 hours and the formed dicyclohexylurea was removed by filtration. The pyridine was removed ~n vacuo and the residue was crystallized from water at 0C. rhe product was isolated by filtration and dried over phosphorous pentoxide. Recrystallization from isopropanol gave 9.0 9 (0.035 mol), 70X N-nicotinoyldopamine, m.p. 159-162C; aqueous solution of the compound gave a green color with Fe+3 and reduced AgN03; rR (KBr) 3300, 2960, 1725, 1630, 1590, 1520, 1430, 1290, 1190, 1115, 720 and 710 cm~l; NMR (d6-DMS0) ~ 9.25-6.25 (m, 7H), 3.3 (m, 2H) and 2.65 (m, 2H) ppm. Anal. (C14H14N203) C, H, N.

EXA~PLE 2 Preparation of l-Methyl-3-f~-[g-(3,4-dihydroxyphenyl)-ethyl]}carbamoylpyridinium iodide:
To a solution of 2 9 (7.7 mmol) of N-nicotinoyl-dopamine in 40 mL of dry methanol were added 2.5 9 (17.6 mmol) of methyl iodide. The reaction mixture was refluxed with stirring for 6 hours. Methyl iodide (1.5 9, l.OS mmol) was added and refluxing was continued overnight. Methanol was removed and ethyl acetate was added, affording yellow~sh crystals of the desired product. Yield 2.4 9 (77S), m.p. 173-174C.

EXA~PLE 3 Preparation of l-Methyl-3-~N-t[B-[3,4-bis(isobutyryl-oxy)phenyl~ethyl~carbamoylpyridtnium trifluoroace-tate:
To an ice-cold solution of the product of Example 2 (3 9. 7.5 mmol) in 30 mL of trifluoroacetic acid, isobutyryl chloride (2.4 9, 22.5 mmol) was added slowly, with stirring. Stirring was continued over-night at room temperature. Trifluoroacetic acid was evaporated under vacuum and the residue was crystal-lized from ethyl ether:hexane (3:1). Yield 1.2 9 (30.4~), m.p. 87-91C.

EXA~PLE 4 Preparation of l-Methyl-3-~N-[CB-[3,4-bis(isobutyryl-oxy)phenyl~ethyl~carbamoyl-1,4-dihydropyridine:
A solution of 0.55 9 (1 mmol) of 1-methyl-3-{N-[[~-[3,4-bis(isobutyryloxy)phenyl~ethyl]]}carbamoyl-pyridinium trifluoroacetate in 50 mL of deaerated water containing 10 mL of methanol was extracted three times wtth 3n mL portions of ether. To the resultant aqueous solution were added NaHC03 (0.25 9, 3 mmol) and 50 mL
of ethyl ether and the mixture was kept under nitrogen. To this ice-cold mixture was added sodium dithionite (0.52 9, 3 mmol) and the mixture was stirred vigorously for 30 minutes. The ether layer was sepa-rated and the aqueous layer was extracted twice with ether. The combined ether extracts were washed with water and drted over sodium sulfate. Ether was removed under vacuum, leav1ng an otly product. N~R analysts confirmed that the product had the structural formula:

~ ~ OCCH(CH~)2 1~ ~2~ 0CCH(CH~)2 EXA~PLE S
Preparation of 5,5-Diphenyl-3-hydroxymethyl-2,4-imidazolidinedione:
Phenytoin (5 9, 0.02 mol) was suspended in 180 mL
of water; 20 mL of formaldehyde (37X solution) and 0.25 g K2C03 were added and the mixture was stirred at 25-30C for 24 hours. The white solid which formed was removed by filtration and washed repeatedly with a 3X
solution of formaldehyde, then air-dried for 3 to 4 hours and over P205 in a vacuum dessicator. Yield 91-93X, m.p. 185-189C. Anal. calc. for C16H14N203: C, 68.07; H, 5.00; N, 9.93. found: C, 67.97; H, 5.05; H, 9.93. rhe product had the formula:

~ ~
~20H

EXA~PLE 6 Preparation of S,5-Diphenyl-3-t(3'-pyridyl)carbonyloxy-methyl]-2,4-imidazol1dinedione:
rhe product of Example S (3.00 g, 0.011 mol) was dissolved in 150 mL of dry pyridine. then nicotinic anhydride (4.25 9, 0.019 mol) was added. The resultant solution was stirred at room temperature (25-30C), under dry conditions, for 40 hours. The solution was poured into 2.5 L of water and the resultant white solid was removed by filtration, washed well with water and dried over P205 in a vacuum dessicator. 95X yield, m p 178-182C. Anal calc. for C22Hl7~304: C, ~, 4.42; N, 10.85. Found: C, 68.12; H, 4.43; N, 10.83. The product had the formula:

~ N

EX~PLE 7 Preparation of 5,5-Diphenyl-3-~(1'-methyl-3'-pyri-d1nium)carbonyloxymethyl]-2,4-imidazolidinedione 1Od1de:
The product of Example 6 (0.5 9, 0.0013 mol) was d1ssol~ed 1n 50 mL of aceton1tr11e, then 0.3 mL of methyl 1Od1de was added and the react1On m1xture was mainta1ned at room temperature for 6 days. The solvent was removed by vacuum distillation and ethyl ether was added to the residue. The ether solution was refrig-erated for 2 hours, then the yellow, hygroscopic crys-tals which formed were dried over P205 in a vacuum dessicator, giving the desired product in 85S yield.
UV and ~lHMR spectra confirmed that the product had the structure:

~N~
~ ~ ~ CH3 Repeating the above procedure in nitromethane at a 50-70C bath temperature using excess methyl iodide, added gradually, for 5 to 6 hours, afforded the same product in nearly quantitative yield.

EXA~PLE 8 Preparat1On of 5,5-Diphenyl-3-[(l'-methyl-1',4'-lS dihydropyridin-3'-yl)carbonyloxymethyl]-2,4-imidazolidinedione:
The quaternary salt obtained in Example 7 (0.4 g, 0.0008 ~ol) was dissolved in 40 mL of water, 3 mL of methanol and 15 mL of ethyl acetate. The reaction mixture was cooled to 0 to 5C and deaerated, then sod1um b1carbonate (0.39 9, 0.0046 mol) and sodium d1thton1te (0.54 9, 0.0032 mol) ~ere added. The m1xture ~as stirred under n1trogen at 0-5C for 35 mtnutes. The organtc layer was removed and the aqueous layer ~as extracted twice with 15 mL portions of ethyl acetate and the organic solutions were extracted with 10 mL of cold deaerated water. ~fter drying over Na2S04. the solvent was removed by vacuum distillation 5 and the oily yellow solid was crystallized by addition of ether. Yield 70X. UV and ~lNMR analyses confirmed that the product had the formul a:

~2~

EXA~PLE 9 Preparation of 3-8romoacetyloxymethyl-5,5-diphenyl-2,4-imidazolidinedione:
5,5-Diphenyl-3-hydroxymethyl-2,4-imidazolidine-dione (2 9, 0.0071 mol) was dissolved in bromoacetyl-chloride (15 9, 8 mL, 0.096 mol) by heating in an oil bath (70-80C bath temperature) for about lS minutes, until the formation of HCl ceased. The mixture was cooled and 30 mL of ethyl ether were added. White crystals formed. rhe mixture was cooled to 0C, then the crystals were removed by filtration and dried over P205. rield: 2.15 9 (75X), m.p. 179-183C. Anal.
calc- for C18H15N24Br: C, 53.61, H, 3.75; N, 6.95;
Br, 19.82. Found: C, 53.60; H, 3.79; N, 6.92; Br, 19.90. rhe product had the formula:

;~120~C~12Br EXA~PLE 10 Preparation of 3-(3'-Bromopropionyl)oxymethyl-5,5-diphenyl-2,4-imidazolidinedione:
S,S-Diphenyl-3-hydroxymethyl-2,4-imidazolidine-dione (S 9, 0.018 mol) was reacted according to the procedure of Example 9 with 3-bromopropionyl chloride (6.~ 9, 0.04 mol, 4 mL) using a bath temperature of 100C. A white crystalline product was obtained in 65S
yield (4.9 9), m.p. 133-134C. Anal. calc. for C1gH17N204Br: C, 54.69; H, 4.11; N, 6.72; Br, 19.15.
Found: C, 54.79; H, 4.12; N, 6.69; Br, 19.25. The product had the formula:

~ `CR20~jCH2C~2Br EXA~PLE 11 Preparation of 3-(2'-Bromopropionyl)oxymethyl-5,5-diphenyl-2,4-imidazolldinedione:
5,5-Dtphenyl-3-hydroxymethyl-2,4-imidazolidine-dtone (2 9, 0.0071 mol) was dlssolved in 2-bromopro-pionyl chloride (8.5 9, 5 mL, 0.05 mol) by heating for 30 minutes on a 100-110C oil bath. The reaction mixture was cooled. 20 mL of ethyl ether were added, and the resultant solution was extracted with aqueous potassium carbonate. dried and then crystallized. The product was obtained as a sol~d wh~te substance (1 9, 34X), m.p. 112-115C. Anal. calc. for ClgH17N204Br:
C, 54.69; H, 4.11; N, 6.72; Br, 19.15. Found: C, 54.77; H, 4.15; N, 6.69; Br, 19.25. The product had the formula:

N ~

H2 ~ ~ 3 EXA~PLE 12 Preparation of 3-(3'-Carbamoyl-l'-pyridinium)acetyl-oxymethyl-5,5-diphenyl-2,4-imidazolidinedione bromide:
The product of Example 9 (2.02 9, 0.005 mol) dissolved in 15 mL of nitromethane was mixed with nicotinamide (0.61 9, 0.005 mol). The solution was stirred on a 90-100C temperature oil bath for 2 hours. The mixture was cooled to 60-70C and the white cr~stals which had formed were removed by filtration and washed with nitromethane. Yield 61X (1.65 9), m.p.
193-197C (dec). Anal. calc. for C24H21N405Br: C~
54.87; H, 4.03; N, 10.67; Br, 15.21. Found: C, 54.70;
H, 4.05; N, 10.64; Br, 15.25. The product had the Z5 formula:

OfiC~2-N ~ Br~

EXA~PLE 13 Preparation of 3-~3'-(3''-Carbamoyl-1''-pyridinium)-propionyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione bromide:
The prod~ct of Example 10 (2.09 g, 0.005 mol) was dissolved in 15 mL acetonitrile, then nicotinamide (0.61 9, 0.005 mol) was added. The solution was refluxed for 6 days, then the solvent was removed. To the gum-like residue, 30 mL of ethyl ether was added and the mixture was stirred for 2 hours. The white substance which formed was removed by filtration and washed with ether. Yield 78X (2.1 9); m.p. 98-100C
(dec.); UV and H1NMR as expected. The product had the formula:

8~ ~D~2~ CU2~N~S~r~

EXA~PLE 14 Preparation of 3-[2~-(3~-Carbamoyl_l~'_pyridinium)pro-pionyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione bromide:
S The product of Example 11 (0.69 9, 0.00165 mol) was dissolved in 8 mL of acetonitrile, then nicotin-amide (0.2 9, 0.00165 mol) was added and the solution was refluxed for 22 hours. The solvent was removed from the resultant brown noncrystalline substance at 50C, then ethyl ether (15 mL) was added and the mix-ture was stirred for 2 hours. The light brown sub-stance was removed by filtration and washed with ether. Yield 56~ (0.5 g), m.p. 158C (dec.). The product had the formula:

~ ~2 ~ ~HCH3 Br EXA~PLE 15 Preparation of 3-r(3~-Carbamoyl-l~q~-dthydropyridin-l'-yl)acetyloxymethyl]-5,5-diphenyl-2,4-imidazolidine-dione:
The product of Example 12 (0.52 9, 0.001 mol) was dissolved in a mixture of 60 mL of water and 30 mL of ethyl acetate. ~he mixture was cooled at 5C and deaerated, then sod~um bicarbonate (0.5 g, 0.006 mol) and sodium dithionite (0.7 9, 0.004 mol) were added and the resultant mixture was stirred, with deaeration and cooling, for 30 minutes. The layers were separated and the aqueous layer was extracted with 30 mL of ethyl acetate. The organic solution was extracted with 20 mL
of cooled, deaerated water. After drying over sodium sulfate, the solvent was removed. rield 55X (0.25 g) of yellow crystals, melting at 155-160C (dec.). The product reduced alcoholic silver nitrate solution and had the formula:

~ N ~ CONH2 EX~PLE 16 Preparation of 3-t3'-(3''-Carbamoyl-1'',4''-dihydro-pyridin-l''-yl)propionyloxymethyl~-5,5-diphenyl-2,4-imidazolidinedione:
Substitution of the product of Example 13 in the general procedure of Example 15 and substantial repeti-tion of the sodium dithionite reduction there detailed afforded the desired product in 85~ yield. The product melted at 100C (dec.) and had the formula:

~ 2o~r~ ,rP 2 - N~

The product of Example 14 can be similarly reduced~
to the corresponding dihydro derivative, melting at 105C (dec.~.

Preparation of 4-Aminobutanoic acid cyclohexyl ester hydrochloride:
GABA (8 9, 77.6 mmol) was suspended in 100 mL
(0.96 mol) of cyclohexanol. Thionyl chloride (40 mL) was added dropwise to the mixture at 0C. The mixture was then refluxed for 4 hours, cooled and crystallized from ethyl ether. The white crystals obtained in this manner were filtered and dried. NMR analysis confirmed the identity of the product.

Preparation of 3-{~-~(3'-Cyclohexyloxycarbonyl)-propyl~}carbamoylpyridine:
~ icotinic acid (2.2 9, 18 mmol) was suspended in 50 mL of dry pyridine. Dicyclohexylcarbodiimide (3.68 9, 17.9 mmol) was dissolved in the solution, with stir-ring. 4-Aminobutanoic acid cyclohexyl ester hydro-chloride (4 9, 18 mmol) was added and the mixture was stirred for 48 hours. Precipitated dicyclohexylurea was removed by filtration and the filtrate was evapo-rated to dryness. The residue was washed with 25 mL of ice cold water and extracted into ethyl acetate. The layers were separated and the organic layer was evapo-rated to dryness. NMR analysis confirmed the structure of the product.

EXAltPLE 19 Preparation of 1-Methyl-3- ~N'-[(3'-Cyclohexyloxycar-bonyl)propyl] ~carbamoylpyridinium iodide:
The product of Example 18 (1.74 9, 6 mmol) was 5 dissol ved in a minimum amount of acetone and the re-sulting white precipitate was filtered. ~ethyl iodide (1.5 mL, 24 mmol) was added in one portion to the solution, with stirring, at 0C. The mixture was allowed to gently reflux overnight. Filtration of a 10 white precipitate and evaporation of the yellow filtrate produced a reddish oil, which was dissolved in acetone, filtered and evaporated to dryness. Anal.
c- for C22H2303N2I: C, 47.26; H, 5.79; N, 6 48;
29.38. Found: C, 47.03; H, 5.85; N, 6.44; I, 29.26.

EXA~PLE 20 Preparation of 1-Methyl-3-~N-~(3'-cyclohexylcarbonyl)-propyl~ ~carbamoyl-1,4-dihydropyridine:
The product of Example 19 (0.11 9, 0.26 mmol) was dissolved in 25 mL of ice cold deaerated water. NaHC03 (0.09 9, 4-fold excess) was added, followed by Na2S204 (0.14 9, 3-fold excess). Ethyl acetate (25 mL) was added and the mixture was stirred under nitrogen for 30 minutes. The organic layer was extracted and dried to give an orange oil that reduced methanolic silver nitrate immediately. NMR analysis confi rmed that the product had the structure:

¢~u~-~2c~2c~2~o c~3 EXA~PLE 21 Preparation of Valproic acid chloride (2-Propyl-pentanoyl chloride):
To 4.32 g (30 mmol) of valproic acid in an ice bath. thionyl chloride (3.60 9, 30 mmol) was slowly added, with stirring. The neat mixture was allowed to come to room temperature and then heated in a water bath at 50C for 30 minutes. SO mL portions of dry benzene were twice added and removed under reduced pressure. The resultant product was used in subse-quent reactions without further purification.

EXA~PLE 22 Preparation of Valproic acid 2-iodoethyl ester (2'-Iodoethyl 2-propylpentanoate):
To the product of Example 21 (4.87 g, 3n mmol), 2-iodoethanol (5.16 g, 30 mmol) was added with stirring and cooling in an ice bath. The neat mixture was then heated to 100C in a water bath for 10 minutes, then removed from the heat and stirred for an additional 10 minutes. The reaction mixture was then dissolved in 50 mL of ether, washed with water (1 x 30 mL), SX NaOH (2 x 30 mL), and again with water (2 x 30 mL). The ether layer was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. A light yellow liquid product was obtained in 67X yield from valproic acid (6.0 9). Silver nitrate gave a bright yellow precipitate. NMR analysis confirmed the identity of the product.

EXA~PLE 23 Preparation of 1-~2'-(2''-Propyl)pentanoyloxy3ethyl-3-carbamoylpyridinium iodide:
The product of Example 22 (3.28 9, 11 mmol) and 50 mL of dimethylformamide were added to nicotinamide (1.22 9, 10 mmol). The mixture was heated to reflux for 3 hours, then was cooled. Removal of solvent under reduced pressure afforded a brown oily residue, which was stirred with ether (60 mL) for 30 minutes, giving a yellow powder. ~he ether was decanted and a fresh portion of ether (50 mL) WdS added. The crude product was vacuum filtered under N2, then was recrystallized from isopropanol/ether to give 3.5 9 of the desired product (84X yield), m.p. 111-112C. The product had the formula:
~ CON}~2 ~oJ

~2C~2~C~2f~c~2c~3 C~2C~2C~3 EXA~PLE 2q Preparation of 1-~2'-(2''-Propyl)pentanoyloxy~ethyl-3-carbamoyl-1,4-dihydropyridine:
rO 50 mL of ice-cold degassed deionized water, the product of Example 23 (420 mg, 1 mmol) was added. To that solution, NaHC03 (366 mg, 4 mmol) and Na2S204 (696 mg, 4 mmol) were added, with stirring. Nitrogen gas was bubbled through the solution for 30 minutes. rhe aqueous solution ~as then extracted with ether (6 x 25 mL) until the ether layer was no longer yellow. The combined ether extracts were washed with water (1 x 50 mL) and dried over MgS04. The ether layer was decanted from the drying agent and the solvent was removed under reduced pressure. To the oily residue, ether was added and then removed (10 x 5 mL) on a vacuum pump. A foam was formed. which returned to an oil upon exposure to the atmosphere. Structure was confirmed by HMR
analysis.

EXA~PLE 25 Preparation of N-Nicotinoyltyrosine ethyl ester:
Nicotinic acid (12.3 9, 0.1 mol) was dissolved in dry pyridine (300 mL). The solution was cooled and dicyclohexylcarbodiimide (20.6 9, 0.1 mol) was added.
~fter dissolution, tyrosine ethyl ester hydrochloride (24.6 g, 0.1 mol) was added and the solution was stirred overnight. The precipitated dicyclohexylurea (DCU) was removed by filtration. Additional ~CU was removed by triturating the oil wi-th hot water. The product was purified with acetone. Calculated for C17H18N204-1/2H20: C, 63.16; H, 5.88; N, 8.66.
Found: C, 63.10; H, 5.96; N, 8.59. rhe product can also be named N-~1-ethoxycarbonyl-2-(4'-hydroxyphenyl)-ethyl]nicotinamide.

EXA~PLE 26 Preparatlon of N~ Methyl-3-pyridinium)carbonyl~-tyroslne ethyl ester iodide:
N-Nlcotlnoyltyrosine ethyl ester (20 9, 0.06 mol) was dissolved in 200 mL of acetone. A two molar excess of methyl iodine (25.6 9, 0.18 mol) was added and the mixture was refluxed for 6 hours, The solvent was removed under reduced pressure to yield the desired product as a solid form. NMR analysis confirmed the identity of the product, which had the structural formula:

~3 ~-NH-<j~l--COOC~2C~3 C~ ~ OH

and can also be named l-methyl-3-~N-[(l'-ethoxy-carbonyl)-2'-(4''-hydroxyphenyl)ethyl~carbamoyl-pyridinium iodide.

