WO2009026133A2

WO2009026133A2 - Transdermal bisoprolol delivery system

Info

Publication number: WO2009026133A2
Application number: PCT/US2008/073270
Authority: WO
Inventors: Jianye Wen; Sangita Ghosh; Delphine Imbert; Tyler D. Westcott
Original assignee: Alza Corporation
Priority date: 2007-08-17
Filing date: 2008-08-15
Publication date: 2009-02-26
Also published as: WO2009026133A3

Abstract

A transdermal bisoprolol delivery system to an individual in need thereof. The system includes a backing layer, a reservoir disposed proximally relative to the backing layer. The reservoir has a polymeric composition containing an amount of bisoprolol or a pharmaceutically acceptable salt thereof sufficient for multiple-day delivery. The system can have a rate-control layer to control the rate of bisoprolol delivery to the user.

Description

TRANSDERMAL BISOPROLOL DELIVERY SYSTEM

TECHNICAL FIELD

[0001] This invention relates to a medical patch for transdermal administration of bisoprolol and to a method of treating a subject by administering bisoprolol thereto with a medical patch. More particularly, the invention relates to transdermal systems for administration of bisoprolol with an adhesive system.

BACKGROUND

[0002] Transdermal devices for the delivery of biologically active agents have been used for maintaining health and treating a wide variety of ailments therapeutically. For example, analgesics, steroids, etc., have been delivered with such devices. Such transdermal devices include patches in which a biologically active agent is delivered to the body tissue passively without use of an additional energy source. Many such devices have been described, for example, in U.S. Pat. Nos. 3,598,122, 3,598,123, 4,379,454, 4,286,592, 4,314,557, 4,568,343, and U.S. Application No. 2003002682, all of which are incorporated herein by reference.

[0003] A patch for transdermal drug delivery is typically a small adhesive bandage that contains the drug to be delivered. A simple type of such transdermal patches is an adhesive monolith including a drug-containing reservoir disposed on a backing. The reservoir is typically formed from a pharmaceutically acceptable pressure sensitive adhesive, which can provide adhesion to the body surface. In some cases, the reservoir can be formed from a non-adhesive material, the body-contacting surface of which is provided with a thin layer of a suitable adhesive, which can also contain the drug being delivered. The rate at which the drug is administered to the patient from these patches can vary due to normal person-to-person and skin site-to-skin site variations in the permeability of skin or body surface to the drug.

[0004] Some patches can be multilaminate and can include a drug release-rate- control membrane disposed between a drug reservoir and the body-contacting adhesive. This membrane, by decreasing the in vitro release rate of drug from the patch, is used to reduce the effect of variations in skin permeability. [0005] Although the transdermal delivery of therapeutic agents has been the subject of intense research and development for over 30 years, only a relatively small number of drugs are suitable for transdermal delivery due to the fact that human skin is an excellent barrier. Various techniques have been explored to enhance the permeation of drugs that are not otherwise suitable for transdermal delivery. Of these techniques, chemical enhancement is the most established and is currently employed commercially. Pressure sensitive adhesives, such as acrylic adhesives, are used in most transdermal drug delivery devices as a means of providing intimate contact between the drug delivery device and the skin. The use of enhancers, especially at high concentrations, usually has a significant impact on the properties of pressure sensitive adhesives, such as cohesive strength, adhesive flow, tackiness and adhesion strength. Further, if a patch is to be used for multiple days, the amount of drugs and enhancers that need to be included in the patch may make the device unacceptably large or thick.

[0006] In the treatment of ailments that are related to the adrenergic nervous system, beta-blockers have been used or proposed to be used in treating symptoms of illnesses such as hypertension or heart related ailments such as angina pectoris, ventricular premature beats. See, for example, patent publications US4460562, US4482533, US5593686; US5719197; US5965155; US20060078604; US20020004065; US20030118652; US20030091633; and US20060240086, which are incorporated by reference in their entireties herein.

[0007] Bisoprolol, which is known as l-[4-[2-(l-methylethoxy)ethoxymethyl] phenoxy]-3-(l-methylethylamino)propan-2-ol, is a beta-1 selective beta blocker with no intrinsic sympathomimetic activity (ISA). The following is a representation of the structure of bisoprolol.