EXA~PLE 27Preparation of l-Methyl-3-~N-[(1'-ethoxycarbonyl~-2'-(4''-pivaloyloxyphenyl)ethyl]}carbamoylpyridinium trifluoroacetate:
The product of Example 26 (6 9, 0.013 mol) was dissolved in 50 mL of cold trifluoroacetic acid at 0C
in an ice bath. Pivaloyl chloride (3.14 9, 0.026 mol) was slowly added and the solution was warmed to room temperature. After 24 hours, the solvent was removed under reduced pressure. The resulting dark oil was trtturated wlth petroleum ether but no soltdtftcation occurred. Ident1ty of the product was conftrmed by NMR
analys1s. The product was dissolved in aqueous methanol (10X) and extracted wtth ethyl ether to remove a highly colored contaminant before using as the starting materidl in Example 29 below.

EX~PLE 28 Preparatton of 1-Methyl-3-~N-~(l'-ethoxycarbonyl)-2'-(4~-isobutyrylox~phenyl~ethyl]}carbamoylpyridinium tr1fluoroacetate:
The product of Example 26 (6 g, 0.013 mol) was dissolved in 50 mL of trifluoroacetic acid cooled to 0C in an ice bath. To that solution, with stirring, was slowly added isobutyryl chloride (2.77 g, 2.76 mLl. The solution was stirred overnight at ambient temperature and the solvent was removed under reduced pressure. The oil was stirred overnight with petroleum ether and then dried in vacuo, but no solidification occurred. Identity of the product was confirmed by NMR
analysis. The product was dissolved in aqueous metha-nol (lOX) and extracted with ethyl ether to remove a highly colored contaminant before using in Example 30 below.

EXA~PLE 29 Preparation of l-Methyl-3-~N-[(1'-ethoxycarbonyl)-2'-(4~'-pivaloyloxyphenyl~ethyl]~carbamoyl-1,4-dihydro-pyridine:
The product of Example 27 (4.07 9, 0.00~9 mol) was dissolved in 100 mL of 25S aqueous methanol. Nitrogen gas was bubbled through the sol~tion. To the solution, stirring in an ice bath, was then added NaHC03 (2.02 9, 0.024 mol). Ethyl ether (100 mL) was added, followed by the addition of Na2S204 (4.12 9, 0.024 mol). The yellow biphasic solution was stirred for 30 minutes, then the layers were separated and the aqueous layer was extracted twice with 75 mL portions of ethyl ether. The combined organic fractions were dried over Na2S04 and the solvent was removed under reduced pressure to afford a solid foam which was oxidized by ethanolic silver nitrate. Anal. calc. for C23H20N205 1/2H20: C, 65.23; H, 7.33. Found: C, 65.76; H, 7.28; N, 6.95.

-146- l 336498 EX~PLE 30 Preparation of 1-Methyl -3- {N-[(1'-ethoxycarbonyl)-2'-(4''-isobutyryloxyphenyl)ethyl]~carbamoyl-1,4-dihydropyridine:
The product of Example 28 (2.20 g, 0.0044 mol) was dissolved in 100 mL of aqueous methanol. The solution was cooled in an ice bath with a stream of N2 passing through it. To this solution, NaHC03 (1.11 9, 0.013Z
mol) and ether (100 mL) were added. Then, sodium dithionite (2.30 9, 0.0132 mol) was added and the solution was stirred for 30 minutes. The layers were separated and the aqueous phase was washed with ethyl ether. The combined organic layers were dried over anhydrous Na2504 and reduced in volume. The resultant orange oil was oxidized by ethanolic silver nitrate.
Identity of the product was confirmed by NMR analysis.

EXA~PLE 31 Preparation of Chloromethyl ~2S-(2a,5~,6B)]-3,3-dimethyl-7-oxo-6-~( 2 ,6-dimethoxy)benzamido]-4-thia-1-azabicycl o[3.2 .O]heptane-2-carboxylate:
To a solution of 4.02 9 (0.01 mol) methicillin sodium salt in 10 mL water and 10 mL CH2Cl2, 2.4 g sodium bicarbonate and 0.34 9 tetrabutylammonium hydrogen sulfate were added. Then, 1.9 9 (0.0115 mol 25 chloromethyl chlorosulfate dissolved in 3 mL CH2Cl2 were added with stlrring, over a S minute period, keeping the temperature below 30C. After an additlonal 30 minutes of stlrring, the organic phase was separated, washed twlce wlth water and dried over MgS04. By removing the solvent in vacuo, 4.24 9 of the desired product were obtained as a yellow solid, melting at 88-90C.

EXA~PLE 32 Preparation of Chloromethyl ~2S-(2~,5~,6B)]-3,3-dimethyl-6-(5-methyl-3-phenyl-4_isoxazolecarboxamido)-7-oxo-4-thia-1-azabicyclor3.2.0]heptane-2-carboxylate:
Substantial repetition of the procedure of Example 31 using 2.12 g (O.nO5 mol) oxacillin sodium salt with 1.2 g NaHC03, 0.17 g tetrabutylammonium hydrogen sulfate and 0.95 g chloromethylchlorosulfate afforded 1.87 g of the desired product melting at 78-80 C (dec.).

~XA~PLE 33 Preparation of Chloromethyl ~2S-(2~,5~,6~ 6-[3-(2-chlorophenyl)-5-methyl-4-isoxazolecarboxamido~-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate:
Using the same procedure as in Example 31, but substituting 2.38 g (0.005 mol~ cloxacillin sodium salt (1 ~ol water), 1.2 g NaHC03, 0.17 g 8u4NHS04 and 0.95 9 chloromethyl chlorosulfate gave 2.27 g of the desired product melting at 97-100C (dec.).

EXA~PLE 34 Preparation of Chloromethyl r2S-(2a,5a,6B)~-6-~3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo~3.2 0~heptane-2-5 carboxylate:
Similarly, following the procedure of Example 31 but using 2.55 9 (0.005 mol) dlcloxacillin Na salt (1 mol water) with 1.7 9 NaHC03, 0.17 9 8u4NHS04 and 0.95 g chloromethyl chlorosulfate, 2.43 9 of product were obtained melting at 98-101C (dec.).

EXA~PLE 35 Preparation of t(3-Pyridinylcarbonyl)oxy~methyl ~2S-(2~,5a,6B)]-3,3-dimethyl-7-oxo-6-~(2,6-dimethoxy)-benzamido]-4-thia-1-azabicyclo~3.2.0~heptane-2-carboxy-15 late:
Three and eight-tenth grams (0.0089 mol) of the methicillin chloromethyl ester produced in Example 31 and 1.6 9 (0.01 rnL) potassium nicotinate in 70 mL ~MF
were stirred 6 days at room temperature (20-25C). 300 20 mL ethyl acetate were added, the resultant solid was removed by filtration and the solution was extracted 4 times with 50 mL concentrated aqueous ~aCl and dried over MgS04. The solvent was removed in vacuo and the resultant residue was purified by chromatography 25 (silica gel). Obtained as a white solid were 3 9 of the desired product melting at 151-157C.

EXA~PLE 36 Preparation of [(3-Pyridinylcarbonyl)oxy~methyl t2S-(2a,5~,6B)]-3,3-dimethyl-6-(5-~ethyl-3-phenyl-4-isoxa-zolecarboxamido)-7-oxo-4-thia-1-azabicyclot3.2.0]-heptane-2-carboxylate:
Follo~ing the procedure of Example 35, but utiliz-ing 1.81 9 (0.004 mol) of the oxac~l1in chloromethyl ester produced in Example 32 and 0.75 9 (0.0046 mol) K
nicottnate, afforded, after purification by chromato-graphy, 0.75 9 of the desired product as a white solidmelting at 79-82C (dec.).
EXA~PLE 37 Preparation of t(3-Pyridinylcarbonyl)oxy]methyl ~2S-(2a,5a,6B)]-6-[3-(2-chlorophenyl)-5-methyl-4-isoxazole-carboxamido]-3,3 dimethyl-7-oxo-4-thia-1-azabicyclo-~3.2.0~heptane-2-carboxylate:
Using the procedure of Example 35, but substi-tuting 2.1 9 (0.0043 mol) of the cloxacillin chloro-methyl ester produced in Example 33 and 0.8 9 (0.005 mol) K nicotinate, gave 1.2 9 of product melting at 83-85C (dec.).

EXA~PLE 38 Preparation of [(3-Pyridinylcarbonyl)oxy]methyl [2S-(2~,5~,6B)]-6-[3-(2,6-dichlorophenyl)-5-methyl-4-isoxa-zolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabi-cyclot3.2.0]heptane-2-carboxylate:
Sim~larly, followtng the procedure of Example 35 but using 2.27 9 (0.0047 mol) of the dicloxacillin chloromethyl ester produced in Example 34 and 0.87 9 150_ 1 3 3 6 4 9 8 (0.0054 mol) K nicotinate afforded 1.1 9 of the product as a wh~te solid melting at 87-90C tdec.).

EXA~PLE 39 Preparation of [2S-(2~,5a,6~)]-3-~[~[3,3-Dimethyl-7-oxo-6-~(2,6-dimethoxy)benzamido]-4-thia-1-azabicyclo-[3.2.0]hept-2-yl]carbonyl~oxy]methoxy]carbonyl~-1-methylpyridinium iodide:
One and one-fourth grams (0.0024 mol) of the methicillin derivative produced in Example 35 in 35 mL
nitromethane and 1.14 9 (0.5 mL) (0.008 mol) methyl iodide were reacted in a closed system at room temperature (20-25C) for 7 days. The solvent was removed in vacuo, the resultant residue was stirred with ether, filtered off, washed with ether and dried. There were thus obtained 1.6 9 of yellow hygroscopic product melting at 95-100C and being further characterized by the structural formula:

~OHH ~S ~,<CH3 cocHzoc~) ~H3 EXA~PLE 40 Preparation of [2S-(2~,5~,6B)]-3-[[t~3,3-dime (5-methyl-3-phenyl-4-isoxazolecarboxamido)-7-oxo-4-thia-1-azabicyclo~3.2.0~hept-2-yl]carbonyl~oxy]-methoxy]carbonyl~-1-methylpyridinium iodide:
Using the procedure of Example 39, but substitu-ting 0.5 9 (0.0009 mol) of the oxacillin derivative produced in Example 36 in 25 mL nitromethane and 0.45 9 (0.2 mL) (0.003 mol) CH3I produced, after 6 days, 0.6 9 of the desired product melting at 75-80C and having the formula:

N~O~CH ~
jCOCH20lCI~ ~.

EXA~PLE 41 Preparation of [2S-(2a,5~,6B)]-3-t[[[~6-[3-(2-Chlr phenyl)-5-methyl-4-isoxazolecarboxamido]-3~3-dimeth 7-oxo-4-thia-1-azabicyclo[3.2.0~hept-2-yl]carbonyl]-oxy]methoxy]carbonyl]-1-methylpyridinium iodide:
Similarly, using the procedure of Example 39, but substituting 0.44 g (0.0008 mol) of the cloxacillin derivative produced in Example 37 in 25 mL nitromethane and 0.45 9 (0.2 mL) (0.003 mol) CH3I, gave 0.45 9 of product melting at 90-95C (dec.) and having the formula:

~`o~ a3 llttH20n~ ~_ EXA~PLE 42 Preparation of ~2S-(2~,5~,6~)-3-[~ 6-~3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-yl]-carbonyl]oxy]methoxy]carbonyl]-1-methylpyridinium iodide:
In a similar manner, using the procedure of Example 39, but substituting 0.5 g (0.007 mol) of the dicloxacillin derivative produced in Example 38 in 25 mL nitromethane and 0.45 g (0.2 mL) (0.003 mol) CH3I
gave 0.55 g of product melting at 95-100C (dec.) and having the formula:

~O~t; ~ _ 3 1,~ioCH2o~

Cl 3 t 336498 ~ XA~PLE 43 Preparation of ~[(1,4-Dihydro-l-methyl-3-pyridinyl)-carbonyl~oxy3methyl ~2s-(2~5a~6~)]-3~3-di~ethyl-7 6-r(2~6-dimethoxy)benzamido]-4-thia-l-azab [3.2.0]heptane-2-carboxylate:
0.45 9 (0.0007 mol) of the product of Example 39 dissolved in a mixture of deaerated 25 mL ethyl acetate and 70 mL water were reduced with a mixture of 0.34 9 (0.004 mol) NaHC03 and 0.48 9 (0.0028 mol) sodium dithionite at 0-5C over 70 minutes. rhe disappearance of the 268 nm maxima and increase of 366 nm maxima in the U.V. spectra were followed. The layers were separated and the aqueous layer was extracted with 2 x 25 mL ethyl acetate, then the organic layers were extracted with 2 x 20 mL cold, deaerated water. After drying over Na2S04, the solvent was removed in vacuo.
0.25 9 of the product was obtained as a yellow solid melting at 88-90C (dec.). The product had the formula:

~OCH3 ~ ~ ~5 ~<CH

COCH20C--¢;3 EXA~PLE 44 Preparation of tt(1,4-Oihydro-l-methyl-3-pyridinyl)-carbonyl~oxy3methyl t2S-(2~,5a,6B)]-3,3-dimethyl-6-(5-methyl-3-phenyl-4-isoxazolecarboxamido)-7-oxo-4-thia azabicyclo[3.2.0]heptane-2-carboxylate:
Similarly, repetition of the general procedure of Example 43 using 0.17 9 (0.00025 mol) of the product of Example 40, 0.08 9 (0.0001 mol) NaHC03 and 0.51 9 (0.001 mol) Na2S204, in 15 mL water and 15 mL ethyl acetate, afforded 0.1 9 of product melting at 93-100C
tdec.). The product had the formula:

I ,~ CONH ~3~H3 N~o 3 o jCOCH2C ¢3 I

CHl EXA~PLE 45 Preparation of tt(1,4-Dihydro-1-methyl-3-pyridinyl)-carbonyl~oxy]methyl ~2S-(2~,5~,6B)]-6-[3-(2-chlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo~3.2.0]heptane-2-carboxylate:
In a similar manner, following the procedure of Example 43, but substitut1ng 0.18 9 (0.00025 mol) of the product of Example 41, 0.089 NaHC03 and 0.17 9 Na2S204, gave 0.13 9 of product as a yellow solid, melting at 80-85C (dec.) and having the structural formula:

~5 ~<CH3 CH3 o N--COCH20C ~3 I

EXA~PLE 46 Preparation of ~(1,4-Dihydro-l-methyl-3-pyridinyl)-carbonyl]oxy]methyl ~2S-(2a~5a~6g)]-6-~3-(2~6-dichloro-phenyl)-5-methyl-4-isoxazolecarboxamido]-3~3-dimeth 7-oxo-4-thia-1-azabicyclo~3.2.0]heptane-2-carboxylate:
~n like manner, repetition of the procedure of Example 43 using n.19 9 (0.00025 mol) of the product of Example 42, 0.08 9 Na~C03, 0.17 9 Na2S204 yielded 0.14 g of desired product melting at 98-102C (dec.) and having the formula:

0CH201C1 ~3 EXA~PLE 4~
Preparatton of [(3-Pyrtdinylcarbonyl)oxy]methyl [2S-(2a~s~6B)]-3~3-dimethyl-7-oxo-6-[(phenylacetyl)amino]
4-thta-1-azabtcyclot3.2.0]heptane_2_carboxylate:
A suspension of 3.83 9 (0.01 mol) of the chloro-methyl ester of benzylpenicill~n, namely chloromethyl [2S-(2~,5~,6B)]-3,3-dimethyl-7-oxo-6-[(phenylacetyl)-amino]-4-thia-l-azabicyclo~3.2.0]heptane-2-carboxylate~
and 1.93 9 (0.012 mol) potassium pyridine-3-carboxylate in 100 mL of dimethylformdmide was stirred at 20-25C
for 6 days. Then, 300 mL of ethyl acetate were added and the solid was removed by filtration. The solution was extracted 4 times with concentrated aqueous sodium chloride solution, then dried over MgS04. The solvent was removed in vacuo to give 4.5 9 of foamy solid.
Purification by chromatography over silica gel using ethyl acetate as eluent afforded ~.5 9 of product melting at 127-130C.

EXA~PLE 48 Preparation of [2S-(2~,5~,6~)]-3-[~[[~3,3-Oimethyl-7-oxo-6-~(phenylacetyl)amino]-4-thia-1-azabtcyclo~3.2.0]-hept-2-yl]carbonyl]oxy]methoxy]carbonyl]-1-methyl-pyridinium iodide:
Two and one-half grams (0.053 mol) of the product of Example 47 dissolved in 100 mL of dry nttromethane were reacted wtth 2.25 9 (1 mL, 0.016 mol) of methyl todtde tn a closed system at 20-25C for 6 days. at the end of whtch ttme thtn layer chromatography sho~ed complete reactton. The solvent was removed tn vacuo and the soltd residue was slurrted wtth ether, ftltered and dried in vacuo over P205. The product, melting at 90-95~C (dec.), was obtained as a yellow solid (2.91 9). It was asslgned the structural formula:

I s C6H5CH2C~IH ~/ \~ C~3 ~/\ CH3 IlOCH2 ~
O O tl S EXA~PLE 49 Preparation of [[(1,4-Oihydro-1-methyl-3-pyridinyl)car-bonyl]oxy3methyl [2S-(2a,5~,6 ~) ]-3,3-dimethy1-7-oxo-6-~tphenylacetyl)amino~-4-thia-1-azabicyclor3.2.0~hep-tane-2-carbo%ylate:
The quaternary salt prepared in Example 48 (3.25 9, 0.0053 mol~ was dissolved in a mixture of 350 mL of water and 150 mL of ethyl acetate. The resultant mixture was cooled at 0-5C and deaerated with nitrogen, then a mixture of 2.67 9 (0.032 mol) of sodium bicarbonate and 3.69 9 (0.021 mol) of sodium dithionite was added over a 2-3 minute period. The reaction mixture was st1rred for 1 hour under the same conditions as before, then the layers were separated, the aqueous layer WdS extracted twice with 50 mL
portions of ethyl acetate, and the combined organic extracts were washed twice with 30 mL port~ons of cold, deaerated water. Dry1ng over sod~um sulfate and removal of the solvent in vacuo afforded 1.7 9 of yellow solid melting 98-100C and having the formula:

C6HSCH2CNH ~/ ~< CH3 o , CH3 Il H2011 ~3 O O N

EXA~PLE SO
Preparation of Chloromethyl N-[3-(10,11-dihydro)-5H-dibenz~b,f~azepin-S-yl)]propyl-N-methylcarbamate:

5 Method A:
Desipramine hydrochloride (1.5 9, 0.005 mol) was dissolved in 20 mL of methylene chloride, cooled at 0-5C. Then 1 9 NaHC03 was added, followed by 0.92 9 (0.007 mol) chloromethyl chloroformate. The reaction mixture was stirred for 1 hour, then the salts were removed by filtration and the solution was extracted twice with 10 mL portions of 5X HCl. The organic layer was dried over ~gS04 and the solvent was removed in vacuo to give the desired compound as a colorless oily substance in 76~ yield (1.35 9).

Method B:
Imipramine hydrochloride (1.59 9, 0.005 mol) was dissolved in 15 mL of water, then 5 mL of 4X sodi~m hydroxide solutton was added, with cool~ng. The resultant ~mipramine base was extracted twice with 10 mL portions of benzene. The solut~on was concentrated -159- l 3 3 6 4 9 8 to 10 mL, then a solutlon of 0.7 g (0.0054 mol) chloro-methyl chloroformate in 5 mL benzene was added with cool1ng at 10C. The reaction mixture was stirred at 20-25C for 30 minutes, then was refluxed for 1 hour.
A small amount of imipramine hydrochloride resulted and was f11tered off. The solution was extracted twice with 20 mL portions of 45 HCl and dried over MgS04.
Removal of solvent in vacuo afforded 1.2 9 (66S) of product having the same characterist1cs as that obtained by Method ~.

EX~PLE 51 Preparation of l-Chloroethyl N-[3-(10,11-dihydro-5H-dibenz[b,f~azepin-5-yl)]propyl-N-methylcarbamate:
Following the general procedure of Example 50, but using l.S 9 (0.005 mol) of desipramine hydrochloride and 0.86 9 (0.006 mol) chloroethyl chloroformate and carrying out the reaction at 5-10C for 2 hours, gave 1.6 9 (86~) of the title compound as a colorless oil.

EXA~PLE 52 Preparation of ~N-~3-(lO,ll-Dihydro-5H-dibenz[b,f]-azepin-S-yl~]propyl-N-methylamino~carbonyloxy]methyl 3-pyridinecarboxylate:
The product of Example 50 (1.35 9, n.oo37 mol) d1ssolved in 5 mL dimethylformamide was added to a solution prepared from 0.57 g (0.046 mol) nicotinic acid and 0.45 9 trtethylamine in 5 mL dimethyl-formam1de. The m1xture was st1rred for 24 hours at 25-30C, then 30 mL of ethyl acetate were added. The precip1tated salts were removed by filtration and the -160- l 3 3 6 4 9 8 solution was extracted 4 times with 15 mL portions of saturated aqueous sodium chloride solution. Drying over MgS04 and removal of the solvent in vacvo afforded l g (61~) of pure product as an oil.

EXA~PLE 53 Preparation of ~l-{N-~3-(lO,ll-Dihydro-5~-dibenz~b,f~-azeptn-5-yl)]propyl-N-methylamino~carbonyloxy]ethyl 3-pyridinecarboxylate:
Following the general procedure of Example 52, but using 1.05 9 (0.0028 mol) of the product of Example 51, 0.45 9 (0.036 mol) of nicotinic acid and 0.36 9 of tri-ethylamine in 10 mL dimethylformamide and carrying out the reaction at 25-30C for 48 hours, gave 0.5 9 of the title compound as a yellow oil.

EXA~PLE 54 Preparation of 3-[ {N-t3-(10,11-Dihydro-5H-dibenz[b,f]-azepin-5-yl)]propyl-N-methylamino}carbonyloxy]methoxy-carbonyl-l-methylpyridinium iodide:
Eight-tenths gram (0.0018 mol) of the product of Example 52 in 30 mL of nitromethane was methylated with 0.8 mL of methyl iodide at 25-30C ~or 48 hours. The solvent was removed ~n vacuo and the residue was slurried with ethyl ether, filtered and dried over P205. The quaternary salt was obtained in 83X yield (0.88 9) as a light yellow sol~d melting at 172-175C
(dec.) and having the structural formula:

C~ruf ~

EXA~PLE 55 Preparation of 3-[1-~N-[3-(10,11-Oihydro-SH-dibenz-tb,f]azepin-5-yl)]propyl-N-methylamino~carbonyloxy]-ethoxycarbonyl-l-methylpyridinium iodide:
Following the general alkylation procedure of Example 54, but using O.S g (0.0011 mol) of the product of Example 53 in 15 mL nitromethane with O.S mL methyl iodide, and carnying out the reaction at 20-25C for 6 days, afforded 0.33 9 (SO~) of the desired quaternary salt as a dark ye110w solid melting at 101-103C (dec.) and having the structural formula:

~<Ch3 ~3 EXA~PLE 56 Preparation of t~N-~3-(lO,ll-Dihydro-SH-dibenz~b,f~-azepin-5-yl)]propyl-N-methylamino~carbonyloxy]methyl 1,4-dihydro-l-methyl-3-pyridinecarboxylate:
Three-tenths gram (O.OOOS mol~ of the product of Example 54 in 30 mL water and 15 mL ethyl acetate was reduced with n.25 9 (0.003 mol) NaHC03 and 0.35 9 (0.002 mol) sodium dithionite at 0-5C, wtth deaera-tion, for a 60 minute period. The layers were separated and the aqueous layer was extracted twice with 30 mL portions of ethyl acetate. The combined organic layers were then extracted twice with 20 mL
portions of cool deaerated water. Drying over Na2S04 and removal of the solvent in vacuo afforded 0.22 9 (95X) of the title compound, melting at 59-63C (dec.) and having the structural formula:

~3 o EXA~PLE 57 Preparation of [1-{N-[3-(lO,ll-Oihydro-SH-dibenz~b,f]-20 azepin-5-yl)]propyl-N-methylamino~carbonyloxy~ethyl l,4-d~hydro-1-methyl-3-pyridinecarboxylate:
Following the procedure of Example 56, but us~ng 0.1 9 (0.0017 mol) of the product of Example 55 ~n lO
mL water and 6 mL ethyl acetate, 0.11 9 NaHC03 and O.lS

g Na2S204 and carring out the reaction for a 60 minute pertod, gave 0.07 9 (88S) of the title compound as a yellow solid, melting at 60-65C ~dec.) and having the structural formula:

~ o fH3 o ~ COCHOC~
c~r~rU~ ~c~
c"3 EXA~PLE 58 Preparation of N-(2-Hydroxyethyl)-3-pyridinecarboxa-mide:
A solution of 49.2 g (0.32525 mol) ethyl nico-tinate and 72 9 (1.17 mol) ethanolamine was heated at 70C for 60 hours. The excess ethanolamine was removed under reduced pressure and the resulting viscous cream oil was stirred with ether for 48 hours. The resulting white solid was removed by filtration, affording 46 9 (85.1S) of the title compound melting at 75-78C.

EXA~PLE 59 Preparation of 3-[2'-(2"-propyl)pentanoyloxy]ethylcar-bamoylpyridine:
To a sttrred solutton of 1.0 9 (0.006021 mol) of the product of Example 58 and 0.61 9 (0.00598 mol) tri-ethylamtne in 40 mL dry dtchloromethane, 1.96 9 (0.012047 mol) of (2-propyl)pentanoyl chloride were added and the mixture was refluxed for 4 hours. rhe resultant solution was washed sequentially with 30 mL
5S NaHC03, 30 mL SX HCl and 30 mL water. The organic layer WdS dried over MgS04 and the solvent was removed under reduced pressure to give 0.6 9 (34.3X) of the product as a pale brown oil.

EXA~PlLE 60 Preparation of l-Methyl-3-t2'-(2~-propyl)pentanoyloxy]-ethylcarbamoylpyridinium iodide:
To a solution of 1 9 (0.00342 mol) of the product of Example 59 in 20 mL of dry ethyl acetate, 0.73 9 (0.00513 mol) of methyl iodide was added. The reaction mixture was stirred overnight at room temperature. The pale yellow solid which formed was removed by filtra-tion and recrystallized from ethyl acetate to give 1.35 9 (90.9X) of the quaternary salt as a yellow crystal-line solid. The product had the formula:

~ NHCH2CH20C-cH(cH2cH2c~)2 as confirmed by IR, NMR and UV analyses.

1 33649~

EXA~PLE 61 Preparation of 1-Methyl-3-[2~-(2~-propyl)pentanYlXY]~
ethylcarba~oyl-1,4-dihydropyri di ne:
To 50 mL of vigorously stirred, degassed, ice-cold deionized ~ater, a solution of 3.0 9 (0.006909 mo~) of the quaternary product of Example 60 in 50 mL of ethyl acetate was added. Throughout the reaction, the temperature and pH were maintained at 0C and 8 respectively, while nitrogen was bubbled through the reaction mixture. A mixture of 3.5 9 ~0.04145 mol) of sodium bicarbonate and 4.8 9 (0.02163 moll of sodium dithionite was ddded portionwise. After 45 minutes, the organic layer was separated and the aqueous layer was extracted with 100 mL of ice-cold ethyl acetate.
~he combined organic extracts were washed with ice-cold water and dried over ~gS04. Solvent was removed under reduced pressure to give 2.1 9 (98.8~) of the product as a pale yellow solid having the structural formula:

n O
¢~ ``NHCH2CH20C-CH(cH2cH2cH3)2 as confirmed by IR, NMR and UV analyses.

EXA~PLE 62 Preparatton of 3-Pyridinecarboxylic acid (2-hydroxy)-ethyl ester hydrochloride:
To 120 mL cold (-10C) ethylene glycol, 16 mL of thionyl chloride were added dropwlse. Upon completion of the addition, 24.6 9 (0.2 mol) of nicotinic acid were added portionwise and the reaction mixture was heated overnight at 60C. rhen, 700 mL of hot tetra-hydrofuran were added and the mixture was cooled. The solid which formed was removed by filtration and washed with ether to give 28.5 9 of the title compound as white crystals.

EXA~PLE 63 Preparation of 3-~2'-(2U-Propyl)pentanoyloxy]ethoxy-carbonylpyridine:
To a solution of 10.0 9 (0.0491 mol) of theproduct of Example 62 in 150 mL of dry CH2C12, 10.7 9 (0.09819 mol) of triethylamine were added. After all of the solid was dissolved, 11.92 9 (0.07364 mol) of 2-propylpentanoyl chloride were added and the reactionmixture was stirred at room temperature for 36 hours.
Sequential washing with 5~ NaHC03, 5X HCl and water afforded an organic layer which was then dried over anhydrous ~gS04. Solvent was removed under reduced pressure to give a yellow-brown oil that was triturated with a 40:60 mixture of ether and petroleum ether to yield 9.7 g of the product as an orange oil.

EXA~PLE 64 Preparat1On of l-Methyl-3-~2'-(2~-Propyl)pentanoyloxy]-ethoxyearbonylpyr1d1nium iodide:
To a solutlon of 2.0 9 10.006816 mol) of the product of Example 63 in 10 mL of dry acetone, 1.45 9 (0.01022 mol~ of methyl iod1de were added and the mixture was refluxed overnight. Removal of solvent under reduced pressure afforded 1.84 9 of the quater-nary salt as a brown o11. The product had the struc-tural formula:

r~ cH(c~;crl1~ C~1~)2 EXA~PLE 65 Preparation of l-Methyl-3-t2'-(2"-propyl)pentanoyloxy]-ethoxycarbonyl-1,4-dihydropyridine:
To 50 mL of vigorously st~rred, degassed, ~ce-cold deionized water, a solution of 1.84 9 (0.004226 mol) of the quaternary product of Example 64 in 50 mL of ethyl acetate was added. Throughout the reaction, the temperature and pH were maintained at 0C and 8, respect1vely, while argon was bubbled through the reaction mixture. A mlxture of 2.13 9 (0.02536 mol) of NaHC03 and 2-94 9 (0.0169 mol) of ~a2S204 was added port1On~1se. After 55 mtnutes, the organ1c layer was separated and the aqueous layer was extracted with 100 mL of ice-cold ethyl acetate. The comblned organic layers were washed with ice-cold water and dried over MgS04. The solvent was re~oYed under reduced pressure to give 0.9 9 of the tttle compound as a yellow oil.
The product had the formula:

~r~ ~(CH2~2~H3)2 IExA~pLE 66 Preparation of 3,17~-Bis~(3-pyridinylcarbonyl)oxy~-19-nor-17a-pregna-1,3,5(10)-trien-20-yne:
To 2.0 9 (6.7 mmol) of ethinyl estradiol dissolved in 50 mL of dry pyridine were added 6.16 9 (0.027 mol) of nicotinic anhydride and a catalytic quantity of 4-(dimethylamino)pyridine (OMAP). The solution was warmed gently to 50C to effect solution. After 2 weeks, the pyridine solution was poured over ice and the solid produced was collected by filtration. The solid was dried over P205 in vacuo to give 3 9 (85~) of an off-white powder.

EXA~PLE 67 Preparation of 3-Hydroxy-17B-t(3-pyridinylcarbonyl)-oxy]-19-nor-17a-pregna-1,3,5(10)-trien-20-yne:
To 200 mL of O.5X methanolic KHC03, 2.0 g (3.9 mmol) of the product of Example 66 were added. After 6 hours, the slurry WdS d~luted with 200 mL of water and the m1xture was extracted w1th chloroform. The organic layers were combtned, dr1ed over MgS04 and concentrated tn vacuo. The result1ng o11 was triturated with hexane to g1ve 1.48 9 (94X) of a wh~te solid. NMR and UV
spectra and elemental analysis conf1rmed the identity of the t1tle compound.

EXA~PLE 68 Preparation of l-Methyl-3-~[(19-nor-17~-pregna-l~3~s(lo)-trien-2o-yn-l7B-yl)oxy]carbonyl~pyridinium iodide:
To S0 mL of acetone, 1.0 9 (2.5 mmol) of the product of Example 67 was added, followed by 2 mL of methyl iodide. The react~on mixture was refluxed for 12 hours. The solid which formed was collected by filtration, yielding 1.15 9 (85X) of the quaternary salt as a yellow solid having the structural formula o ~

~ ~-C~CH

110~
The assigned structure was conf1rmed by UV and NMR
spectral analyses and by elemental analysis.

- 1 7 o -EXA~PLE 69 Preparat10n of 3-Hydroxy-17B-{~(l-methyl-l,4-d1hydropyridin-3-yl)carbonyl]oxy~-19-nor-l7~-pregna-1,3,5(10~-trien-20-yne:
To a cooled suspension of 1.0 9 (1.8 mmol) of the product of Example 68 in 100 mL of 50:50 water: tert-butanol, 0.77 9 of NaHC03 and 0.96 9 of Na2S204 were added. The reaction m1xture was st~rred at 0C for l hour, then was extracted twice with lO0 mL portions of CH2Cl2. The organic extracts were combined, dried over ~gS04 and concentrated under reduced pressure to give 520 mg (69X) of the title compound as a yellow foam.
The product was ass1gned the structure o ~CH3 ~ CH

HO

which was in accord with UV and N~R values as well as elemental analysis.

EXA~PLE 70 Preparation of 3,17B-Bis[(3-pyridinylcarbonyl)oxy]-estr~-1,3,5(10)-trtene:
To 5.3 9 (0.03 mol) of nicotinoyl chloride in 30 S mL of dry pyridine at 0C were added 2.0 9 (0.0073 mol) of ~-estradiol. The reaction mixture was refluxed for 1 hour, then was poured over 100 mL of ice water, and the resulting precipitate was collected by filtra-tion. The precipitate was dried ln vacuo over P205, affording 3.18 9 (90%) of the title compound melting at 148-150C.

EXA~PLE 71 Preparat10n of 1,1 ' -Oimethyl-3,3'-~t(estra-1,3,5(10)-triene-3,17B-d1yl)dioxy]dicarbonyl~dipyridinium dliod1de:
To 50 mL of acetone and 2 mL (0.032 mol) of methyl iodide, 2.0 9 (0.004 mol) of the product of Example 70 were added. The solution was heated at reflux overn19ht. The precipitate which formed was filtered, washed with acetone and dried to give 2.75 9 (88X) of the quaternary salt melting at 251-252C and having the structural formula / h3 C~ ~

as conf1rmed by UV, NMR and elemental analyses.

EXA~PLE 72 Preparation of 3,17B-8is¦~(1-methyl-1,4-dihydropyridin-3-yl~carbonyl]oxy~estra-1.3,5(10)-triene:
One gram (1.31 mmol) of the product of Example 71 was dissolved in 100 mL of dry acetonitrile. To that solution, whtch was flushed with n~trogen, 0.28 9 (1.31 mmol) of l-(phenylmethyl)-4-(aminocarbonyl)-1,2-d1hy-dropyridine was added, and the reactton mixture was stirred at 0C for 1 hour. Removal of the solvent under reduced pressure afforded a solid, which was suspended in methylene chloride and removed by filtration. The filtrate was chromatographed several times on a neutral alumtna column prepared with methylene chloride. Purification and evaporation of the solvent in vacuo gave a solid foam. The product had the formula as confirmed by UV, NMR and elemental analyses.

EX~PLE 73 Preparation of 3-(Phenylcarbonyloxy)_l7g_~(3-pyridinyl-carbonyt)oxy]estra-1,3,5(10)-triene:
Estradiol benzoate (2.5 9, 6.6 mmol) was dissolved in S0 mL of dry pyridine, then 1.66 9 of nicotinic anhydride and a catalytic amount of 4-(dimethylamino)-pyridine (DMAP) were added. The reaction mixture was stirred for S days at room temperature, then was poured into ice water. The solid wh~ch formed was collected by filtration and dried in vacuo, yielding 3.01 9 (94X) of the product as a white solid melting at 151-154C.

EXA~PLE 7~
Preparation of 1-Methyl-3-(~r3-(phenylcarbonyloxy)-estra-1,3,5(10)-trien-17B-yl]oxy}carbonyl)pyridinium iodide:
The product of Example 73 (1.5 g, 3.1 mmol) was suspended in 2.5 mL of acetone. Then, 2 mL of methyl iodide were added and the reaction mixture was refluxed overnight. The yellow solid (1.8 9, 93S) was collected by filtration and dried in vacuo. UV, NMR and elemental analyses confirmed that the product had the assigned structure:
~CH3 f o~V

-174- l 3 3 6 4 9 8 EXA~PLE 75 Preparat10n of 3-(Phenylcarbonyloxy)-17~-~[1-methyl-1,4-d1hydropyrid1n-3-yl)carbonyl~oxy~estra-1,3,5tlO~-triene:
The quaternary salt prepared in Example 74 (1.2 9, 1.93 mmol) was suspended in 100 mL of S0:50 tert-butyl alcohol/water. Then, 0.81 9 of NaHC03 and 1.0 9 of Na2S204 were added and the react10n was allowed to continue for 1.5 hours. The resultant solut10n was extracted with CH2C12, and the organic phase was dried over MgS04 and concentrated in vacuo to afford 650 mg of title compound as a yellow foam. ~he identity of the product was conf1rmed by UV, NMR and elemental analyses. It was ass19ned the structure:

~3 ~ ~H~

EXA~PLE 76 Preparation of N-(2-~4-~Bis(2-chloroethyl)amino]-butanoyloxy~ethyl)-3-pyridinecarboxamide:
Chlorambucil (2n 9, 0.0657 mol) was dissolved in 800 mL of dry acetonitrtle, then 13.1 9 (0.079 mol) of H-(2-hydroxyethyl)-3-pyr~d1necarboxamide were added.
Aceton1tr11e was added unt11 the solut10n was clear.
The total volume of acetonitrile used at this stage was 850 mL. To the stirred solution, maintained over argon, there were added 1.492 g (0.0723 mol) of di-cyclohexylcarbodiimide and 0.802 9 (0.0066 mol) of 4-(dimethylamino)pyridine (DMAP). The reaction mixtùre was stirred overnight at room temperature under dry conditions, and the progress of the reaction was followed by thin layer chromatography. At the end of the reaction period, the solid which formed was removed and washed with 50 mL of cold acetonitrile. The filtrate was evaporated in vacuo at 30C, and the yellow solid thus obtained was dissolved in a minimum amount (15 mL) of 8:2 chloroform/tetrahydrofuran and applied to a column packed with 900 9 of silica gel.
The column was eluted with 8:2 chloroform/tetrahydro-furan. The adduct and chlorambucil were eluted withinthe first 500 mL, and the desired ester was then collected upon evaporation of the eluent under vacuum. The title compound was obtained in 82.7X yield as a yellow solid melting at 73-75C. It had the formula (C~CH2CH2)2N~(CH2)3-C-OCHZCH2HHC~

Preparation of 1-Methyl-3-[(N-{2-[4-(~4-bis(2-chloro-ethyl~amino~phenyl~butanoyloxy]ethyl~)carbam pyridinium methanosulfate:
S The product of Example 76 (2 9, 0.04 mol) was dissolved in 200 mL dry acetonitrile. Dimethyl sulfate (0.613 9, 0.0486 mol) was added and the mixture was refluxed overnight. The reaction was followed by thin layer chromatography (8:2 chloroform/tetrahydrofuran) until no more unquaternized ester remained. Evapora-tion of the solvent in vacuo gave a residue which was washed several times with dry ether. The red viscous liquid which remained was stored over argon for further use. Yield 97.35X. The product was identified as the desired quaternary salt by NMR analysis. It was assigned the structural formula:

C 1 CHzCH2 )2N~( CH2 ) 3 -C -OCHzCH2NHC ~) Preparation of 1-Methyl-3-[(N-{2-[4-(~4-[bis(2-chloro-ethyl)]amino}phenyl~butanoyloxy~ethyl~)carbamoyl~ 4dihydropyridine:
The quaternary salt prepared in Example 77 (2.49 9, 0.0043 mol) was dissolved in 350 mL of water.
~ltrogen was bubbled through the solution throughout the reaction period. The aqueous solution was cooled -177- l 3 3 6 ~ 9 8 over ice to 5C, then ~.17 9 (0.026 mol) of NaHC03 were added over a 5 minute period, followed by 2.997 9 (0.017 mol~ of sodium dithionite over a lO minute period. The reaction mixture was maintained at 5C for 120 minutes, then the layers were separated. The aqueous layer was extracted 4 times with ethyl acetate. The ethyl acetate extracts were combined, dried over ~gS04 and evaporated to dryness in vacuo.
The semi-solid thus obtained was washed several times iO with dry ether to give the title compound as a yellow solid melting at 90-92C and having the structural formula:

2CH2)2N ~ ~ (c~12)3-c-ocH2cH2tlHc~3 EXA~PLE 79 Preparation of N-(4-~ydroxycyclohexyl)-3-pyridinecar-boxamide:
Trans-4-aminocyclohexanol hydrochloride (5.05 g, n .o33 mol) was suspended in 50 mL of ethanol, then 33 mL of lN NaOH were added slowly while cooling the reaction mixture to 10C. The homogeneous mixture was evaporated to dryness, then three portions of a 50:50 mixture of ben2ene and acetone were added and evaporated to dryness in vacuo each time. The dry solid was extracted with 100 mL of chloroform and filtered, and the filtrate was evaporated to dryness.
The residue was triturated with ether and dried to give 3.50 9 (91.23Z) of the free aminotyclohexanol melting at 111-112C.
Nicotinic acid (2.14 9, 0.017 mol) was suspended in 75 mL of dry tetrahydrofuran, then 1.76 9 of freshly distilled triethylamine were added, The clear solution thus obtained was cooled to -4C in an ice bath under argon, then ethyl chloroformate (1.88 g, 0.014 mol) in 10 mL of tetrahydrofuran was added such that the temperature did not go above 0C. The free aminocyclohexanol (2.0 9, ~.017 mol) was added dS a powder to the cold reaction mixture, which was allowed to come to room temperature and stirred for 2 hours.
~he precipitate which formed was collected by filtration, dissolved in 28 mL of hot water and recrystallized as 3.25 9 (85X) of fine colorless needles melting at 208-210C and having the formula HC~I
~C~
HIIC~

as confirmed by elemental analysis.