[0008] Bisoprolol has a formula of C₁₈H₃₁NO₄ with a molecular weight of

325.45. Commonly seen bisoprolol salts are fumarate (or called hemifumarate), hydrochloride, and methanesufonate. For example, bisoprolol fumarate has the empirical formula of (Ci8H3iNO4)2 • C4H4O4 with a molecular weight of 766.97 (or 383.48 for each bisoprolol free base mole equivalent). There is an asymmetric carbon in the molecule and racemic mixture contains the L(+) enantiomer and the S(-) enantiomer. The S(-) enantiomer is believed to be responsible for most of the beta- blocking activity. At the present, name brand and generic oral tablets of bisoprolol are commercially available. Bisoprolol has been shown to be an effective prophylactic against migraine in doses of either 5mg or lOmg given once a day. See LLM Van de ven et al. Cephalagia, 1997, 17:596-9. Bisoprolol can also be used to treat cardiovascular diseases such as hypertension, coronary heart disease, arrhythmia, as well as treatment of myocardial infarction after the acute event. Bisoprolol and its salts such as the above-mentioned are effective for treating hypertension. For treating hypertension, doses of from 2.5mg, 5mg, lOmg, and even to 25mg bisoprolol per day have been prescribed. For example, tablets of the bisoprolol fumarate drug ZEBETA can be administered orally with daily doses of 5mg or lOmg to control hypertension. See http://www.fda.gOv/cder/foi/nda/pre96/l 9982-S3_Zebeta.pdf for the Approval Letter for ZEBETA. For treatment of chronic angina pectoris, bisoprolol fumarate is given 5-20mg orally once daily. For treating hypertension, doses of 2.5mg, 5mg, lOmg, and even to 25mg bisoprolol fumarate per day have been prescribed. For treatment of chronic angina pectoris, bisoprolol fumarate is given 5-20mg orally once daily. For treating congestive heart failure, bisoprolol fumarate is given initially at 1.25mg orally once daily and then titrated to higher dose if needed, to a maximum dose of lOmg once daily. Thus, daily doses of 5 to 20mg would be adequate for such treatments. [0009] Oral administration of bisoprolol is, however, sometimes undesirable.

The present oral dosage forms, not being a sustained release dosage form, may lead to large fluctuations in plasma drug levels. Sometimes a patient may have difficulty swallowing pills, or remembering to take the oral doses at all. Patient compliance has been a concern for treatments such as hypertension. Since hypertension does not cause symptoms that the patients can feel, patients sometimes may become lax in taking medication as prescribed. It has been reported that patients initially prescribed antihypertensive medication requiring once-daily or once-weekly administration experienced an increased utilization of antihypertensive medication, needed fewer changes in their therapeutic regimen, and needed far less concomitant therapy for blood pressure control compared with those prescribed a BID regimen. Patients in the once- daily or once-weekly groups also used significantly fewer physician, hospital, and laboratory services (see Skaer, T. L., et al, Clin Ther. 1993 Jul-Aug;15(4):715-25). Thus, it is desirable to have transdermal bisoprolol delivery patches that can continually deliver bisoprolol over an extended period of time. Preparations for skin administration have also been proposed, see WO2007029781. However, some have reported that delivering bisoprolol transdermally at an adequate rate may be difficult and that enhancers will be needed to improve diffusion across human skin. See, Modamio, P.; Lastra, C. F.; Marino, E. L., "Transdermal absorption of celiprolol and bisoprolol in human skin in vitro" International Journal of Pharmaceutics (1998), 173(1,2), 141-148.

[00010] For delivery to humans, better designs to improve bisoprolol permeation will be required. Thus, a transdermal bisoprolol delivery device with adequate drug loading and sufficient flux is needed for effective therapy of ailments such as hypertension or prophylaxis of migraine. There is a need for improved delivery of bisoprolol, especially sustained transdermal delivery over a period of time.

SUMMARY

[00011] This invention provides transdermal bisoprolol delivery devices and formulations that deliver bisoprolol base or a salt thereof at a therapeutically effective level. Since transdermal delivery of bisoprolol has higher bioavailability than oral delivery and the free base form of bisoprolol weighs only about 85% that of the fumarate form per mole, transdermal doses of 2mg, 4mg, 8mg, and even 20mg bisoprolol free base equivalent per day (adjusted for free base form and oral bioavailability) should produce the therapeutic effect like those of the orally delivered bisoprolol as already established in medical practice for the oral route. The formulations have low irritation potential and contain sufficient drug to support one-day or multi-day delivery while maintaining reasonable adhesiveness.