Preparation of N-~4-~4-(~4-[Bis(2-chloroethyl)]amino~-phenyl~butanoyloxy]cyclohexyl~-3_pyridinecarboxamide:
Chlorambucil (1.38 9, 0.0045 mol) and ~-(4-hydroxycyclohexyl)-3-pyridinecarboxamide ( 1.1 9, O.0049 mol) were mixed together with 1.03 9 (0.00459 mol) of dicyclohexylcarbodiimide and 55 mg (0.00045 mol~ of 4-(dimethylamino)pyridine (DMAP) in 50 mL of freshly disttlled dcetonitrile. The reaction mixture was stirred at room temperature in the presence of argon for 2 days. The progress of the reaction WdS followed by thin layer chromatography using 8:2 chloro-form/tetrahydrofuran. At the end of the reaction period, the precipitate was removed by filtration and the filtrate was evaporated to dryness ~n vacuo at low temperature. The residue was applied to a silica column and eluted with 8:2 chloroform/tetrahydrofuran.
The appropriate eluting portions were combined and evaporated to dryness ln vacuo. The product (1.86 9, 81X) was obtained as a light cream-colored powder melting at 120-122C and having the formula (ClCH2CH2)2~ ~ (CH2)3-~C-HNC~

The identity of the product was confirmed by elemental analysis.

---180- l 3 3 6 4 9 8 EXA~PLE 81 Preparation of l-Methyl-3-(N-~4-t4-(4-{~bis(2-chloro-ethyl~]amino~phenyl)butanoyloxy]cyclohexyl~carbamoyl)-pyridinium methanosulfate:
The product of Example 80 (1 9, 0.0019 mol) was dissolved in 30 mL of dry acetonitrile and 0.249 9 (0.0019 mol) of dlmethyl sulfate was added. The mixture was refluxed under argon until thin layer chromatography (8:2 chloroform/tetrahydrofuran on silica) indicated quaternization was complete (about one and one-half days). The solvent was evaporated in vacuo, leaving an orange residue which was washed several times with anhydrous ether and evaporated in vacuo. The quaternary salt (1.04 9, 80.6X) was obtained as a sticky yellow mass. It had the structural formula:

(ClCH2C~12)2~ ~ (CH2)3-~C

C~3 EXA~PLE 82 Preparation of l-Methyl-3-(N-~4-~4-(4-{~bis(2-chloro-ethyl)]amino}phenyl~butanoyloxy]cyclohexyl~carbamoyl~-1,4-dihydropyridine:
The quaternary salt prepared in Example 81 (0.34 9, 0.0005 mol) was dissolved in 0.5 mL of acetonitrile and taken up in 20 mL of degassed water (bubbling N2) cooled to 0C. To the stirring solution, sod1um -bicarbonate (0.27 9, 0.003 mol) was added, followed first by 0.37 9 (0.002 mol) of sodium dithionite and then by 20 mL of ethyl acetate. After 90 minutes, the organic phase was removed and the aqueous phase was extracted 3 to 4 times with ethyl acetate. rhe ethyl acetate extracts were combined, dried over sodium sulfate and evaporated in vacuo. The residual solid was washed several times with anhydrous ether and dried. rhe residue thus obtained was applied to a neutral alumina column and eluted with chloroform under pressure. Evaporation of chloroform left O.lR 9 (6~) of a hygroscopic yellow solid of the formul d ClCHZCH2 ~(CH2)3 C O

NHC~) c~3 rhe identtty of the product was confirmed by UV
analysis.

EXA~PLE 83 Preparation of N-(2-Hydroxy)propyl-3-pyridinecarboxa-mide:
To 4.29 9 (0.039 mol) of nicotinic acid suspended in 120 mL of dry tetrahydrofuran, 4.04 9 (0.039 mol) of freshly d~st~lled triethylam~ne was added in one portion. ~he resultant clear solution was cooled to -4C in an ice bath under argon. Ethyl chloroformate (4 33 9, 0.039 mol~ in 25 mL of tetrahydrofuran was added at such a rate that the temperature of the solu-tion did not exceed 0C. Then, 3 9 (0,039 mol) of 1-amino-2-propanol were added directly to the cold reaction mixture. The reaction mixture was a11Owed to come to room temperature and stirred for 2 hours. The precipitate was removed by filtration and the filtrate was evaporated in vacuo. The oily residue was washed several times with anhydrous ether and allowed to stand. The title compound was obtained as a white, hygroscopic, low-melting, waxy solid melting at 40C
(6.11 9, 85~) and having the formula ~, e -NHCH2CHOH

EXA~PLE 84 Preparation of N-{2-[4-(~4-[Bis(2-chloroethyl~]amino~-phenyl~butanoyloxy]propyl~-3-pyridinecarboxamide:
Chlorambucil (1.0 9, n.003 mol) and ~-(2-hydroxy)-propyl-3-pyridinecarboxamide (0.065 9, 0.0036 mol) were combined with 0.68 9 (0.003 mol) of dicyclohexylcarbo-diimide and 41 mg (0.0003 mol) of 4-(dimethylamino)-pyridine (DMAP) in 40 mL of freshly distilledacetonitrile. The reactton mixture was stirred at room temperature in the presence of argon for 2 days, the progress of the reactton betng followed by th1n layer chromatography on siltca ustng 8:2 methylene chlo-rtde/ethyl acetate, At the end of the react~on pertod, the precipitate was re~oved by filtration and the filtrate was evaporated to dryness ~n vacuo at 30C.
The residue was applied to a silica column and eluted with 8:2 methylene chloride/ethyl acetate. The S appropriate eluting portions were combined and evaportted to dryness in vacuo. The title compound was obtained as a sticky material in 84X yield (1.53 9).
It had the structural formula:

( C 2 C H~ ) 2H ~ ( CH2 ) 3 - COCHCH2 NHC ~O~

EXA~P~ 85 Preparation of 1-Methyl-3-~(N-~2-~4-({4-~bis(2-chloro-ethyl~amino~phenyl~butanoyloxy]propyl})carbamoyl~-pyridinium methanosulfate:
The product of Example 84 (2.2 9, n.on47 mol) was dissolved in 45 mL of dry acetonitrile, dimethyl sul-fate (O.S9 g, 0.0047 mol) was added and the mixture was refluxed under argon. The progress of the reaction was followed by thin layer chromatography using 8:2 methy-lene chloride/ethyl acetate. After one and one-half days, the solvent was removed by evaporation in vacuo, leaving an orange residue. The residue was washed thoroughly with anhydrous ether and was dried ~n vacuo. The product, obtained as a yellow sticky mass in 92.47X yield, had the structural formula:

clcH2~2~2h ~ (C2J3 '7 ' EXA~PLE 86 Preparation of 1-Methyl-3-t(N-~2-[4-({4-~bis(2-chloro-ethyl~]amino}phenyl)butanoyloxy]propyl~)carbamoy1]-1,4-dihydropyridine:
The quaternary salt prepared in Example 85 (2.39 9, 0.004 mol) was dissolved in 1 mL of acetonitrile and then taken up in 100 mL of degassed water (bubbling N2) and cooled to 0C in an ice-water bath. Sodium bicarbonate t2.03 9, n.n24 mol) was added to the stirring solution, followed by 2.~1 9 (0.016 mol) of sodium dithionite. To the resultant mixture, 60 mL of ethyl acetate were added. The reaction was allowed to continue for 90 minutes, then the phases were separated and the aqueous phase was extracted 3 or 4 times with 30 mL portions of ethyl acetate. The combined ethyl acetate extracts were dried over sodium sulfate and evaporated ~n vacuo. The residue was applied to a neutral alumina column and eluted with chloroform under pressure. The appropriate fractions were evaporated to give a hygroscopic yellow solid in 60X yield. The product had the formula:

(C 1 CH2CH2 )2t~ ~ CH3 ~3 as confirmed by UV analysis.

EXA~PLE 87 Preparation of N-(2-Hydroxy-2-phenyl)ethyl-3-pyridine-carboxamide:
Nicotinic acid (1.79 g, 0.014 mol) was suspended in 60 mL of dry tetrahydrofuran and 1.48 g (0.014 mol) of freshly distilled triethylamine were added. The clear solution which resulted was cooled to -4C in an ice bath and argon was bubbled through it continuously.
Ethyl chloroformate (1.58 9, 0.014 mol) in 10 mL of tetrahydrofuran was added at such a rate that the temperature did not exceed 0C. Then, 2.0 9 (0.014 mol) of 2-amino-1-phenylethanol were added as a solution in 5 mL of tetrahydrofuran. The reaction mixture was allowed to warm to room temperature and was stirred for 2 hours. The precipitate which formed was removed by filtration and the filtrate was evaporated _ vacuo to give 3.22 g (91.lX) of a white crystalline ZO solid melting at 122-124C and having the formula Elemental analysis confirmed the identity of the product.

EXA~PLE 88 Preparation of N-(~2-Phenyl-2-~4-([4_~bis(2-chloro-ethyl)~amino}phenyl~butanoyloxy]~ethyl)-3-pyridinecar-boxamide:
Chlorambucil (1.0 9, ~.003 mol) and N-(2-hydroxy-2-phenyl~ethyl-3-pyridinecarboxamide (0.88 9, 0.003 mol) were combined with 0.68 9 (0.003 mol) of dicyclo-hexylcarbodiimide and 41 mg (0.0003 mol) of 4-(dimethylamino)pyridine (OMAP) in 35 mL of freshly distilled acetonitrile. The reaction mixture was stirred dt room temperature under argon for 3 days.
Thin layer chromatography using ~:2 methylene chloride/ethyl acetate was used to follow the progress of the reaction. The precipitate which formed was removed by filtration and the acetonitrile was eva-porated in vacuo. The residue thus obtained was applied to a silica column and eluted with 8:2 methylene chloride/ethyl acetate. The appropriate fractions were collected and evaporated in vacuo to give a light tan powder (1.21 9, 70X) melting at 99-101C and having the formula (clcH2cH2)2 ~3(CH2)3~211H~

1 3364~8 EXA~PLE 89 Preparatlon of 1-Methyl-3-t(N-~2-phenyl-2-[4-(~4-~bis (2-chloroethyl~]amino}phenyl)butanoyloxy]~ethyl~carba-moyl]pyridinium methanosulfate:
The product of Example 88 (0.5 9, 0.00094 mol) was dissolved in 20 mL of dry acetonitrile and 0.12 9 (0.00094 mol) of dimethyl sulfate WdS added. The m1xture was refluxed under argon for 2 days, then the solvent was removed by evaporation in vacuo. rhe residue which was obtained was washed several times with anhydrous ether and dried to give 0.54 9 (9lX) of a sticky light yellow product having the formula (C C 2CII~)Z~ !)3~32 ~ C-3504 EXA~PLE 90 Preparation of l-~ethyl-3-[(N-{2-phenyl-2-[4-({4-~bis(2-chloroethyl~amino~phenyl)butanoyloxy]}ethyl~-carbamoyl-1,4-dihydropyridine:
The quaternary salt prepared in Example 89 (0.53 9, 0.0008 mol) was dissolved in 0.5 mL of acetonitrile and taken up ln 20 mL of degassed, deionized water cooled to 0C. Sodium b1carbonate was added to the st1rr1ng solut1On at 0C, followed by 0.56 9 (0.0032 mol~ of sodium dithlonite. Then, 20 mL of ethyl - l88- 1 3 3 6 4 9 8 acetate were added and the reaction was allowed to continue for 2 hours. ~he organic phase was removed and the aqueous phase was extracted several times with ethyl acetate (total volume 70 mL), until color was no longer observed in the organic phase. The ethyl acetate extracts were comblned and dried over sodium sulfate and evaporated in vacuo. The residue was applied to a neutral alumina column and eluted with chloroform. Evaporation of chloroform gave 0.2 9 (45~) of a hygroscopic orangish yellow compound of the formula ( C 1 CH2CH2 ) 2 ~ ( C112 ) 3 0C~HCH2 ~

The identity of the product was confirmed by UV
spectral analysis.

EX~PLE 91 Preparation of ~-(2-Hydroxyethyl~-3-pyridinecarboxa-mide:
A neat mixture of 2-aminoethanol (6.1 9, n.10 mol) and ethyl nicotinate (15.1 9, n.10 mol) was refluxed overnight. As the mixture was cooled to room tempera-ture, the product precipitated as a crystalline solid. It was filtered, washed with ether and then recrystallized from 2-propanol/ether. ~he ftnal product was collected by vacuum filtratton and washed w~th ether. The dried, whlte compound weighed 10.7 9, resu1ting in a 64.5X yield; mp 88.5-89.5C (lit. value 92C).

EXA~PLE 92 Preparation of (+~N-[2-(6-Methoxy-a-methyl-2-naph-thalenylacetoxy)ethyl]-3-pyridinecarboxamide:
Haproxen (2.30 9, 1~.0 mmol) was coupled with the product of Example 91 (1.71 9, 10.0 mmol) using di-cyclohexylcarbodiimide (2.30 9, 11.0 mmol) and 4-(di-methylamino)pyridjne (122 mg, 1.00 mmol) in acetoni-trile (150 mL). The reaction was stirred at room temperature for 48 hours. The precipitate was fil-tered, rinsed with acetonitrile and dried to a weight of 2.3 9. The solvent was ,emoved under reduced pressure and the residual clear oil was stirred with anhydrous ether. The resulting white solid was vacuum filtered, washed with ether and air-dried. The crude product weighed 2.80 9. The compound was recrystal-lized from 2-propanol. The final product was filtered, washed with 0.5X aqueous sodium bicarbonate, water, and finally with ether. The compound was dried in a desiccator over P205. The recrystallized material weighed 2.40 g resulting in an overall yield of 63.4~;
mp 79-82C.

EXA~PLE 93 Preparation of ~-(2-{~1-(p-Chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl~acetoxy~ethyl)-3-pyridinecarboxamide:
A react1On of indomethacin (1.79 9, 5.00 mmol) and the product of Example 91 (0.830 9, 5.00 mmol) was carried out, using dicyclohexylcarbodiimide (1.10 9, - lgo- 1 3 3 6 4 9 8 5.50 mmol) as the coupling agent and acetonitrile as the solvent. The first two reactants were dissolved completely and the solution was then cooled to 0C.
The dicyclohexylcarbodiimide was added and the mixture S was stirred overnight. The reaction was allowed to continue for 48 hours. The precipitate (1.2 9) was removed by vacuum filtration. The solvent was removed from the filtrate under reduced pressure leaving an oily residue. The product was solidified by stirring with anhydrous ether. It was filtered, air-dried and recrystallized from ethanol/ether. The final product was vacuum filtered, washed with ether, and air dried. The product weighed 1.65 9, giving a 65.2X
yield; mp 123-125C.

EXA~PLE 94 Preparation of 1-Methyl-3-{N-[2-(6-methoxy-~-methyl-2-naphthalenylacetoxy)ethyl]cdrbdmoyl~pyridinium iodide:
The quaternization of the naproxen ester prepared in Example 92 (1.0 9, 2.6 mmol) was carried out using methyl iodide (2.3 9, 16 mmol) in acetone (45 mL). The solution was heated to reflux for 20 hours. Methyl iodide (1.1 9, 8.0 mmol) was again added to the reaction flask. The precipitated product was filtered after an additional 4 hours of reaction time. The off-white powder was dried. The material weighed 2.2 9 and was found to be analytically pure without recrystalli-zation. The solvent was removed from the acetone ftltrate and the residue was solidtf~ed with anhydrous ether. The resulting dark yellow powder was dtssolved in water and wdshed with ether (4 x 30 mL). The water was then removed under vacuum giving 0.2 9 of a lighter yellow powder. The overall yield of the reaction was 93~; mp 169-170C. The product had the structural formula CNH ( CH2 ) 20CCH

5 dS further confirmed by UV, NMR and elemental analyses.

EXA~PLE 95 Preparation of l-~ethyl-3-tN-(2-~rl-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl~acetoxy~ethyl~carhamoyl]-pyridinium iodide:
The quaternization of the indomethacin ester pre-pared in Example 93 (0.50 9, 1.0 mmol) was carried out in acetone, using methyl iodide (1.7 9, 12 mmol). The reaction was refluxed overnight. The solvent was re-moved under reduced pressure and a yellow solid was obtained. The product was recrystallized using ethanol and a very small amount of ether. Small mold-like crystals were obtained which were light yellow in color. The reaction gave 0.43 9 or a 66~ yield of the purified material; mp 178-179C. UV, NMR and elemental analyses confirmed that the product had the structural formula:

o o 13cO ~;~H2C ( CH2 )2 C=O 3 EXA~PLE 96 Preparation of 1-Methyl-3-~N-[Z-(6-methoxy-a-methyl-2-naphthalenylacetoxy)ethyl]carbamoyl~-1,4-dihydro-pyridine:
The quaternary salt prepared in Example 94 ~780 mg, 1.5 mmol) was dissolved in degassed, deionized water (200 mL) and acetonitrile (10 mL). Sodium dithionite (780 mg, 4.5 mmol) and sodium bicarbonate (630 mg, 7.5 mmol) were combined and added to the solution at room temperature. The reaction was continued for 1 hour, while nitrogen gas was slowly bubbled through the solution. The partially pre-cipitated product was extracted repeatedly with ether (8 x 30 mL). The extracts were combined, washed with water (25 mL) and dried over magnesium sulfate. The drying agent was fi1tered and the solvent was removed from the filtrate under reduced pressure. The oily residue was dissolved in methylene chloride (3 x 5 mL~
and removed under reduced pressure. The resulting foam was rinsed with anhydrous ether (3 mL) and the solvent was removed under vacuum. The final product weighed 390 mg, giving a 66X yield. The hygroscopic solid foam was stored under nitrogen at -100C. It had the struc-tural formula:

~CNH(CH2)20CC ~OCH3 .

as confirmed by UV, NMR and elemental analyses.

E%A~PLE 97 Preparation of l-~ethyl-3-~N-(2-{[1-(p-chloroben~oyl~-5-methoxy-2-methyl-3-indolyl]acetoxy}ethyl)carbamoyl]
1,4-dihydropyridine:
The indomethacin quaternary salt prepared in Example 95 (140 mg, 0.22 mmol), was dissolved in a minimum amount of water:acetonitrile (8:2). The water had been bubbled with nitrogen for 20 minutes prior to its use. Sodium bicarbonate (91 mg, 1.1 mmol) and sodium dithionite (110 mg, 0.65 mmol) were added to the solution while stirring at 0C. The solution was then allowed to warm to room temperature. The reaction was continued for about 1 hour Some of the product had precipitated during the reaction. This was dissolved in ethyl ether. The water layer was extracted several times with ether until no more yellow color transferred to the organic layer. The ether portions were combined and dried with magnesium sulfate, filtered and the ether was removed under reduced pressure. The result-ing oil was dissolved in acetone and the solvent was removed (2 x 10 mL) under reduced pressure to form a dry foam. The final product weighed 92 mg. rhe yield was 82X; mp 60-65C. The product had the formula:

o o 3 CO _~o ~ CH2l~0 ( CH2 ) 2~1HC~

as confirmed by UV, N~R and elemental analyses.