[00012] In one aspect, a transdermal bisoprolol delivery system is provided to provide health benefit to an individual in need of such. The system includes a backing layer, a reservoir containing bisoprolol drug disposed proximally relative to the backing layer for one day or multiple day use. The reservoir has a polymeric composition containing an amount of bisoprolol or a pharmaceutically acceptable salt thereof sufficient for at least one-day delivery, preferably multiple-day delivery. Preferably, there is a rate-control adhesive disposed proximally to the body surface (e.g., skin) relative to the reservoir. The rate-control adhesive disposed proximally relative to the reservoir to control the rate of bisoprolol delivery to the user. Preferably the bisoprolol drug is bisoprolol free base.

[00013] In another aspect, a method of making such a transdermal bisoprolol delivery system and a method of using such a transdermal bisoprolol delivery system are provided. The method for making a transdermal patch for administering a bisoprolol to a user includes disposing a reservoir proximally relative to a backing layer. The reservoir has a polymeric composition that contains an amount of bisoprolol or a pharmaceutically acceptable salt thereof sufficient for at least one-day delivery, preferably multiple-day delivery. Preferably, there is a rate-control adhesive disposed proximally to the body surface relative to the reservoir. The rate-control adhesive is disposed proximally relative to the reservoir to control the rate of bisoprolol delivery to the user. Preferably the bisoprolol drug is bisoprolol free base.

[00014] A transdermal delivery device is provided with a high enough bisoprolol content, preferably completely dissolved into a drug reservoir matrix. Once applied on an individual's body surface, the device can stay adhesively to the body surface over an extended period of time during which bisoprolol is to be delivered by the device, whether the period is 1 day, 3 days or 7 days. The transdermal delivery of bisoprolol may result in lower adverse events than what is seen with oral delivery. Further, a transdermal patch will allow a more steady sustained delivery than doses taken orally at time intervals hours apart. Since the patch will only need to be changed infrequently, it will lead to improved compliance in the patients. This invention allows for the transdermal delivery of a therapeutic dose of bisoprolol (about 2mg to 20mg per day, preferably about 4mg to 8mg per day free base equivalent) from a thin, flexible, user- friendly patch about 20 to 125cm² in size. The therapeutic dose requirement for transdermal administration has been determined by adjusting the prescribed oral dose of bisoprolol fumarate with the oral bioavailability and the molecular weight difference of the salt to that of the free base (which oral bioavailability and molecular weight difference are known to those skilled in the art).

[00015] In an aspect, certain patches are provided that can deliver bisoprolol base systemically at a therapeutically effective rate for providing therapeutic benefits for ailments without using a significant amount of, and even without any, permeation enhancer. In fact, in some cases, rate-control is provided to slow down the flux by including a rate-control in-line adhesive and/or rate-control tie layer(s).

[00016] Such patches can be applied on the body surface of a patient for use to render therapeutic benefits for ailments such as hypertension, migraine, and cardiac disorders such as heart failure, coronary heart disease, and arrhythmia. As used herein, "treatment" or "therapeutic benefit" includes relief or reduction of symptoms and prophylaxis of symptoms. Further, it has been found that perioperative administration of beta-blockers was associated with a reduced risk of death in hospitals among high- risk patients undergoing major noncardiac surgery, such as vascular, orthopedic, abdominal, thoracic surgeries (see Lindenauer, Peter, et al., New England Journal Med. 2005 JuI 28;353(4):349-61). Thus, bisoprolol transdermal delivery systems of the present invention can be used for perioperative administration such as for prophylaxis to reduce the risk of death for surgery in hospitals.

[00017] In another aspect, a method is provided to load enough bisoprolol into the drug reservoir of the transdermal patch that can be worn for an extensive period of time, such as 3 days, or even 7 days. Patches that can be used for such extensive periods of time would increase patient compliance and would reduce a caregiver's burden.

[00018] In one aspect, the present transdermal device with bisoprolol will address some of the challenges to providing optimal bisoprolol therapy. A 3 -day or 7-day transdermal delivery system, in addition to reducing caregiver burden and improving dosing compliance, should result in less gastrointestinal exposure compared to oral administration and could decrease the incidence of gastrointestinal side effects associated with peripheral cholinergic stimulation. Transdermal flux rates which produce gradually increasing plasma levels over several days may reduce the need for dosing titration and simplify the dosing regimen. An ability to achieve and tolerate higher bisoprolol levels or more rapid dose titration would be expected to result in greater efficacy, earlier onset of symptomatic improvement (for symptomatic ailments), or both.

BRIEF DESCRIPTION OF THE DRAWINGS

[00019] The present invention is illustrated by way of example in embodiments and not limitation in the figures of the accompanying drawings in which like references indicate similar elements. The figures are not drawn to scale unless indicated otherwise in the content.