Preparation of ~-[(l-Hydroxycyclohexyl~methyl]-3-pyridinecarboxamide:
To 1.48 g (0.012 mol) of nicotinic acid suspended in 50 mL of dry tetrahydrofuran, 2.44 9 (0.014 mol) of freshly distilled triethylamine were added, with stirring. The resultant clear solution was cooled to -4C in an ice bath, under argon. Then, 1.3 9 (0.012 mol~ of ethyl chloroformate in 10 mL of tetrahydrofuran were added at such a rate that the temperature of the reaction mixture did not exceed 0C. To the cold reaction mixture, 2.0 9 (0.012 mol) of l-aminomethyl-l-lS cyclohexanol hydrochloride were added directly as a powder. The reaction mixture was allowed to warm to room temperature and stirred for 2 hours, then the triethylamine hydrochloride which formed was removed by filtration and the filtrate was evaporated in vacuo to afford a white solid. The solid was recrystallized from water, washed with acetone and ether and dried.
The title compound, obtained in 85~ yield (2.4 9), melted at around 110C, and was further characterized by the structural formula GH

CH2~

as confirmed by elemental analysis.

EXA~PLE 99 Preparation of ~ 1-t4-(~4-~Bist2-chloroethyl)]amino}-phenyl~butanoyloxy~cyclohexyl~methyl~-3-pyridine-carboxamide:
Chlorambucil (1.18 9, 0.0038 mol~ and ~-[(1-hydroxycyclohexyl)methyl]-3-pyridinecarboxamide (0.99 9, 0.004 mol) were combined with 0.8 9 (0.0038 mol~ of dicyclohexylcarbodiimide and 47 mg (0.00038 mol) of 4-(dimethylamino)pyridine (DMAP) in 60 mL of freshly distilled acetonit,ile. The reaction mixture was stirred at room temperature under argon for 7 days. At the end of that time, the precipitate which formed was separated by filtration and the filtrate was evaporated to dryness at low temperature in vacuo. The residue was applied to a silica column and eluted, first with 8:2 methylene chloride/ethyl acetate, then with 8:Z chloroform/tetrahydrofuran. The appropriate eluting portions were combined and evaporated to dryness in vacuo. The title compound was obtained in 26~ yield as a light yellow solid melting at 92-94C.
It had the structural formula 0-C-(CH2)3 ~ / 2Cz CH2HH~

as confirmed by elemental analysis.

EXA~PLE 100 Preparation of !-~ethyl-3-[N-({1-[4-(4-~[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]cyclohexyl}-methyl~carbamoyl]pyridinium methanosulfate:
To 0.69 g (0.0013 mol) of the product of Example 99, dissolved in 25 mL of dry acetonitrile, was added n.l7 9 (0.0013 mol) of dimethxl sulfate. The mixture was refluxed until the reaction was complete (approxi-mately 2 days), dS evidenced ~y thin layer chromato-graphy using R:~ chloroformttetrahydrofuran. The solvent was removed by evaporation in vacuo to afford an orange residue. which was washed several times with anhydrous ether and dried. The product was obtained as a sticky yellow mass (85~, 0.72 9) ~aving the formula:

O-C-~CH2)3~ CRZCR2C;

CH2NH~C~ CH3S04-EXA~PLE 101 Preparation of 1-Methyl-3-tN-(fl-[4-(4-{[bis(2-chloroethyl~]amino~phenyl)butanoyloxy]cyclohexyl}-methyl)carbamoyl-1,4-dihydropyridine:
The quaternary salt prepared in Example 100 (0.78 9, 0.0012 mol) was dissolved in O.S mL of acetonitrile and taken up in 20 mL of water degassed with bubbling N2, cooled to 0C. To the stirring solution, 0.61 9 (0.0072 mol~ of sodium bicarbonate was added, followed by 0.84 9 (0.0048 mol) of sodium dithionite and 20 mL
of ethyl acetate. The reaction was allowed to proceed for 75 minutes, then the layers were separated and the aqueous layer was extracted 3 to 4 times with 20 mL of ethyl acetate. The organic extracts were combined, dried over sodium sulfate and evaporated in vacuo. The residue was applied to a neutral alumina column and eluted with chloroform under pressure. Evaporation afforded the product as a sticky yellow mass (0.31 9, 49~ having the structural formula:

O-C-(CH2)3~ ~C 2C 2 ~ \CH2CH2Cl CH,NHC~

EXA~PLE 102 Preparation of 1-~ethyl-3-~[2-(9-guanylmethoxy)ethoxy~-carbonyl~pyridinium iodide:
Trigonelline anhydride diiodide (1-methylpyri-dinium-3-carboxylic acid anhydride diiodide) was prepared as described by Brewster et al, Synthetic Co~munications, 17(4~, 451-455 (1987).
To a solution of 1.0 9 (4.4 mmol) of acyclovir in 25 mL of freshly distilled dry pyridine were added 2.27 9 (4.4 mmol) of trigonelline anhydride diiodide and a catalytic amount (5.4 mg, 4 mmol) of 4-(dimethyl-amino)pyridine (DMAP). The resultant suspension was stirred for 4 days under argon at room temperature. As the reaction proceeded, the orange color of the anhydride was replaced with a yellow color. When all of the acyclovir had been consumed, the reaction was stopped, the precipitate (containing the product ester plus the trigonelline formed as a by-product) was removed by filtration and washed with acetone and ether to remove OMAP. The yellow solid was then stirred in dry methanol at room temperature to remove trigonelline, unreacted anhydride and acyclovir. The title compound was obtained in 87X yield (1.82 9), melting at 201-202C. NMR and UV analyses confirmed that the product had the formula:

/~CI~ ,O (CH2)2 OC~) EXA~PLE 103 Preparation of l-Methyl-3-{~2-(9-guanylmethoxy)ethoxy~-carbonyl~-1,4-dihydropyridine:
rO a solution of 1.58 9 (3.3 mmol~ of the product of Example 102 in 120 mL of degassed water were added 1.69 9 (20.1 mmol) of NaHC03 in one portion. The mixture was stirred at 0C while 2.33 9 (13.18 mmol) of sodium dithionite were added over a 5 minute period.
The flask was flushed with nitrogen throughout the reaction process. The dihydropyridine product was insoluble in water and formed cream-colored crystals on top of the water layer. The crystals were separated by filtration and washed, first with ice-cold water and then with anhydrous ether. Drying over P205 in a dessicator maintained at -15C afforded 0.626 9 (54S) of the title compound melting at 163-165C. NMR and UV
analyses confirmed that the product had the formula:

~\~ N ~) 2 ¦ O

(~H 3 Preparation of S'-Pivaloyltrifluorothymidine:
rO a stirring solution of 150 mg of trifluoro-thymidine in 5 mL of pyridine was added a solution of 90 mg of pivaloyl chloride in 1 mL of pyridine. with cooling. Stirring was continued at room temperature for 10 hours, then the reaction mixture was poured into 20 mL of ice water and extracted with 50 mL of ethyl acetate. The extract was washed with water and dried over sodium sulfate. The ethyl acetate was removed and the residue was purified by silica gel column chroma-tography using 20:1 chloroform/methanol as eluent. The title compound melted at 130-132C after recrystalliza-tion from a mixture of ether and n-hexane.

EXA~PLE 105 Preparation of 3'-(3-Pyrtdylcarbonyl)-5'-pivaloyltri-fluorothymidine:
To a stirring solution of 450 mg of 5'-pivaloyl-trifluorothymidine in 10 mL of pyridine was added 1.0 9 of nicotinoyl chloride hydrochloride under ice-cooling. The reaction mixture WdS stirred at room temperature for 3 days, then was poured into 100 mL of ice water and extracted with 100 mL of ethyl acetate.
The extract was washed with water, dried over anhydrous sodium sulfate and then evaporated in vacuo to give an oil. Crystallization from n-hexane afforded 500 mg (87~) of colorless needles melting at 175-177C. The product had the structure ` 1 336498 J~,, CF3 ol N J
( CH3 ) 3C -C -0--C~
~1~
J,c,~

as further confirmed by NMR spectral analysis.

EXA~PLE 106 Preparation of 3'-(1-Methy1-3-pyridiniumcarbonyl)-5'-pivaloyltrifluorothymidine iodide:
To 44n mg of the product of Example 1n5 dissolved in 10 mL of acetone, 1.0 g of methyl iodide was added. The mixture was refluxed for 10 hours, then the precipitate which formed was collected by suction filtration to give 550 mg of the desired product as yellow leaves melting at 188-190C with decomposition.
NMR analysis confirmed that the product had the structural formula:

CH3 ) 3C -C-O--CL~, ~0~
~H3 EXA~PLE 107 Preparation of 3'-(1,4-Dihydro-1-methyl-3-pyridinyl-carbonyl~-5'-pivaloyltrifluorothymidine:
To a stirring solution of 100 mg of the product of Example 106 in a mixture of 20 mL of water and 20 mL of ethyl acetate were added h4 mg of NaHC03 and 115 mg of Na2S204 under N2 gas. The resultant mixture was stirred at room temperature for 1 hour, then the organic layer was separated and washed with water. The extract was dried over anhydrous Na2S04 and evaporated in vacuo. The residue was triturated with a mixture of ether and n-hexane and the yellow needles which formed were collected by suction filtration (50 mg, fi2S). The product melted at 168-170C. NMR analysis confirmed that the product had the structural formula:

HIIJ~ 3 1l o~
(al3)1C--C--O--~H2 \_,/

J ~

EXA~PLE 108 Preparation of 3'-~zido-3'-deoxy-5'-(3-pyridyl-carbonyl)thymidine:
A mlxture of 1.18 9 (4.42 mmol) of azidothymidine~
1.11 9 (4.~6 mmol) of nicotinic anhydride and 0.15 9 (1.22 mmol) of N-(dimethylamino)pyridine was combined in 50 mL of pyridine. The reaction mixture was stirred at room temperature overnight. The clear, colorless reaction mixture was concentrated in vacuo to a semisolid opaque mass which was triturated with ether overnight. The suspension was filtered and dried to give 1.97 9 of solid. Then, 1.0 9 of the solid was chromatographed over 20 9 of silica gel using lOX
ethanol/chloroform as eluent. The desired fraction was isolated as 0.53 9 of a white foam, which was crystal-lized from a solvent mixture of ethanol, diethyl ether and hexane. The product melted at 138.5-141.5C and had the structural formula ~J~ CH3 o CH20C~

as confirmed by NMR and IR.

Preparation of 3'-Azido-3'-deoxy-5'-~(1-methyl-3-pyridinium)carbonyl]thymidine iodide:
A mixture of 0.53 9 (2.0 mmol) of azidothymidine, 1.02 9 (2.2 mmol) of trigonelline anhydride diiodide and 67 mg (0.5 mmol) of N-(dimethylamino)pyridine was combined in 25 mL of pyridine. The reaction mixture was stirred at room temperature for 5 days, then WdS
filtered. The filtrate was concentrated in vacuo to a residue which was triturated with acetone overnight.
The resulting suspension was filtered and the filtrate was concentrated in vacuo to a foam, which was treated with water and ftltered to remove a small amount of insoluble material. The filtrate was concentrated in vacuo to a solld yellow glass (0.50 9, 49t). NMR and UV analysis confirmed that the product had the formula:

J~, CH3 ,!J

~ ~ I -~3 3 EXA~PLE 110Preparation of 3'-Azido-3'-deoxy-5'-~(1-methyl-1,4-dihydro-3-pyridinyl)carbonyl~thymidine:
The crude azidothymidine quaternary derivative prepared according to the procedure of Example 109 (1.45 9, 2.82 mmol) was dissolved in sn mL of water and filtered. The filtrate was cooled in an ice bath and saturated with argon. Then, 100 mL of ethyl acetate and 2.90 9 of NaHC03 were added, followed by 1.45 9 Of Na2S204 after 5 minutes. The reaction was allowed to proceed for 1 hour, then the ethyl acetate layer was removed and fresh ethyl acetate was added. This procedure was repeated to give three organic extracts and a reaction time of 3 hours. The extracts were pooled and concentrated in vacuo to a foam weighing 1.01 9 (925). The foam WdS crystallized from methanol to give the title compound of the formula -206- l 3 3 6 4 9 8 HN ~ CH3 o Jl Hz~
I

~3 melting at 13~-140C. Its structure was confirmed by elemental analysis as well as NMR and UV.

EXA~PLE 11 1 S Preparation of Dopamine dipivalate, oxalate salt:
To a stirred mixture of 28.1 9 of pivaloyl chloride and 150 mL of trifluoroacetic acid, 18.01 9 of dopamine hydrobromide were added. The mixture was stirred for 2 hours, then 14 mL of water were added and the mixture was concentrated in vacuo. The residual oil was dissolved in chloroform and washed with cold 10X KHC03 solution until C02 evolution ceased. The layers were separated and washed with water and the chloroform layer was dried over MgS04, filtered and evaporated to dryness The residue was taken up in 1nn mL of ethyl acetate and 7 9 of oxalic acid were added together with 100 mL of ethyl acetate. rhe resultant solution was f~ltered to remove insoluble materials and 1.6 9 oxalic acid in 25 m~ of ethyl acetate were added. The mixture was concentrated in vacuo and cooled. The crystals which formed were isolated by filtration, giving 13 9 of the title compound. Cooling of the mother liquor afforded a second crop of crystals (5.9 9). The product had the formula:

(CH3)lCCO ,~CH2CH2NH2 . C0OH
J~J COOH
3 ) 3C8 EXAttPLE 112 Preparation of Chloromethyl N-~B-[3,4-bis(pivalyloxy)-phenyl]ethyl~aminocarboxylate:
Dopamine dipivalate, oxalate salt (822 mg, 2 mmol) was suspended in 15 mL of dry tetrahydrofuran. Tri-ethylamine (278 mL, 1 mmol) was added, the mixture was stirred for 15 minutes and a further 278 mL (1 mmol) of triethylamine were then added. Addition of ClC02CH2Cl (390 mg, ~ mmol) resulted in immediate formation of a heavy white precipitate and the evolution of gas. The reaction mixture was stirred overnight at room tempera-ture, then the precipitate was removed by filtration and the filtrate was washed with 10 mL of 0.1 M hydro-chloric acid. Drytng over magnesium sulfate and evaporatton to dryness afforded 1.1 9 of a golden oil of the structural formula o (CH3)3CC0~ 2ul2l~HcocH

( CH3 )3CCO ~J

The identity of the product was confirmed by elemental analysis.

EXA~PLE 11 3 Preparation of N-{~-~3,4-Bis(pivalyloxy)phenyl]ethyl~-aminocarbonyloxymethyl 3-pyridinecarboxylate:
The chloromethyl carbamate prepared in Example 112 (1.26 9, 3.04 mmol) was combined with 10 mL of dry dimethylformamide and that mixture was added to a pre-mixed solution of nicotinic acid (375 mg, 3.04 mmol)and triethylamine (445 mL, 5X excess) in 15 mL of dry dimethylformamide at room temperature. The reaction mixture was stirred for 4 days, then the precipitate which formed was removed by filtration. The filtrate was evaporated to dryness and the residue was taken up in 20 mL of methylene chloride. That solution was washed twice with lO mL portions of water. Removal of the solvent in vacuo afforded the t~tle compound of the formula:

O O O
( CH3 ) 3CCO ~ CH2CH21.HCOI:H~ C

( CH3 ) 3CDCO N

The identity of the product was confirmed by NMR.

EXA~PLE 114 Preparation of ~-{B-~3,4-Bis(pivalyloxy)phenyl]ethyl}-aminocarbonyloxymethyl 1-methyl-3-pyridinium carboxylate iodide:
The product of Example 113 (860 mg, 1.78 mmol) was combined with 15 mL of dry acetonitrile and that mixture was treated with 223 mL (3.56 mmol) of methyl iodide. The resultant mixture was stirred for 6 hours at room temperature, then an additional 223 mL (3.56 mmol~ of methyl iodide was added and the mixture was stirred overnight. Evaporation to dryness afforded, as an orange-red oil, the title compound of the formula ~H3 )3 I~f 1' 11 ~

The identity of the product was confirmed by NMR
analysis.

EXA~PLE 115 Preparation of N-~B-~3,4-Bis(pivalyloxy)phenyl~ethyl~-aminocarbonyloxymethyl 1,4-dihydro-1-methyl-3-pyridine-carboxylate:
The quaternary salt prepared in Example 114 (54 mg, n.o84 mmol) in 10 mL of water was treated at 0C
under nitrogen with NaHC03 (30 mg, 4 equivalents), Ha2S204 (60 mg, 4 equivalents) and ethyl acetate (20 mL). The reaction was allowed to proceed for 1 hour 20 minutes, then the aqueous and organic layers were separated and the aqueous layer was re-extracted with 20 mL of ethyl acetate. The combined organics were dried over magnesium sulfate. Removal of the solvent in vacuo gave a red-orange oil which was taken up in chloroform and partially purified by elution with chloroform from a short neutral alumina column. ~he desired fraction was subjected to preparative thin layer chromatography on silica using 80:20 chloro-form/acetone. The highest band was taken as the title compound of the structural formula:

o o o ( CH3 ) 3CCO ~ CH2cH2ll~rocu2~
Ch3 ) 3C11 Ct~3 o The identity of the product was confirmed by ~PLC (high pressure liquid chromatography) deter0inations for its ability to release dopamine from plasma and brain homogenate.

EXA~PLE 116 Preparation of 9-Fluoro-llB,17-dihydroxy-16~-methyl-21-~(3-pyridinylcarbonyl~oxy]pre9na-l~4-diene-3~2o-dione:
nexamethasone (1 9, 2.5 mmol) was dissolved in 50 mL of dry pyridine. To that solution were added 680 mg (3.0 mmol) of nicotinic anhydride and a trace of 4-(dimethylamino)pyridine (nMAP). The reaction was allowed to proceed for 4 hours, then the reaction mixture was poured over ice water and refrigerated overnight. The solid was collected by filtration and dried to give l.n8 9 (87X) of product melting at 262-265C and having the structural formula O ~N
CH20C~>
H3 ~
HO /~--CH3 H3C _ l 0~

as confirmed by elemental analysis.

EXA~PLE 117 Preparation of l-Methyl-3-~t(9-fluoro-11B,17-dihydroxy-16~-methylpregna-1,4-diene-3,20-dion-21-yl)oxy]-carbonyl}pyridinium iodide:
The product of Example 116 (0.74 9, 1.5 mmol) was dissolved in 50 mL of acetone to which 2 mL of methyl iodide was added. A small amount (10 mL) of CH3N03 was subsequently added to increase solubility. The reaction was allowed to proceed for 2 days, then the solid was collected to give 0.54 9 (56S yield) of the title compound melting at 218-221C and having the formula N~CH3 CH20C~
C=O

HO~-_-CH

I
0~

The structure of the product was confirmed by elemental analysis.

EXA~PLE 118 Preparation of 9-fluoro-113,17-dihydroxy-16Q-methyl-21-~t(l-methyl-1,4-dihydropyridin-3-yl)carbonyl~oxy~-pregna-1,4-diene-3,20-dione:
The general reduction procedure of Example 11 of U.S. Patent No. 4,617,298 was followed, using 0.78 mmol of the steroidal quaternary salt prepared in Example 117, 0.33 9 of ~a~C03 and 0.41 9 of Na2S204 in 50X
aqueous methanol at 0C, with a nitrogen purge. The product had the structural formula:

o /CH3 .'0 HO
H ;C--~OH- -C H 3 0~

EXA~PLE 119 Preparation of 1IB.17-Dihydroxy-21-[(3-pyridinyl-carbonyl)oxy]pregn-4-ene-3,20-dione:
Hydrocortisone (2 9, 5.5 mmol) was dissolved in 50 mL of dry pyridine. Then, 1.38 9 of nicotinoyl anhy-dride (6.05 mmol) and a trace of 4-(dimethylamino)pyri-dine (DMAP) were added and the reaction was allowed to proceed for 4 hours at room temperature. The pyridine solution was poured into ice water and the resulting solid was collected by filtration. The solid was dried over P205 in vacuo to give 2.4 9 (~3%) of the title compound of the formula o r~

~ 20 ~) W~~;OH
3 ¦ . l Og~

as confirmed by elemental analysis and UV spectral analysis.