[00020] FIG. 1 illustrates a sectional view of one embodiment of a transdermal therapeutic system according to the present invention.

[00021] FIG. 2 illustrates a sectional view of another embodiment of a transdermal therapeutic system of this invention.

[00022] FIG. 3 illustrates a sectional view of another embodiment of a transdermal therapeutic system of this invention.

[00023] FIG. 4 illustrates an isometric view of a barrier frame of the embodiment shown in FIG. 3 according to this invention. [00024] FIG. 5 illustrates a sectional view of one embodiment of a transdermal therapeutic system according to the present invention.

[00025] FIG. 6 illustrates a sectional view of one embodiment of a transdermal therapeutic system according to the present invention.

[00026] FIG. 7 is a graphical presentation of the flux of bisoprolol for a gel on skin system and for a gel with adhesive on skin system.

[00027] FIG. 8 is a graphical presentation of the flux of bisoprolol for an EVA reservoir on different in-line adhesives.

[00028] FIG. 9 shows a plot of primary irritation indices in hairless guinea pig vs. in vitro skin flux for certain formulations according to this invention.

[00029] FIG. 10 shows a graph of flux of bisoprolol in different embodiments of rate-control according to this invention.

DETAILED DESCRIPTION

[00030] The present invention relates to transdermal delivery of bisoprolol or a salt thereof, especially the uncharged base form of bisoprolol, with or without the help of permeation enhancers to achieve adequate flux of bisoprolol for one ore more days. In one aspect, the present invention relates especially to bisoprolol that is delivered with the use of a body-contacting adhesive that is different from the reservoir carrier that holds the bisoprolol. The body-contacting adhesive maintains the transdermal delivery system on a body surface of an individual.

[00031] In describing the present invention, the following terms will be employed, and are defined as indicated below. As used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural references unless the content clearly dictates otherwise. [00032] As used herein, the term "transdermal" refers to the use of skin, mucosa, and/or other body surfaces as a portal for the administration of drugs by topical application of the drug thereto for passage into the systemic circulation.

[00033] "Biologically active agent" is to be construed in its broadest sense to mean any material that is intended to produce some biological, beneficial, therapeutic, or other intended effect, such as enhancing permeation or relief of hypertension. As used herein, the term "drug" or "therapeutic agent" refers to any material that is intended to produce some biological, beneficial, therapeutic, or other intended effect, such as relief of pain, but not agents (such as permeation enhancers) the primary effect of which is to aid in the delivery of another biologically active agent such as the therapeutic agent transdermally.

[00034] As used herein, the term "matrix" refers to a solid, or semi-solid substance, such as, for example, a polymeric material, adhesive or gel, that has capacity to hold a beneficial agent or drug for transdermal drug delivery. In some cases the matrix can also hold liquid. The matrix serves as a repository (or carrier) in which the beneficial agent or drug is carried (contained) and may be porous. For the sake of convenience, when mentioned along with ingredients, sometimes "matrix" as referred herein can include drugs or ingredients held therein.

[00035] As used herein, the term "therapeutically effective" refers to the amount of drug or the rate of drug administration needed to produce the desired therapeutic result.

[00036] As used herein, all rates or amounts of delivery of bisoprolol are meant to be bisoprolol base equivalent, unless specified otherwise in content.

[00037] As used herein, the term "in-line" when referring to a layer means the layer is in the direct shortest path of the drug flowing from the drug reservoir to the body surface. Thus an in-line adhesive of a device is an adhesive layer that is disposed in the direct shortest path between the drug reservoir and the body surface on which the device is placed such that the drug has to pass through the in-line adhesive to reach the body surface.

[00038] As used herein, "proximal" as related to the direction of positioning a layer relative to another layer refers to a position that is nearer to the body surface relative to another layer when the device is applied thereto, "distal" as related to the direction of positioning a layer relative to another layer refers to a position that is farther from the body surface relative to the another layer when the device is applied thereto, unless specified to be otherwise.

[00039] As used herein, "rate-control" or "rate-controlling" as related to a layer of material in the transdermal system refers to a material that is separate from and adjacent to the drug reservoir and decreases the release rate of the drug from the reservoir. As a result, a rate-controlling layer in-line with the drug reservoir can control or limit the rate of release of the drug from the reservoir and the flux into the body.

[00040] The present invention has utility in connection with the delivery of bisoprolol or salts thereof to an individual in need of the bisoprolol treatment through body surfaces and membranes, including skin. Acids that are used to make pharmaceutically acceptable salts of bisoprolol include but are not limited to hydrochloric acid, hydrobromic acid, acetic acid, fumaric acid, maleic acid, malonic acid, valeric acid, tartaric acid, malonic acid, glycolic acid, citric acid, hexanoic acid, methyl sulfonic acid, and p-toluene sulphonic acid. Bases that are used to make pharmaceutically acceptable salts of bisoprolol include but are not limited to sodium hydroxide, potassium hydroxide, ethanolamine, diethanolamine, triethanolamine, TRIS, pyrrolidine, piperidine, piperizine, morpholine, N-(2-hydroxyethyl) pyrrolidine, N-(2- hydroxyethyl) piperizine, and N-(2-hydroxyethyl) piperidine. Examples of salts of bisoprolol include, but are not limited to hydrochloride, fumarate, tosylate, mesylate, acetate, citrate, tartarate, maleate, sufonate, and glycolate. It is noted that one or more bisoprolol salts can be incorporated into the device with or in place of the bisoprolol base. However, the preferred mode is delivering bisoprolol base. [00041] A suitable transdermal delivery patch according to the present invention is about 5-125cm² in area, and preferably about 10 to 80cm² in area, especially about 10cm² to 40cm² in area. For effective therapy, for example, the delivery of about 2mg to 20mg of bisoprolol free base equivalent daily, preferably about 4mg to 12mg daily, preferably about 4mg to 8mg daily, can be used. A transdermal bisoprolol flux in a range of about 4 to 40mcg/(cm²hr), preferably about 8 to 16mcg/(cm²hr) for a system area of about 20cm² is applicable. For a 40cm² patch, a flux of about 4 to 8mcg/(cm²hr) is applicable.

[00042] The amount of bisoprolol (free base or salt) dissolved in the drug reservoir matrix (on a solid, or dry, basis) can be about 15wt% to 45wt%, preferably about 20wt% to 40wt%, preferably above 25wt%, more preferably from about 25wt% to 40wt%, even more preferably about 25wt% to 35wt%. The balance of the material in the reservoir can be the carrier material. Optionally, other excipients can be included. Such bisoprolol contents are, for example, suitable for patches of about 10 to 40cm² with thickness of about lmil (0.025mm) to 12mil (0.3mm) and having a dose of about 2.5mg to lOmg. Such bisoprolol contents are suitable for effecting flux of therapeutic effect for ailments such as hypertension, migraine, heart failure, etc., with a flux (in microgram (meg or μg) per unit area time) of, e.g., greater than lmcg/(cm²hr), preferably greater than about 2mcg/(cm²hr), more preferably about 3mcg/(cm²hr) to 80mcg/(cm²hr), more preferably about 4mcg/(cm²hr) to 50mcg/(cm²hr), more preferably about 4mcg/(cm²hr) to 25mcg/(cm²hr) for a 1 -day patch or multiple-day patch (e.g., a 3-day patch, 7-day patch). For a patch for one-day use, the concentration and size can be on the lower end of the ranges, e.g., the bisoprolol content can be about 10 to 20wt%, a size of about 5 to 20cm² with thickness of about lmil (0.024mm) to 4mil (0.1mm). Conversely, for a three or more day patch, the drug content and size can be in the larger end of the ranges, e.g., the bisoprolol content can be about 20 to 45wt%, a size of about 10 to 40cm² with thickness of about lmil (0.024mm) to 12mil (0.1mm), although a size of 20cm² or less with thickness 4mil or less can also be used.