1 33649%

EXA~PLE 120 Preparation of l-~ethyl-3-~[(11 g,l7-dihydroxypre9n-4 ene-3,20-dion-21-yl)oxy]carbonyl}pyridinium iodide:
The product of Example 119 ( 1 9, 2.1 mmol) was dissolved in S0 mL of acetone and 4 mL of methyl iodide were added. The solution was stirred at the reflux temperature overnight. Removal of the solvent gave the title compound as a yellow powder in 98X yield. Ele-mental analysis confirmed that the product had the formula:

O r~N~ 3 CH20C~) HO~/ OH
H3C ¦ l ~~`f 0~

EXA~PLE 121 Preparation of llB,17-Dihydroxy-21-~ methyl-1,4-dihydropyridin-3-yl)carbonyl~oxy~pregn-4-ene-3,20-lS dione:
The general reduction procedure of Example 11 ofU.S. Patent No. 4,617,298 was followed, using n.~ mmol of the steroidal quaternary salt prepared in Example 120, 0.34 9 of NaHC03 and 0.42 9 of Na2S204 in 50X
aqueous methanol at 0C, with a n~trogen purge. The product had the structural formula:

o ~/ CH3 tH2C ~
I

HO 1~- - OH
H3C l l o,~ ~~

EXA~PLE 122 Preparation of N-(2-Chloroethyl)-H'-~2-(3-pyridine-carbonyloxy)ethyl]-N-nitrosourea:
~ solution of 2-aminoethyl nicotinate dihydro-chloride (1.25 9, 52 mmol) and 2,4,5-trichlorophenyl-N-(2-chloroethyl)-N-nitrosocarbamate (2 9, 6 mmol) in 40 mL of pyridine was stirred under nitrogen at room temperature for 24 hours. The reaction was monitored by thin layer chromatography (silica, 1:1 chloro-form/ethyl acetate, Rf 0.26). The solvent was removed in vacuo and the residue ~as chromatographed on a silica gel column by eluting, first with benzene to remove unreacted nitrosocarbamdte and trichlorophen by-product, and then with chloroform, to give the desired product. The resultant oil solidified in the freezer. rt melted at 63-64C and had the formul d ~ e~ 2CH2NNC:O

EXA~PLE 123 Preparation of N-(2-Chloroethyl~-N'-[2-(1-methyl-3-pyridiniumcarbonyloxy)ethyl]-N-nitrosourea iodide:
A solution of the product of Example 122 (1.5 9, 5 mmol) in 40 mL of tetrahydrofuran was treated with excess methyl iodide. The mixture was stirred at 50C
for 4 hours. The finely crystalline, yellow solid thus obtained (1.8 9, 82X) melted at 12n-121C and had the structure o o -OCH2~H2HHC-~ O

H ~ 2 CH3 ~. I

as confirmed by elemental analysis.

EXA~PLE 12~
Preparation of H-(2-Chloroethyl)-N'-~2-(1.4-dihydro-1-methyl-3-pyridinecarbonyloxy)ethyl]-N-nitrosourea:
A solution of the quaternary nitrosourea prepared in Example 123 (0.48 9, 1.1 mmol) and 1-benzyl-1,2-dihydroisonicotinamide (n.23 9, 1 mmol) in 25 mL of anhydrous methanol was stirred at 0C for 4 hours under nitrogen. The solid which separated was filtered and washed with methanol and ether. The solid was identi-fied as 1-benzyl-4-carbamoylpyridinium iodide by NMR.
The filtrate was evaporated 7n vacuo at about 30C and the residue was suspended in methylene chloride. The solid that separated was filtered and washed with methylene chloride. The filtrate was evaporated in vacuo and the residue was dissolved in chloroform.
Flash chromatography on a short column of neutral alumina, using chloroform as eluent, gave a chloroform solution which was evaporated in vacuo to afford n.2 9 (63~) of a gummy residue, identified by NMR as the desired product of the formula [~ OCH2CH2HHb- ~HCH2CH2C

An alcoholic solution of silver nitrate was readily reduced by the compound thus obtained.

-219- l 3 3 6 4 9 8 EXA~PLE 125 Preparation of N-(2-Fluoroethyl)-N'-[2-(3-pyridine-carbonyloxy)ethyl~-N-nitrosourea:
A solution of 2-aminoethyl nicotinate dihydro-chloride (1.5 9, 6.3 mmol) and 2,4,s-trichlorophenyl-N-(2-fluoroethyl)-N-nitrosocarbamate (2.18 9, 6.9 mmol) in 50 mL of pyridine was stirred under nitrogen at room temperature for 24 hours. The reaction was monitored by thin layer chromatography (silica, 1:1 chloro-form/ethyl acetate, Rf 0.25~. The solvent was removed in vacuo and the residue was chromatographed on a silica gel column by eluting, first with benzene to remove unreacted nitrosocarbamate and trichlorophenol, and then with chloroform to elute the desired product. The compound (1.56 g, 87.4X) melted at 75-77C and was characterized by the structural formula:

U2~;:0 EXA~PLE 126 Preparation of N-(2-Fluoroethyl)-N'-~2-(1-methyl-3-pyrid1niumcarbonyloxy)ethyl]-N-nitrosourea iodide:
A solution of the product of Example 125 (1.56 9, 5.4 mmol) in 40 mL of tetrahydrofuran was treated with excess methyl iodide. The mixture was stirred at 50C
for 4 hours. The finely crystalline. yellow solid thus obtained (2.20 9, 94.1X) melted at 123-125C and had the structural formula ~o ,o, EXA~PLE 127 Preparation of N-(2-Fluoroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)ethyl]-N-nitrosourea:
A solution of the quaternary nitrosourea prepared in Example 12fi (0.426 9, 1 mmol~ and 1-benzyl-1,2-dihydroisonicotinamide (n.21 9, 1 mmol) in 25 mL of anhydrous methanol was stirred at 0C for 4 hours under nitrogen. The solvent was evaporated in vacuo at about 30C and the residue was suspended in chloroform, f11tered and flash chromatographed on a short column of neutral alumina. The title compound was obtained in -2Zl-55S yield after elution with chloroform and was assigned the structure ~ 2 2 ,~ ~ 2 2 consistent with UV analysis.

EXA~PLE lZ8 Preparation of Chloromethyl nicotinate:
To a suspension of nicotinic acid (1.23 9, 0.01 mol) in a mixture of 10 mL of water and 20 mL of tetrahydrofuran were added tetrabutylammonium hydro-gensulfate (0.34 9, 1 mmol) and sodium bicarbonate (3.19 9, n.o38 mol), with vigorous stirring. Chloro-methyl chlorosulfate (1.81 9, 0.011 mol) in 5 mL of tetrahydrofuran was added dropwise, keeping the tem-perature below 30C. The reaction mixture was stirred for I hour, then the layers were separated and the organic layer was dried by azeotroping with 1:1 acetonitrile/benzene. The residue was passed through d column of neutral alumina, eluting with chloroform.
The chloroform layer was evaporated to give 1.28 9 (74.8X) of an oily residue, which was confirmed by NMR
analysis to have the structural for~ula:

~, C~-C~2-Cl EXA~PLE 129 Preparation of l-(Pyridine-3-carbonyloxymethyl~-5-fluorouracil:
5-FU (1.31 9, n.01 mol) was dissolved in 5 mL of dimethylacetamide and treated with triethylamine (2.78 mL, n.o2 mol). Chloromethyl nicotinate (2.95 9, 0.012 mol) in 5 mL of dimethylacetamide was added in one portion, and the mixture was stirred for 24 hours, filtered, washed with ethyl acetate and evaporated.
The residue was chromatographed on a column of silica gel, using as eluent first benzene, then 3:1 ben-zene/chloroform, then 1:1 benzene/chloroform, then 3:1 chloroform/benzene, then chloroform and finally 99:1 chloroform/methanol. Unreacted nicotinate was eluted initially, followed by the 1,3-bis-isomer and finally the l-isomer. The l-isomer (1.3 9, 50X) melted at 190-192~C and had the formula ~ COCH2-N ~

as confirmed by NMR analysis.

EXA~PLE 130 Preparation of 1,3-Bis(pyridine-3-carbonyloxymethyl)-S-fluorouracil:
S-FU (1.31 9, 0.01 mol) was dissolved in S mL of dimethylacetamide and treated with triethy1amine (5.6 mL, 0.04 mol). Chloromethyl nicotinate (6.8 9, 0.04 mol) in lS mL of dimethylacetamide was added in one portion, then the mixture was stirred for 48 hours and filtered, and the filter cake was washed with ethyl acetate. The filtrate was evaporated ~n vacuo and the residue was diluted with 100 mL of water and extracted with chloroform. The organic layer was evaporated and the residue was dried by azeotroping with 1:1 acetonitrile/benzene. The residue was chromatographed on a column of neutral alumina, eluting successively with benzene, 1:1 benzene/chloroform, and SO:SO:I
benzene/chloroform/methanol, to give 3.2 9 (80~) of the bis-isomer of the formula as confirmed by N~R analysis.

EXA~PLE 131 Preparation of 3-(Pyridine-3-carbonyloxymethyl)-S-fluorouracil:
The 1.3-bis-isomer prepared in Example 130 was S dissolved in 10 mL of methanol and mixed with 20 mL of potassium carbonate:sodium bicarbonate buffer (O.lM), pH 10.00. The mixture was stirred at room temperature for 2 hours, by which time thin layer chromatography indicated that the bis-isomer had disappeared completely. The mixture was evaporated and the residue was chromatographed on d column of alumina, eluting successively with chloroform, 99:1 chloroform/methanol and 96:4 chloroform/methanol. The fractions were collected and those containing the 3-isomer were pooled and evaporated to give the compound of the formula [~ COCH~-N ~

as a solid (0.2 9, 30~) melting at 179-18nC. The identity of the product was confirmed by N~R analysis.

EXA~PLE 132 Preparation of l-(l-~ethyl-3-pyridiniumcarbonyloxy-methyl)-S-fluorouracil iodide:
The l-isomer prepared in Example 129 (1.93 9) was combined with sufficient quantities of methyl iodide and acetonitrile, and the mixture was refluxed for 4 hours, then cooled and filtered to give 2.5 9 of a light yellow, fluffy solid. The filtrate was eva-porated, triturated with acetonitrile and filtered to give an additional 0.23 9; total yield 2.73 9 (92.25X). UV and N~R analyses confirmed that the product had the structural formula:

~OCtl2-N ~

EXA~PLE 133 Preparation of 1-(1 ,4-Oihydro-1-methyl-3-pyridinyl-carbonyloxymethyl)-5-fluorouracil:
The product of Example 132 (1 9) WdS dissolved in 20 mL of deionized water (degassed with argon) and cooled in an ice-bath, then 2~ mL of ethyl acetate were added. To the stirred solution, 1.24 9 of sodium bicarbonate were added, followed after about one minute with 1.75 9 of sodium dithionite. The reaction was allowed to proceed under argon and was monitored by UV. After approximately 75 minutes, ethanol waS added and the solid was filtered, washed with water and methylene chloride and dried under argon to give 400 mg of the title compound. UV and N~R analyses confirmed that the product had the structural formula:

' COCH2--N /~/

The aqueous layer was repeatedly extracted with chloro-form and combined with the ethyl acetate layer used in the reaction. rhe solid obtained after removal of the organic solvent was suspended in acetonitrile and filtered to give an additional 250 mg of product melting at 173-174C.

EXA~PLE 134 Preparation of 3-(1-Methyl-3-pyridiniumcarbonyloxy-methyl)-5-fluorouracil iodide:
The 3-isomer prepared in Example 131 can be sub-jected to the general procedure of Example 132 to afford the corresponding quaternary salt of the formula:

-227- l 3 3 6 4 9 8 Preparation of 3-(1,4-~ihydro-l-methyl-3-pyridinyl-carbonyloxymethyl)-5-fluorouracil:
The product of Example 134 can be subjected to the general procedure of ~xample 133 to afford the corres-ponding dihydropyridine of the formula:

o U
~3~ COCH2--N~

The parenteral formulations employed in the method of the present invention can be used to treat a variety of conditions, depending upon the pharmacological nature of the drug selected for administration. In the case of the redox carrier-drugs, the pharmacological nature of the parent drug itself from which the carrier drug is derived will be determinative. Thus, with respect to the carrier-drugs, in one preferred embodiment, the redox system is derived from dopamine or L-DOPA or a protected counterpart thereof, and the redox derivative/cyclodextrin parenteral formulation is thus designed to elicit a sustained and brain-specific dopaminergic (e.g. anti-Parkinsonism or anti-hyperprolactinemia) response in the animal to which the formulation is administered. In analogous fashion, the redox derivative/cyclodextrin parenteral formulation derlved from any other centrally acting drug as defined herein is designed to elicit the kind of pharmaco-logical response which would be obtained by delivery of the drug itself to the brain, i.e. when the centrally acting parent drug is an antitumor/anticancer agent, the instant formulation is employed to elicit an antitumor/anticancer response; when the parent drug is a sympathetic stimulant, the instant formulation is used to elicit a sympathetic stimulant or amphetamine-like response; when the parent drug is an anticonvul-sant compound, the instant formulation is used to elicit an anticonvulsant response; when the parent drug is a tranquilizer, the instant formulation is used to elicit a tranquilizing response; when the parent drug is an antidepressant, the instant formulation is used to elicit an antidepressant response; and so forth.

-229- l 3 3 6 4 9 8 The parenteral formulations used in the method of the present invention contain a pharmacologically effective amount of at least one selected lipophilic and/or water-labile drug in an aqueous solution con-taining from about 20% to about 50% of a hydroxypropyl,hydroxyethyl, glucosyl, maltosyl or maltotriosyl deri-vative of B- or ~-cyclodextrin, preferably of hydroxy-propyl-~-cyclodextrin. These formulations are sterile and pyrogen-free, and are prepared in accord with accepted pharmaceutical procedures, for example as described in Remington's Pharmaceutical Sciences, seventeenth edition, ed. Alfonso R. Gennaro, Mack Publishing Company, Easton, PA (1985), pp. 1518-1552.
The aqueous sterile injection solutions may further contain anti-oxidants, buffers, bacteriostats, iso-tonicity adjusters and like additions acceptable for parenteral formulations. Various unit dose and multi-dose containers, e.g. sealed ampules and vials, may be used, as is well-known in the art. The essential ingredients of the sterile parenteral formulation, i.e.
the drug(s), water and selected cyclodextrin, may be presented in a variety of ways, just so long as the solution ultimately administered to the patient con-tains the appropriate amounts of the essential ingre-dients. Thus, for example, the drug/cyclodextrin/waterformulation may be presented in a unit dose or multi-dose container, ready for injection. As another example, a concentrated solution of drug/cyclodex-trin/water may be presented in a separate container from a diluting liquid (water or cyclodextrin/water) designed so that the contents can be combined to give a formulation containing appropriate amounts for injection. As another alternative, the drug or a drug/cyclodextrin combination may be provided in a freeze-dried condition in one container, while a separate container contains diluting liquid (water or cyclodextrin/water, depending on the amount of cyclo-dextrin in the other container), again designed so that the contents can be combined to give a formulation con-taining the appropriate amounts of the essential ingre-dients. In any event, the contents of each container will be sterile.
Generally speaking, the therapeutic dosage ranges for administration of drugs in the parenteral formula-tions described herein will be the same as or less than (in some instances, substantially less than) those lS characteristically used for administration of the drug per se (or, in the case of the carrier-drugs, of the parent drug species per se). Naturally, such thera-peutic dosage ranges will vary with the size and species of the patient, the condition for which the formulation is administered, the type of parenteral administration employed and the like. The quantity of given dosage form needed to deliver the desired dose of active ingredients will of course depend upon the con-centration of the drug in the parenteral formulation.
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims.

Claims (15)

1. A method for decreasing the tendency of a lipo-philic and/or water-labile drug to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said method comprising formulating said drug in an aqueous solution adapted for parenteral administration con-taining from about 2070 to about 50% of a hydroxypropyl, hydroxyethyl, glucosyl, maltosyl or maltotriosyl deri-vative of .beta.- or .gamma.-cyclodextrin.

2. A method for decreasing the tendency of a lipo-philic and/or water-labile drug to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said method comprising formulating said drug in an aqueous solution adapted for parenteral administration con-taining from about 20%to about 50% of a hydroxypropyl, hydroxyethyl, glucosyl, maltosyl or maltotriosyl deri-vative of .beta.- or .gamma.-cyclodextrin, with the proviso that when the solution contains from about 20% to about 50%
hydroxypropyl-.beta.-cyclodextrin, then said drug is other than the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydropyridine form of a dihy-dropyridine ? pyridinium salt redox system for brain-targeted drug delivery.

3. A method according to Claim 1 or 2, wherein the aqueous solution is approximately isotonic.

4. A method according to Claim 1 or 2, wherein said drug is an antineoplastic.

5. A method according to Claim 1 or 2, wherein said drug is a sedative, tranquilizer, anticonvulsant, anti-depressant, hypnotic, muscle relaxant or antispasmodic.

6. A method according to Claim 1 or 2, wherein said drug is an androgen, estrogen, progestin or anti-inflammatory steroid.

7. A method according to Claim 1 or 2, wherein said drug is a steroidal hypnotic or anesthetic.

8. A method according to Claim 1 or 2, wherein said drug is an anticoagulant, cardiotonic, vasodilator, vasoconstrictor, platelet inhibitor or anti-arrhythmic.

9. A method according to Claim 1 or 2, wherein said drug is an antifungal, antiprotozoal, antibacterial, antibiotic or antiviral.

10. A method according to Claim 1 or 2, wherein said drug is a vitamin/nutritional factor, emetic, anti-emetic, diuretic, non-steroidal anti-inflammatory agent, anesthetic, hypoglycemic, radiodiagnostic, car-bonic anhydrase inhibitor, narcotic antagonist, narcotic agonist, mixed narcotic agonist-antagonist, pharmacologically active protein, dopaminergic/anti-Parkinsonism agent or agent for treating Alzheimer's disease.

11. A method according to Claim 4, wherein said drug is chlorambucil, lomustine, melphalan, methotrexate, hexamethylmelamine, teniposide, etoposide, semustine, fazarabine, mercaptopurine, tubulazole, carmofur, car-mustine, amsacrine, bruceantin, diaziquone, didemnin B, echinomycin or PCNU.

12. A method according to Claim 5, wherein said drug is a barbiturate or a benzodiazepine.

13. A method according to Claim 5, wherein said drug is phenytoin, pentobarbital, phenobarbital, secobarbi-tal, sulpiride, etomidate, chlordiazepoxide, diazepam, medazepam, oxazepam or lorazepam.

14. A method according to Claim 6, wherein said drug is dexamethasone, hydrocortisone, prednisolone, 17.beta.-estradiol, 17.alpha.-ethynylestradiol, ethynylestradiol 3-methyl ether, estriol, norethindrone, norethindrone acetate, norgestrel, ethisterone, medroxyprogesterone acetate, progesterone, 17-methyltestosterone or testos-terone.