[00043] Certain exemplary transdermal drug delivery systems of the present invention are illustrated by the embodiments shown in FIGS. 1 and 2. As shown in FIGS. 1 and 2, an embodiment of the transdermal patch 1 according to this invention has a backing layer 2, a drug reservoir 3 located on the skin (body surface) side of the backing layer 2, a body-contacting adhesive 6 on the body side of the drug reservoir 3, and a peelable protective layer (or release liner) 5 further on the body side of the body- contacting adhesive 6. Upon use, the protective layer or release liner 5 is removed and the device is applied such that the body-contacting adhesive 6 is applied to contact the body surface (e.g., skin). The body-contacting adhesive 6 adheres securely to the body surface. The body-contacting adhesive 6 can also contain the drug and permeation enhancer, as well as other ingredients. The reservoir is a matrix of carrier material that is suitable for carrying the pharmaceutical agent (or drug) bisoprolol for transdermal delivery. Preferably, the whole matrix, with drugs and other optional ingredients, is a material that has the desired adhesive properties. The polymer that makes up the matrix in the reservoir provides the structure for carrying the drug (and other excipients that optionally may be present). However, even if the reservoir matrix does not have adequate adhesive property to adhere directly to the body surface, the body-contacting adhesive will have adhesive property to retain the drug delivery device on the body surface (e.g., skin) for the period desired, whether one day, three days, or seven days. Although the drug and other ingredients carried in the matrix can be above saturation in a multiple phase polymeric composition, preferably at least the drug, and preferably all the other ingredients carried by the matrix in the reservoir 3 are in a single phase polymeric composition in that no drug is undissolved. Preferably all other components are present at concentrations no greater than, and preferably less than, their saturation concentrations in the reservoir 3, without undissolved material. Preferably, it is a composition in which all components are dissolved. The reservoir 3 can be formed using a pharmaceutically acceptable polymeric material that can be an acceptable adhesive for application to the body surface. Preferably the body-contacting adhesive 6 provides good adhesive property to ensure that the device stays attached to the body surface over the desired period. In a multiple phase polymeric composition, at least one component, for example, a therapeutic drug, is present in amount more than the saturation concentration and some of the drug may be in undissolved form, e.g., crystals or particulates. In some embodiments, more than one component, e.g., a drug and a permeation enhancer, is present in amounts above saturation concentration. In the embodiment shown in FIG. 1, the adhesive 3 acts as the reservoir and includes a drug, such as bisoprolol.

[00044] In the embodiment shown in FIG. 2 of a transdermal patch 1, the body- facing surface of the reservoir 3 may be formulated with a thin adhesive coating 6. The reservoir 3 may be a single phase polymeric composition or a multiple phase polymeric composition as described earlier, except that the reservoir matrix may not adhere very well with the skin-contacting adhesive 6. In the embodiment of FIG. 2, a tie layer 8 is disposed between the body-contacting adhesive 6 and the reservoir 3 to bind them tightly together so that they will not be delaminated or separated inadvertently.

[00045] With the use of an overlay adhesive, for example, like that shown in FIG.

3 (discussed below), a skin-contacting adhesive may not be needed. Further, in certain cases, a rate-control layer (not shown) can also be positioned on the reservoir layer proximal to the skin. Any suitable rate-control material described below or known in the art can be used.

[00046] The reservoir 3 may be formed from drug (or biological active agent) reservoir materials suitable for delivery of bisoprolol or its salts. For example, the drug reservoir is formed from a polymeric material in which the drug can be included, preferably all in dissolved form, for the drug to be delivered within the desired range, such as, a polyurethane, ethylene/vinyl acetate copolymer (EVA), polyacrylate, styrenic block copolymer, gel polymer, and the like. Although it may be possible to blend different matrix polymers, it is preferred that one matrix polymer be the main one (i.e., more than 50wt%, preferably more than about 90wt%, and preferably substantially all, and even more preferably all of the matrix carrier material) in the matrix polymeric material. In preferred embodiments, the reservoir 3 is formed from a pharmaceutically acceptable EVA. The drug reservoir or the matrix layer can have a thickness of about l-20mils, about 1-lOmils (0.025- 0.25mm), preferably about 2mils to 5mils (0.05mm to 0.12mm), more preferably about 2mils to 3mils (0.05mm to 0.075mm).

[00047] FIG. 5 and FIG. 6 shows illustrations of embodiments in which no in-line body-contacting adhesive is used. The device 1 has a reservoir 3 positioned between protective liner 5 and backing 2. In the case of FIG. 5, the reservoir material 3 is a monolithic polymeric adhesive layer that contains the drug and also provides adhesion for attaching to the body surface such that the device consists of only the three layers. In the case of FIG. 6, an overlay 14 is positioned on top (at a position most distal from the body surface) of the device 1. The overlay 16 has an adhesive on its body surface facing side to attach to the body surface.

[00048] In certain cases, a rate-controlling layer (not shown in FIG. 5 and FIG. 6) can also be positioned adjacent or next to the reservoir layer proximal to the skin. Any suitable rate-controlling material described herein or known in the art can be used.