15. A method according to Claim 7, wherein said drug is alfaxalone.
15. A method according to Claim 8, wherein said drug is dicumarol, digoxin, digitoxin, nitroglycerin, flunarizine, alprostadil or prostacyclin.
17. A method according to Claim 9, wherein said drug is ampicillin, penicillin G, ketoconazole, itracona-zole, metronidazole benzoate, miconacole, flubendazole or co-trimoxazole.
18. A method according to Claim 10, wherein said drug is retinol, vitamin A-acetate, cholecalciferol, retinal, an E, D or K vitamin, apomorphine, chlorthali-done, furosemide, spironolactone, indomethacin, piroxi-cam, flurbiprofen, acetazolamide, lidocaine, acetohexa-mide, dimenhydrinate, L-DOPA or THA.
19. A method according to Claim 1 or 2, wherein said drug is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydropyridine form of a dihy-dropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
20. A method according to Claim 19, wherein the aqueous solution is approximately isotonic.
21. A method according to Claim 19, wherein said dihydropyridine form is a compound of the formula [D-DHC]
wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal form of a dihydropyri-dine ? pyridinium salt redox carrier.
22. A method according to Claim 21, wherein the centrally acting drug species is a dopaminergic agent, an androgenic agent, an anticonvulsant, an anxiolytic agent, a neurotransmitter, an antibiotic or antibac-terial agent, an antidepressant, an antiviral agent, an anticancer or antitumor agent, an antiinflammatory agent, an estrogen or a progestin.
23. A method according to Claim 22, wherein the centrally acting drug species is dopamine, testos-terone, phenytoin, GABA, valproic acid, tyrosine, methicillin, oxacillin, benzylpenicillin, cloxacillin, dicloxacillin, desipramine, acyclovir, trifluorothymi-dine, zidovudine, hydroxy-CCNU, chlorambucil, trypta-mine, dexamethasone, hydrocortisone, ethinyl estradiol, norethindrone, estradiol, ethisterone, norgestrel, estrone, estradiol 3-methyl ether, estradiol benzoate, norethynodrel, mestranol, indomethacin, naproxen, FENU, HENU or 5-FU.
24. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 1-methyl-3-{{N-{.beta.-[3,4-bis(pivalyloxy)phenyl]ethyl}carbamoyl}}-1,4-dihydropyridine, 1-methyl-3-{N-[[.beta.-[3,4-bis(isobutyryl-oxy)phenyl]ethyl]]}carbamoyl-1,4-dihydropyridine or N-{.beta.-[3,4-bis(pivalyloxy)phenyl]ethyl}aminocarbonyloxy-methyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
25. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 17.beta.-[(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)oxy]androst-4-en-3-one or 17.beta.-{[(3"-carbamoyl-1',4'-dihydropyridinyl)acetyl]oxy}-androst-4-en-3-one.
26. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 5,5-diphenyl-3-[(1'-methyl-1',4'-dihydropyridin-3'-yl)carbonyloxymethyl]-2,4-imidazolidinedione, 3-[3'-carbamoyl-1',4'-dihydropyridin-1'-yl)acetyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione or 3-[3'-(3"-carbamoyl-1",4"-dihydropyridin-1"-yl)propionyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione.
27. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[3-(benzyloxycarbonyl)propyl]carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(3'-cyclohexylcarbonyl)propyl]}-carbamoyl-1,4-dihydropyridine.

28. A method according to Claim 23, wherein the compound of the formula [D-DHC] is l-methyl-3-[2'-(2"-propyl)pentanoyloxy]ethylcarbamoyl-1,4-dihydropyridine, 1-methyl-3-[2'-(2"-propyl)pentanoyloxy]ethoxycarbonyl-1,4-dihydropyridine or 1-[2'-(2"-propyl)pentanoyloxy]-ethyl-3-carboxamide-1,4-dihydropyridine.
29. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 1-methyl-3-{N-[(1'-ethoxycarbonyl)-2'-(4"-pivaloyloxyphenyl)ethyl]}-carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(l'-ethoxycarbonyl)-2'-(4"-isobutyryloxyphenyl)ethyl]}-carbamoyl-1,4-dihydropyridine.
30. A method according to Claim 23, wherein the compound of the formula [D-DHC] is [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-3,3-dimethyl-7-oxo-6-[(2,6-dimethoxy)benzamido]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)-3,3-dimethyl-6-(5-methyl-3-phenyl-4-isoxazolecarboxamido)-7-oxo-4-thia-1-azabicyclo[3.2.0]-heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]-4-thia-1-azabi-cyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2-chlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate or [[(1,4-dihydro-1-methyl-3-pyridinyl)car-bonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2,6-dichloro-phenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate.

31. A method according to Claim 23, wherein the compound of the formula [D-DHC] is [{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}carbonyloxy]methyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate or [1-{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}-carbonyloxy]ethyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
32. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 1-methyl-3-{[2-(9-guanylmethoxy)ethoxy]carbonyl}-1,4-dihydropyridine.
33. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 3'-(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)-5'-pivaloyltrifluoro-thymidine.
34. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 3'-azido-3'-deoxy-5'-(1-methyl-1,4-dihydro-3-pyridinyl)carbonyl]-thymidine.
35. A method according to Claim 23, wherein the compound of the formula [D-DHC] is N-(2-chloroethyl)-N'-[4-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)-cyclohexyl]-N-nitrosourea, N-(2-fluoroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)ethyl]-N-nitrosourea or N-(2-chloroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)ethyl]-N-nitrosourea.
36. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 1-methyl-3-[(N-{2-[4-({4-[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]-ethyl})carbamoyl]-1,4-dihydropyridine, 1-methyl-3-(N-{4-[4-(4-{[bis(2-chloroethyl)]amino}phenyl)-butanoyloxy]cyclohexyl}carbamoyl)-1,4-dihydropyridine, 1-methyl-3-[(N-{2-[4-({4-bis(2-chloroethyl)]amino}-phenyl)butanoyloxy]propyl})carbamoyl]-1,4-dihydropyridine, 1-methyl-3-[(N-{2-phenyl-2-({4-[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]}ethyl)carba-moyl]-1,4-dihydropyridine or 1-methyl-3-[N-({1-[4-(4-{[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]cyclo-hexyl}methyl)carbamoyl]-1,4-dihydropyridine.
37. A method according to Claim 23, wherein the compound of the formula [D-OHC] is 1-methyl-3-N-[2-(3-indolyl)ethyl]carbamoyl-1,4-dihydropyridine.
38. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 9-fluoro-11.beta.,17-dihydroxy-16.alpha.-methyl-21-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregna-1,4-diene-3,20-dione or 11.beta.,17-dihydroxy-21-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregn-4-ene-3,20-dione.
39. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxyestra-1,3,5(10)-triene.
40. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-trien-20-yne, 3-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-17-one, 17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)-carbonyloxy]estra-1,3,5(10)-trien-3-ol 3-methyl ether, 3,17.beta.-bis-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}estra-1,3,5(10)-triene, 3-(phenylcar-bonyloxy)-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}estra-1,3,5(10)-triene or 3-methoxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-triene-20-yne.
41. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-4-en-20-yn-3-one, 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}pregn-4-en-20-yn-3-one, 13-ethyl-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-18,19-dinorpregn-4-en-20-yn-3-one or 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-5(10)-en-20-yn-3-one.
42. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 1-methyl-3-[N-(2-{1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl]-acetoxy}ethyl)carbamoyl]-1,4-dihydropyridine or 1-methyl-3-{N-[2-(6-methoxy-.alpha.-methyl-2-naphthalenyl-acetoxy)ethyl]carbamoyl-1,4-dihydropyridine.
43. A method according to Claim 23, wherein the compound of the formula [D-DHC] is 3-(1,4-dihydro-1-methyl-3-pyridinylcarbonyloxymethyl)-5-fluorouracil or 1-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxymethyl)-5-fluorouracil.
44. A method for decreasing the tendency of a lipo-philic and/or water-labile drug to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said method comprising formulating said drug in an aqueous solution adapted for parenteral administration con-taining from about 20% to about 50% hydroxypropyl-.beta.-cyclodextrin.
45. A method for decreasing the tendency of a lipophilic and/or water-labile drug to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said method comprising formulating said drug in an aqueous solution adapted for parenteral administration con-taining from about 20% to about 50% hydroxypropyl-.beta.-cyclodextrin, with the proviso that said drug is other than the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydropyridine form of a dihydropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
46. A method according to Claim 44 or 45, wherein the aqueous solution is approximately isotonic.
47. A method according to Claim 44 or 45, wherein said drug is an antineoplastic.
48. A method according to Claim 44 or 45, wherein said drug is a sedative, tranquilizer, anticonvulsant, antidepressant, hypnotic, muscle relaxant or antispasmodic.
49. A method according to Claim 44 or 45, wherein said drug is an androgen, estrogen, progestin or anti-inflammatory steroid.
50. A method according to Claim 44 or 45, wherein said drug is a steroidal hypnotic or anesthetic.
51. A method according to Claim 44 or 45, wherein said drug is an anticoagulant, cardiotonic, vasodilator, vasoconstrictor, platelet inhibitor or anti-arrhythmic.
52. A method according to Claim 44 or 45, wherein said drug is an antifungal, antiprotozoal, anti-bacterial, antibiotic or antiviral.
53. A method according to Claim 44 or 45, wherein said drug is a vitamin/nutritional factor, emetic, antiemetic, diuretic, non-steroidal anti-inflammatory agent, anesthetic, hypoglycemic, radiodiagnostic, car-bonic anhydrase inhibitor, narcotic antagonist, narcotic agonist, mixed narcotic agonist-antagonist, pharmacologically active protein, dopaminergic/anti-Parkinsonism agent or agent for treating Alzheimer's disease.
54. A method according to Claim 47, wherein said drug is chlorambucil, lomustine, melphalan, methotrexate, hexamethylmelamine, teniposide, etoposide, semustine, fazarabine, mercaptopurine, tubulazole, carmofur, carmustine, amsacrine, bruceantin, diaziquone, didemnin B, echinomycin or PCNU.
55. A method according to Claim 48, wherein said drug is a barbiturate or a benzodiazepine.
56. A method according to Claim 48, wherein said drug is phenytoin, pentobarbital, phenobarbital, secobarbital, sulpiride, etomidate, chlordiazepoxide, diazepam, medazepam, oxazepam or lorazepam.
57. A method according to Claim 49, wherein said drug is dexamethasone, hydrocortisone, prednisolone, 17.beta.-estradiol, 17.alpha.-ethynylestradiol, ethynylestradiol 3-methyl ether, estriol, norethindrone, norethindrone acetate, norgestrel, ethisterone, medroxyprogesterone acetate, progesterone, 17-methyltestosterone or testos-terone.
58. A method according to Claim 50, wherein said drug is alfaxalone.
59. A method according to Claim 51, wherein said drug is dicumarol, digoxin, digitoxin, nitroglycerin, flunarizine, alprostadil or prostacyclin.
60. A method according to Claim 52, wherein said drug is ampicillin, penicillin G, ketoconazole, itraconazole, metronidazole benzoate, miconacole, flubendazole or co-trimoxazole.
61. A method according to Claim 53, wherein said drug is retinol, vitamin A-acetate, cholecalciferol, retinal, an E, D or K vitamin, apomorphine, chlorthali-done, furosemide, spironolactone, indomethacin, piroxi-cam, flurbiprofen, acetazolamide, lidocaine, acetohexa-mide, dimenhydrinate, L-DOPA or THA.
62. A method according to Claim 44, wherein said drug is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydropyridine form of a dihy-dropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
63. A method according to Claim 62, wherein the aqueous solution is approximately isotonic.
64. A method according to Claim 62, wherein said dihydropyridine form is a compound of the formula [D-DHC]
wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal form of a dihydropyri-dine ? pyridinium salt redox carrier.
65. A method according to Claim 64, wherein the centrally acting drug species is a dopaminergic agent, an androgenic agent, an anticonvulsant, an anxiolytic agent, a neurotransmitter, an antibiotic or antibac-terial agent, an antidepressant, an antiviral agent, an anticancer or antitumor agent, an antiinflammatory agent, an estrogen or a progestin.
66. A method according to Claim 65, wherein the centrally acting drug species is dopamine, testos-terone, phenytoin, GABA, valproic acid, tyrosine, methicillin, oxacillin, benzylpenicillin, cloxacillin, dicloxacillin, desipramine, acyclovir, trifluorothymi-dine, zidovudine, hydroxy-CCNU, chlorambucil, trypta-mine, dexamethasone, hydrocortisone, ethinyl estradiol, norethindrone, estradiol, ethisterone, norgestrel, estrone, estradiol 3-methyl ether, estradiol benzoate, norethynodrel, mestranol, indomethacin, naproxen, FENU, HENU or 5-FU.
67. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 1-methyl-3-{{N-{.beta.-[3,4-bis(pivalyloxy)phenyl]ethyl}carbamoyl}}-1,4-dihydropyridine, 1-methyl-3-{N-[[.beta.-[3,4-bis(isobutyryl-oxy)phenyl]ethyl]]}carbamoyl-1,4-dihydropyridine or N-{.beta.-[3,4-bis(pivalyloxy)phenyl]ethyl}aminocarbonyloxy-methyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
68. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 17.beta.-[(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)oxy]androst-4-en-3-one or 17.beta.-{[(3"-carbamoyl-1',4'-dihydropyridinyl)acetyl]oxy}-androst-4-en-3-one.
69. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 5,5-diphenyl-3-[(1'-methyl-1',4'-dihydropyridin-3'-yl)carbonyloxymethyl]-2,4-imidazolidinedione, 3-[3'-carbamoyl -1',4'-dihydropyridin-1'-yl)acetyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione or 3-[3'-(3"-carbamoyl-1",4"-dihydropyridin-1"-yl)propionyloxymethyl ]-5,5-diphenyl-2,4-imidazolidinedione.
70. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[3-(benzyloxycarbonyl)propyl]carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(3'-cyclohexylcarbonyl)propyl]}-carbamoyl-1,4-dihydropyridine.
71. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 1-methyl-3-[2'-(2"-propyl)pentanoyloxy]ethylcarbamoyl-1,4-dihydropyridine, l-methyl-3-[2'-(2"-propyl)pentanoyloxy]ethoxycarbonyl-1,4-dihydropyridine or 1-[2'-(2"-propyl)pentanoyloxy]-ethyl-3-carboxamide-1,4-dihydropyridine.
72. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 1-methyl-3-{N-[(1'-ethoxycarbonyl)-2'-(4"-pivaloyloxyphenyl)ethyl]}-carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(1'-ethoxycarbonyl)-2'-(4"-isobutyryloxyphenyl)ethyl]}-carbamoyl-1,4-dihydropyridine.
73. A method according to Claim 66, wherein the compound of the formula [D-DHC] is [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha. ,5.alpha. ,6.beta.)]-3,3-dimethyl-7-oxo-6-[(2,6-dimethoxy)benzamido]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-l-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)-3,3-dimethyl-6-(5-methyl-3-phenyl-4-isoxazolecarboxamido)-7-oxo-4-thia-1-azabicyclo[3.2.0]-heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]-4-thia-1-azabi-cyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2-chlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate or [[(1,4-dihydro-1-methyl-3-pyridinyl)car-bonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2,6-dichloro-phenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate.
74. A method according to Claim 66, wherein the compound of the formula [D-DHC] is [{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}carbonyloxy]methyl l,4-dihydro-1-methyl-3-pyridinecarboxylate or [l-{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}-carbonyloxy]ethyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
75. A method according to Claim 66, wherein the compound of the formula [D-DHC] is l-methyl-3-{[2-(9-guanylmethoxy)ethoxy]carbonyl}-1,4-dihydropyridine.
76. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 3'-(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)-5'-pivaloyltrifluoro-thymidine.

77. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 3'-azido-3'-deoxy-5'-(1-methyl-1,4-dihydro-3-pyridinyl)carbonyl]-thymidine.
78. A method according to Claim 66, wherein the compound of the formula [D-DHC] is N-(2-chloroethyl)-N'-[4-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)-cyclohexyl]-N-nitrosourea, N-(2-fluoroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)ethyl]-N-nitrosourea or N-(2-chloroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)ethyl]-N-nitrosourea.
79. A method according to Claim 66, wherein the compound of the formula [D-DHC] is l-methyl-3-[(N-{2-[4-({4-[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]-ethyl})carbamoyl]-1,4-dihydropyridine, 1-methyl-3-(N-{4-[4-(4-{[bis(2-chloroethyl)]amino}phenyl)-butanoyloxy]cyclohexyl}carbamoyl)-1,4-dihydropyridine, 1-methyl-3-[(N-{2-[4-({4-bis(2-chloroethyl)]amino}-phenyl)butanoyloxy]propyl})carbamoyl]-1,4-dihydropyridine, 1-methyl-3-[(N-{2-phenyl-2-({4-[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]}ethyl)carba-moyl]-1,4-dihydropyridine or 1-methyl-3-[N-({1-[4-(4-{[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]cyclo-hexyl}methyl)carbamoyl]-1,4-dihydropyridine.
80. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[2-(3-indolyl)ethyl]carbamoyl-1,4-dihydropyridine.
81. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 9-fluoro-11.beta.,17-dihydroxy-16.alpha.-methyl-21-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregna-1,4-diene-3,20-dione or 11.beta.,17-dihydroxy-21-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregn-4-ene-3,20-dione.
82. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxyestra-1,3,5(10)-triene.
83. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-trien-20-yne, 3-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-17-one, 17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)-carbonyloxy]estra-1,3,5(10)-trien-3-ol 3-methyl ether, 3,17.beta.-bis-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}estra-1,3,5(10)-triene, 3-(phenylcar-bonyloxy)-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}estra-1,3,5(10)-triene or 3-methoxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-triene-20-yne.
84. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-4-en-20-yn-3-one, 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}pregn-4-en-20-yn-3-one, 13-ethyl-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-18,19-dinorpregn-4-en-20-yn-3-one or 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-5(10)-en-20-yn-3-one.
85. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 1-methyl-3-[N-(2-{1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl]-acetoxy}ethyl)carbamoyl]-1,4-dihydropyridine or 1-methyl-3-{N-[2-(5-methoxy-.alpha.-methyl-2-naphthalenyl-acetoxy)ethyl]carbamoyl -1,4-dihydropyridine.
86. A method according to Claim 66, wherein the compound of the formula [D-DHC] is 3-(1,4-dihydro-1-methyl-3-pyridinylcarbonyloxymethyl)-5-fluorouracil or 1-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxymethyl)-5-fluorouracil .
87. An improved parenteral drug formulation having decreased tendency to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said formulation comprising a lipophilic and/or water-labile drug in an aqueous solution containing from about 20% to about 50%
of a hydroxypropyl, hydroxyethyl, glucosyl, maltosyl or maltotriosyl derivative of .beta.- or .gamma.-cyclodextrin.
88. An improved parenteral drug formulation having decreased tendency to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said formulation comprising a lipophilic and/or water-labile drug in an aqueous solution containing from about 20% to about 50%
of a hydroxypropyl, hydroxyethyl, glucosyl, maltosyl or maltotriosyl derivative of .beta.- or .gamma.-cyclodextrin, with the proviso that when the solution contains from about 20% to about 50% hydroxypropyl-.beta.-cyclodextrin, then said drug is other than the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydro-pyridine form of a dihydropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
89. A parenteral drug formulation according to Claim 87 or 88, wherein the aqueous solution is approximately isotonic.
90. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is an antineoplastic.
91. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is a sedative, tran-quilizer, anticonvulsant, antidepressant, hypnotic, muscle relaxant or antispasmodic.
92. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is an androgen, estrogen, progestin or anti-inflammatory steroid.
93. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is a steroidal hypnotic or anesthetic.
94. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is an anticoagulant, cardiotonic, vasodilator, vasoconstrictor, platelet inhibitor or anti-arrhythmic.
95. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is an antifungal, anti-protozoal, antibacterial, antibiotic or antiviral.
96. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is a vitamin/nutritional factor, emetic, antiemetic, diuretic, non-steroidal anti-inflammatory agent, anesthetic, hypoglycemic, radiodiagnostic, carbonic anhydrase inhibitor, narcotic antagonist, narcotic agonist, mixed narcotic agonist-antagonist, pharmacologically active protein, dopaminergic/anti-Parkinsonism agent or agent for treating Alzheimer's disease.
97. A parenteral drug formulation according to Claim 90, wherein said drug is chlorambucil, lomustine, melphalan, methotrexate, hexamethylmelamine, teniposide, etoposide, semustine, fazarabine, mercaptopurine, tubulazole, carmofur, carmustine, amsacrine, bruceantin, diaziquone, didemnin B, echinomycin or PCNU.
98. A parenteral drug formulation according to Claim 91, wherein said drug is a barbiturate or a benzo-diazepine.
99. A parenteral drug formulation according to Claim 91, wherein said drug is phenytoin, pentobarbital, phenobarbital, secobarbital, sulpiride, etomidate, chlordiazepoxide, diazepam, medazepam, oxazepam or lorazepam.
100. A parenteral drug formulation according to Claim 92, wherein said drug is dexamethasone, hydrocortisone, prednisolone, 17.beta.-estradiol, 17.alpha.-ethynylestradiol, ethynylestradiol 3-methyl ether, estriol, norethindrone, norethindrone acetate, norgestrel, ethisterone, medroxyprogesterone acetate, progesterone, 17-methyltestosterone or testosterone.
101. A parenteral drug formulation according to Claim 93, wherein said drug is alfaxalone.
102. A parenteral drug formulation according to Claim 94, wherein said drug is dicumarol, digoxin, digitoxin, nitroglycerin, flunarizine, alprostadil or prosta-cyclin.
103. A parenteral drug formulation according to Claim 95, wherein said drug is ampicillin, penicillin G, ketoconazole, itraconazole, metronidazole benzoate, miconacole, flubendazole or co-trimoxazole.
104. A parenteral drug formulation according to Claim 96, wherein said drug is retinol, vitamin A-acetate, cholecalciferol, retinal, an E, D or K vitamin, apomorphine, chlorthalidone, furosemide, spirono-lactone, indomethacin, piroxicam, flurbiprofen, acetazolamide, lidocaine, acetohexamide, dimenhy-drinate, L-DOPA or THA.
105. A parenteral drug formulation according to Claim 87 or 88, wherein said drug is the reduced, biooxi-dizable, blood-brain barrier penetrating, lipoidal dihydropyridine form of a dihydropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
106. A parenteral drug formulation according to Claim 105, wherein the aqueous solution is approximately isotonic.
107. A parenteral drug formulation according to Claim 105, wherein said dihydropyridine form is a compound of the formula [D-DHC]
wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal form of a dihydropyri-dine ? pyridinium salt redox carrier.