[00049] EVA copolymer is a preferred material for making the matrix carrier for carrying bisoprolol or its salts and optionally other ingredients in the reservoir. EVA copolymers are thermoplastic hot-melt adhesives. They are typically manufactured in high pressure copolymerization processes. Hot melt thermoplastic material provides an advantage in that little or no solvent, especially organic solvent, need to be used to make a flowable casting material to make a layer of bisoprolol containing matrix. With a hot melt material, the bisoprolol can be dispersed evenly in the hot melt adhesive, or it can be completely dissolved therein without the presence of crystalline or particulate bisoprolol or its salts. EVA copolymers are conventionally considered to be copolymers of ethylene and vinyl acetate in which generally the weight percentage of ethylene in the polymer molecule is more than that of the vinyl acetate. Thus the vinyl acetate content is less than 50wt%. Generally, the vinyl acetate content is about 4wt% to 50wt%, preferably about 10wt% to 49wt%. For use as the carrier material in the bisoprolol reservoir, the vinyl acetate content is preferably about 35wt% to 45wt% vinyl acetate. A more preferred EVA is about 40wt% plus or minus 2wt% vinyl acetate. The vinyl acetate content and the molecular weight range influence adhesive properties and hot melt rheology. The higher the ethylene content, the more compatibility and adhesion the EVA has with nonpolar material such as polyolefms. We have found that the EVA with 30wt% or more, preferably about 35wt% to 45wt% vinyl acetate content are quite suitable for forming the drug reservoir for delivery of bisoprolol at a desirable flux and for a suitable period of delivery. Generally the EVA number represents the percent vinyl acetate in the EVA polymer, thus EVA40 has 40wt% vinyl acetate and EVA20 has 20wt% vinyl acetate, etc. The EVA polymer may optionally be modified by methods well known in the art, including modification with an unsaturated carboxylic acid or its derivatives, such as maleic anhydride or maleic acid.

[00050] EVA materials are commercially available from various suppliers, e.g.,

Minnesota Mining Co and DuPont (e.g., EL V AX^®). Methods for their preparation are, for example, described in US2,200,429 and US2,396,785. For the EVA of the present invention, EVA copolymers having vinyl acetate content of about 4 to 80% by weight of the total and a melt index of about 0.1 to 1000 grams per ten minutes can be used. Melt index is the number of grams of polymer that can be forced through a standard cylindrical orifice under a standard pressure at a standard temperature and thus is inversely related to a molecular weight, as determined by standard ASTM D 1238-65T condition E practice. The melt index for EVA for the reservoir is typically from about 0.3 to 100.

[00051] The device can include an in-line adhesive at a position more proximal to the body surface than the bisoprolol-containing reservoir. Further, the in-line adhesive can be put in for rate-controlling function to reduce the flux through the body surface. For example, the in-line adhesive can be the body-contacting adhesive layer that is disposed on the body- facing side of the bisoprolol-containing reservoir as shown in FIG. 1 and FIG. 2. Of course, more layers can be disposed on the body proximal side of the bisoprolol-containing reservoir either before a rate-control layer or after the rate- control layer. Preferably, the rate-control layer is the in-line body-contacting adhesive. Such a structure will facilitate the ease of making of the device, because fewer layers are included. The rate-control adhesive slows the flux of bisoprolol to a level that is suitable to deliver the drug at a therapeutically effective rate of greater than about lmcg/(cm²hr); preferably about 3mcg/(cm²hr) to 80mcg/(cm²hr), more preferably about 8mcg/(cm²hr) to 60mcg/(cm²hr). Without the rate-control adhesive, the flux would have been higher, unless another rate limiting layer is used.

[00052] The in-line, rate-control adhesive is preferably made of a material that is different from the bisoprolol-containing layer. Preferably the rate-control adhesive is made of polyisobutylene (PIB). PIB has excellent adhesive property and is suitable for retaining the device on body surface for 1-day delivery or multiple day delivery, i.e., 2- day, 3-day, etc., even up to 7-day delivery. PIB adhesives are mixtures of high molecular weight (HMW) PIB, low molecular weight (LMW) PIB, and/or plasticizer such as polybutene. Such mixtures are described in the art, e.g., US5508038. The molecular weight of the HMW PIB will usually be in the range of about 700,000 to 2,500,000 Da, whereas that of the LMW PIB will typically range from about 1,000 to about 90,000, preferably about from 35,000 to 50,000. The molecular weights referred to herein are weight average molecular weights. The weight ratio of HMW PIB to LMW PIB in the adhesive will normally range between about 1 : 1 to 1 :20, preferably about 1 :3 to 1 : 10. By adjusting the ratio of HMW and LMW PIB or using plasticizer, the rheo logical properties of the PIB adhesive can be tailored so that the desired adhesive properties can be achieved. Generally, higher amount of LMW PIB and the use of plasticizer will decrease modulus but increase cold flow.