108. A parenteral drug formulation according to Claim 107, wherein the centrally acting drug species is a dopaminergic agent, an androgenic agent, an anti-convulsant, an anxiolytic agent, a neurotransmitter, an antibiotic or antibacterial agent, an antidepressant, an antiviral agent, an anticancer or antitumor agent, an antiinflammatory agent, an estrogen or a progestin.
109. A parenteral drug formulation according to Claim 108, wherein the centrally acting drug species is dopamine, testosterone, phenytoin, GABA, valproic acid, tyrosine, methicillin, oxacillin, benzylpenicillin, cloxacillin, dicloxacillin, desipramine, acyclovir, trifluorothymidine, zidovudine, hydroxy-CCNU, chlorambucil, tryptamine, dexamethasone, hydrocortisone, ethinyl estradiol, norethindrone, estradiol, ethisterone, norgestrel, estrone, estradiol 3-methyl ether, estradiol benzoate, norethynodrel, mestranol, indomethacin, naproxen, FENU, HENU or 5-FU.
110. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-{{N-{.beta.-[3,4-bis(pivalyloxy)phenyl]ethyl}-carbamoyl}}-1,4-dihydropyridine, 1-methyl-3-{N-[[.beta.-[3,4-bis(isobutyryloxy)phenyl]ethyl]]}carbamoyl-1,4-dihydropyridine or N-{.beta.-[3,4-bis(pivalyloxy)phenyl]-ethyl}aminocarbonyloxymethyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
111. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 17.beta.-[(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)oxy]-androst-4-en-3-one or 17.beta.-{[(3"-carbamoyl-1',4'-dihydropyridinyl)acetyl]oxy}androst-4-en-3-one.

112. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 5,5-diphenyl-3-[(1'-methyl -1',4'-dihydropyridin-3'-yl)carbonyloxymethyl]-2,4-imidazolidinedione, 3-[3'-carbamoyl-1',4'-dihydropyridin-1'-yl)acetyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione or 3-[3'-(3"-carbamoyl-1",4"-dihydropyridin-1"-yl)propionyloxy-methyl]-5,5-diphenyl-2,4-imidazolidinedione.
113. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[3-(benzyloxycarbonyl)propyl]carbamoyl -1,4-dihydropyridine or l-methyl-3-{N-[(3'-cyclohexyl -carbonyl)propyl]}carbamoyl-1,4-dihydropyridine.
114. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-[2'-(2"-propyl)pentanoyloxy]ethylcarbamoyl-1,4-dihydropyridine, 1-methyl-3-[2'-(2"-propyl)-pentanoyloxy]ethoxycarbonyl -1,4-dihydropyridine or 1-[2'-(2"-propyl)pentanoyloxy]ethyl-3-carboxamide-1,4-dihydropyridine.
115. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl -3-{N-[(1'-ethoxycarbonyl)-2'-(4"-pivaloyloxy-phenyl)ethyl]}carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(1'-ethoxycarbonyl)-2'-(4"-isobutyryl-oxyphenyl)ethyl]}carbamoyl-1,4-dihydropyridine.
116. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is [[(1,4-dihydro-1-methyl -3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-3,3-dimethyl -7-oxo-6-[(2,6-dimethoxy)benzamido]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)-carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)-3,3-dimethyl-6-(5-methyl-3-phenyl-4-isoxazolecarboxamido)-7-oxo-4-thia-1-azabicyclo[3.2.0]-heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,5.beta.)]-3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2-chlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate or [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2,5-dichlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate.
117. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is [{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}carbonyloxy]methyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate or [1-{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}carbonyloxy]ethyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
118. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-{[2-(9-guanylmethoxy)ethoxy]carbonyl}-1,4-dihydropyridine.
119. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 3'-(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)-5'-pivaloyltrifluorothymidine.

120. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 3'-azido-3'-deoxy-5'-(1-methyl-1,4-dihydro-3-pyridinyl)-carbonyl]thymidine.
121. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is N-(2-chloroethyl)-N'-[4-(1,4-dihydro-1-methyl-3-pyridine-carbonyloxy)cyclohexyl]-N-nitrosourea, N-(2-fluoro-ethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridine-carbonyloxy)ethyl]-N-nitrosourea or N-(2-chloroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)-ethyl]-N-nitrosourea.
122. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-[(N-{2-[4-({4-[bis(2-chloroethyl)]amino}-phenyl)butanoyloxy]ethyl})carbamoyl]-1,4-dihydropyri-dine, 1-methyl-3-(N-{4-[4-(4-{[bis(2-chloroethyl)]-amino}phenyl)butanoyloxy]cyclohexyl}carbamoyl)-1,4-dihydropyridine, 1-methyl-3-[(N-{2-[4-({4-bis(2-chloroethyl)]amino}phenyl)butanoyloxy]propyl})carba-moyl]-1,4-dihydropyridine, 1-methyl-3-[(N-{2-phenyl-2-({4-[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]}-ethyl)carbamoyl]-1,4-dihydropyridine or 1-methyl-3-[N-({1-[4-(4-{[bis(2-chloroethyl)]amino}phenyl)-butanoyloxy]cyclohexyl}methyl)carbamoyl]-1,4-dihydropyridine.
123. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[2-(3-indolyl)ethyl]carbamoyl-1,4-dihydro-pyridine.

124. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 9-fluoro-11.beta.,17-dihydroxy-16.alpha.-methyl-21-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregna-1,4-diene-3,20-dione or 11.beta.,17-dihydroxy-21-{[(1-methyl-1,4-dihy-dropyridin-3-yl)carbonyl]oxy}pregn-4-ene-3,20-dione.
125. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-[(1-methyl-1,4-dihydropyridin-3-yl)car-bonyl]oxyestra-1,3,5(10)-triene.
126. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)car-bonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-trien-20-yne, 3-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-17-one, 17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-3-ol 3-methyl ether, 3,17.beta.-bis-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}estra-1,3,5(10)-triene, 3-(phenylcar-bonyloxy)-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}estra-1,3,5(10)-triene or 3-methoxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-triene-20-yne.
127. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-4-en-20-yn-3-one, 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregn-4-en-20-yn-3-one, 13-ethyl-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-18,19-dinorpregn-4-en-20-yn-3-one or 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-5(10)-en-20-yn-3-one.
128. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 1-methyl-3-[N-(2-{1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl]acetoxy}ethyl)carbamoyl]-1,4-dihydropyridine or 1-methyl-3-{N-[2-(6-methoxy-.alpha.-methyl-2-naphthalenyl-acetoxy)ethyl]carbamoyl-1,4-dihydropyridine.
129. A parenteral drug formulation according to Claim 109, wherein the compound of the formula [D-DHC] is 3-(1,4-dihydro-1-methyl-3-pyridinylcarbonyloxymethyl)-5-fluorouracil or 1-(1,4-dihydro-1-methyl-3-pyridine-carbonyloxymethyl)-5-fluorouracil.
130. An improved parenteral drug formulation having decreased tendency to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said formulation comprising a lipophilic and/or water-labile drug in an aqueous solution containing from about 20% to about 50%
hydroxypropyl-.beta.-cyclodextrin.
131. An improved parenteral drug formulation having decreased tendency to collect in the lungs or other organs due to precipitation at or near the injection site and/or in the lungs or other organs themselves following parenteral administration, said formulation comprising a lipophilic and/or water-labile drug in an aqueous solution containing from about 20% to about 50%
hydroxypropyl-.beta.-cyclodextrin, with the proviso that said drug is other than the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydro-pyridine form of a dihydropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
132. A parenteral drug formulation according to Claim 130 or 131, wherein the aqueous solution is approxi-mately isotonic.
133. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is an antineoplastic.
134. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is a sedative, tran-quilizer, anticonvulsant, antidepressant, hypnotic, muscle relaxant or antispasmodic.
135. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is an androgen, estrogen, progestin or anti-inflammatory steroid.
136. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is a steroidal hypnotic or anesthetic.
137. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is an anticoagulant, cardiotonic, vasodilator, vasoconstrictor, platelet inhibitor or anti-arrhythmic.
138. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is an antifungal, anti-protozoal, antibacterial, antibiotic or antiviral.
139. A parenteral drug formulation according to Claim 130 or 131, wherein said drug is a vitamin/nutritional factor, emetic, antiemetic, diuretic, non-steroidal anti-inflammatory agent, anesthetic, hypoglycemic, radiodiagnostic, carbonic anhydrase inhibitor, narcotic antagonist, narcotic agonist, mixed narcotic agonist-antagonist, pharmacologically active protein, dopaminergic/anti-Parkinsonism agent or agent for treating Alzheimer's disease.
140. A parenteral drug formulation according to Claim 133, wherein said drug is chlorambucil, lomustine, melphalan, methotrexate, hexamethylmelamine, teniposide, etoposide, semustine, fazarabine, mercaptopurine, tubulazole, carmofur, carmustine, amsacrine, bruceantin, diaziquone, didemnin B, echinomycin or PCNU.
141. A parenteral drug formulation according to Claim 134, wherein said drug is a barbiturate or a benzo-diazepine.
142. A parenteral drug formulation according to Claim 134, wherein said drug is phenytoin, pentobarbital, phenobarbital, secobarbital, sulpiride, etomidate, chlordiazepoxide, diazepam, medazepam, oxazepam or lorazepam.
143. A parenteral drug formulation according to Claim 135, wherein said drug is dexamethasone, hydrocorti-sone, prednisolone, 17.beta.-estradiol, 17.alpha.-ethynyl-estradiol, ethynylestradiol 3-methyl ether, estriol, norethindrone, norethindrone acetate, norgestrel, ethisterone, medroxyprogesterone acetate, progesterone, 17-methyltestosterone or testosterone.
144. A parenteral drug formulation according to Claim 136, wherein said drug is alfaxalone.
145. A parenteral drug formulation according to Claim 137, wherein said drug is dicumarol, digoxin, digi-toxin, nitroglycerin, flunarizine, alprostadil or prostacyclin.
146. A parenteral drug formulation according to Claim 138, wherein said drug is ampicillin, penicillin G, ketoconazole, itraconazole, metronidazole benzoate, miconacole, flubendazole or co-trimoxazole.
147. A parenteral drug formulation according to Claim 139, wherein said drug is retinol, vitamin A-acetate, cholecalciferol, retinal, an E, D or K vitamin, apomorphine, chlorthalidone, furosemide, spirono-lactone, indomethacin, piroxicam, flurbiprofen, acetazolamide, lidocaine, acetohexamide, dimenhy-drinate, L-DOPA or THA.
148. A parenteral drug formulation according to Claim 130, wherein said drug is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal dihydro-pyridine form of a dihydropyridine ? pyridinium salt redox system for brain-targeted drug delivery.
149. A parenteral drug formulation according to Claim 148, wherein the aqueous solution is approximately isotonic.
150. A parenteral drug formulation according to Claim 148, wherein said dihydropyridine form is a compound of the formula [D-DHC]
wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating, lipoidal form of a dihydropyri-dine ? pyridinium salt redox carrier.

151. A parenteral drug formulation according to Claim 150, wherein the centrally acting drug species is a dopaminergic agent, an androgenic agent, an anti-convulsant, an anxiolytic agent, a neurotransmitter, an antibiotic or antibacterial agent, an antidepressant, an antiviral agent, an anticancer or antitumor agent, an antiinflammatory agent, an estrogen or a progestin.
152. A parenteral drug formulation according to Claim 151, wherein the centrally acting drug species is dopamine, testosterone, phenytoin, GABA, valproic acid, tyrosine, methicillin, oxacillin, benzylpenicillin, cloxacillin, dicloxacillin, desipramine, acyclovir, trifluorothymidine, zidovudine, hydroxy-CCNU, chlorambucil, tryptamine, dexamethasone, hydro-cortisone, ethinyl estradiol, norethindrone, estradiol, ethisterone, norgestrel, estrone, estradiol 3-methyl ether, estradiol benzoate, norethynodrel, mestranol, indomethacin, naproxen, FENU, HENU or 5-FU.
153. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-{{N-{.beta.-[3,4-bis(pivalyloxy)phenyl]ethyl}-carbamoyl}}-1,4-dihydropyridine, 1-methyl-3-{N-[[.beta.-[3,4-bis(isobutyryloxy)phenyl]ethyl]]}carbamoyl-1,4-dihydropyridine or N-{.beta.-[3,4-bis(pivalyloxy)phenyl]-ethyl}aminocarbonyloxymethyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
154. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 17.beta.-[(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)oxy]-androst-4-en-3-one or 17.beta.-{[(3"-carbamoyl-1',4'-dihydropyridinyl)acetyl]oxy}androst-4-en-3-one.

155. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 5,5-diphenyl-3-[(1'-methyl-1',4'-dihydropyridin-3'-yl)carbonyloxymethyl]-2,4-imidazolidinedione, 3-[3'-carbamoyl-1',4'-dihydropyridin-1'-yl)acetyloxymethyl]-5,5-diphenyl-2,4-imidazolidinedione or 3-[3'-(3"-carbamoyl-1",4"-dihydropyridin-1"-yl)propionyloxy-methyl]-5,5-diphenyl-2,4-imidazolidinedione.
156. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[3-(benzyloxycarbonyl)propyl]carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(3'-cyclohexyl-carbonyl)propyl]}carbamoyl-1,4-dihydropyridine.
157. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-[2'-(2"-propyl)pentanoyloxy]ethylcarbamoyl-1,4-dihydropyridine, 1-methyl-3-[2'-(2"-propyl)-pentanoyloxy]ethoxycarbonyl-1,4-dihydropyridine or 1-[2'-(2"-propyl)pentanoyloxy]ethyl-3-carboxamide-1,4-dihydropyridine.
158. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-{N-[(1'-ethoxycarbonyl)-2'-(4"-pivaloyloxy-phenyl)ethyl]}carbamoyl-1,4-dihydropyridine or 1-methyl-3-{N-[(1'-ethoxycarbonyl)-2'-(4"-isobutyryl-oxyphenyl)ethyl]}carbamoyl-1,4-dihydropyridine.
159. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-3,3-dimethyl-7-oxo-6-[(2,6-dimethoxy)benzamido]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)-carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)-3,3-dimethyl-6-(5-methyl-3-phenyl-4-isoxazolecarboxamido)-7-oxo-4-thia-1-azabicyclo[3.2.0]-heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate, [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2-chlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate or [[(1,4-dihydro-1-methyl-3-pyridinyl)carbonyl]oxy]methyl [2S-(2.alpha.,5.alpha.,6.beta.)]-6-[3-(2,6-dichlorophenyl)-5-methyl-4-isoxazolecarboxamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate.
160. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is [{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}carbonyloxy]methyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate or [1-{N-[3-(10,11-dihydro-5H-dibenz[b,f]azepin-5-yl)]propyl-N-methylamino}carbonyloxy]ethyl 1,4-dihydro-1-methyl-3-pyridinecarboxylate.
161. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-{[2-(9-guanylmethoxy)ethoxy]carbonyl}-1,4-dihydropyridine.
162. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 3'-(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)-5'-pivaloyltrifluorothymidine.

163. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 3'-azido-3'-deoxy-5'-(1-methyl-1,4-dihydro-3-pyridinyl)-carbonyl]thymidine.
164. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is N-(2-chloroethyl)-N'-[4-(1,4-dihydro-1-methyl-3-pyridine-carbonyloxy)cyclohexyl]-N-nitrosourea, N-(2-fluoro-ethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridine-carbonyloxy)ethyl]-N-nitrosourea or N-(2-chloroethyl)-N'-[2-(1,4-dihydro-1-methyl-3-pyridinecarbonyloxy)-ethyl]-N-nitrosourea.
165. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-[(N-{2-[4-({4-[bis(2-chloroethyl)]amino}-phenyl)butanoyloxy]ethyl})carbamoyl]-1,4-dihydropyri-dine, 1-methyl-3-(N-{4-[4-(4-{[bis(2-chloroethyl)]-amino}phenyl)butanoyloxy]cyclohexyl}carbamoyl)-1,4-dihydropyridine, 1-methyl-3-[(N-{2-[4-({4-bis(2-chloroethyl)]amino}phenyl)butanoyloxy]propyl})carba-moyl]-1,4-dihydropyridine, 1-methyl-3-[(N-{2-phenyl-2-({4-[bis(2-chloroethyl)]amino}phenyl)butanoyloxy]}-ethyl)carbamoyl]-1,4-dihydropyridine or 1-methyl-3-[N-({1-[4-(4-{[bis(2-chloroethyl)]amino}phenyl)-butanoyloxy]cyclohexyl}methyl)carbamoyl]-1,4-dihydropyridine.
166. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-N-[2-(3-indolyl)ethyl]carbamoyl-1,4-dihydro-pyridine.

167. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 9-fluoro-11.beta.,17-dihydroxy-16a-methyl-21-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregna-1,4-diene-3,20-dione or 11.beta.,17-dihydroxy-21-{[(1-methyl-1,4-dihy-dropyridin-3-yl)carbonyl]oxy}pregn-4-ene-3,20-dione.
168. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-[(1-methyl-1,4-dihydropyridin-3-yl)car-bonyl]oxyestra-1,3,5(10)-triene.
169. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 3-hydroxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)car-bonyl]oxy}-19-nor-17a-pregna-1,3,5(10)-trien-20-yne, 3-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-17-one, 17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-3-ol 3-methyl ether, 3,17.beta.-bis-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}estra-1,3,5(10)-triene, 3-(phenylcar-bonyloxy)-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)-carbonyl]oxy}estra-1,3,5(10)-triene or 3-methoxy-17.beta.-{[1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-nor-17.alpha.-pregna-1,3,5(10)-triene-20-yne.
170. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 17.beta.-i[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-4-en-20-yn-3-one, 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}pregn-4-en-20-yn-3-one, 13-ethyl-17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-18,19-dinorpregn-4-en-20-yn-3-one or 17.beta.-{[(1-methyl-1,4-dihydropyridin-3-yl)carbonyl]oxy}-19-norpregn-5(10)-en-20-yn-3-one.
171. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 1-methyl-3-[N-(2-{1-(p-chlorobenzoyl)-5-methoxy-2-methyl-3-indolyl]acetoxy}ethyl)carbamoyl]-1,4-dihydropyridine or l-methyl-3-{N-[2-(6-methoxy-.alpha.-methyl-2-naphthalenyl-acetoxy)ethyl]carbamoyl-1,4-dihydropyridine.
172. A parenteral drug formulation according to Claim 152, wherein the compound of the formula [D-DHC] is 3-(1,4-dihydro-1-methyl-3-pyridinylcarbonyloxymethyl)-5-fluorouracil or 1-(1,4-dihydro-1-methyl-3-pyridine-carbonyloxymethyl)-5-fluorouracil.