[00053] In one type of embodiments, the adhesive composition of this invention contains the HMW and LMW PIB in weight ratios (HMW PIB : LMW PIB) in the range of about 3-40:97-60, preferably in the range of about 5-25:95-75 and most preferred in the range of about 10-20:90-80. The ratio of HMW PIB to LMW PIB that provides an optimal adhesive for a specific drug agent will be dependent upon the identity and concentration of agent being delivered. As an example, in one effective embodiment the PIB adhesive includes 5wt% HMW PIB material (such as OPPANOL L80, LlOO, and L 140 from BASF) and 95wt% LMW PIB material (Such as OPPANOL BlO, BI l, B12, and B13 from BASF). Such an exemplary PIB adhesive 2-3mil (0.05mm to 0.075mm) in thickness demonstrated rate-control when combined with a bisoprolol (35wt%) in EVA40 (ethylene -vinyl acetate copolymer with 40% vinyl acetate, such as EL V AX^® 4OW from DuPont) drug reservoir about 4-7mil (0.1 to 0.175mm) thick, resulting in bisoprolol base average flux of (5.5μg/cm²-h).

[00054] Optionally, modification of flux of the drug through the PIB can be effected by incorporating in the adhesive material such as micronized, crosslinked polyvinylpyrrolidone (PVP), such as CROSPOVIDONE (Kollidon CL-CY from BASF typically with bulk density between 0.2-0.3 g/cm3 and particle size D90 of 10-20 micron). Such PVP improves the permeability of bisoprolol material through the PIB layer. For example the 5:95 L100:B12 PIB adhesive was formulated to include 20wt% CROSPOVIDONE, from which an average bisoprolol base flux of 33.3μg/(cm²-h) was achieved.

[00055] Varying the amounts of CROSPOVIDONE in the PIB adhesive would result in fine-tuning the flux of bisoprolol to desired levels. For example, multilaminate formulations containing different PVP amounts were tested for the effect of such variation on flux through skin. The multilaminate formulations contained 35wt% of bisoprolol base in EVA40, an EVA12 as tie layer and PIB adhesive (5:95 L100:B12 PIB) with 12wt% or 18wt% PVP were tested. The formulation containing 12wt% PVP resulted in a flux of 5.4μg/(cm²h) whereas that from the formulation containing 18wt% PVP resulted in a flux of 7.5μg/(cm²h). A formulation containing 30wt% bisoprolol base and 15wt% PVP was also tested. The flux of bisoprolol formulation from this formulation was 6.3μg/(cm²h). This experiment indicated that the amount of PVP added in the PIB adhesive could be adjusted to change the flux of bisoprolol base to desired levels. PIB polymers are available commercially, e.g., under the tradename VISTANEX™ from Exxon Chemical. The amount of PVP in the resulting adhesive can be about lwt% to 30wt%, preferably about 5wt% to 25wt%, more preferably about 8wt% to 20wt%.

[00056] The term, "plasticizer" as used herein relating to PIB refers to compounds other than the agent being delivered, such as mineral oil, polybutene oil, and other low molecular weight hydrocarbons that act to plasticize PIB adhesives and increase their permeability to the agent being delivered. An adhesive composition is substantially free of plasticizer if it contains, at most, trace amounts of plasticizer and more preferably, no plasticizer. The term, "tackifier" as used herein relating to PIB refers to material, other than PIB, that is added to adhesives to increase their tack or stickiness. Such materials are typically naturally occurring resinous or resinous materials or synthetic polymer materials. An adhesive is substantially free of tackifier if it contains, at most, trace amounts of tackifier and preferably no tackifier. [00057] The PIB can be with or without tackifϊers or plasticizers, such as low molecular weight polybutene (e.g., INDOPOL H 1900 and/or high Tg, low molecular weight aliphatic resins such as the ESCOREZ resins available from Exxon Chemical, and the like). The body-contacting adhesive can be further modified to improve body surface adhesion. For example, a body-contacting adhesive containing 16wt% LlOO PIB, 24wt% OPPANOL B12 PIB, 40wt% INDOPOL H1900 polybutene, and 20wt% CROSPOVIDONE will provide superior body surface adhesion and continue to provide rate-control. Rate-control can be further adjusted by adjusting the body-contacting adhesive thickness, for example, by increasing the adhesive thickness to provide greater rate-control.

[00058] The thickness of the in-line adhesive layer (which optionally can also be rate-controlling) will generally be from about 0.5mil (0.127mm) to 6mil (0.154mm), preferably about 2mil (0.05 lmm) to 3mil (0.076mm). Although it is desired that the adhesive functions in rate-control, the composition and thickness of the adhesive layer is provided such that the adhesive layer does not constitute a significant permeation barrier to the passage of the agent to be delivered but act adequately for rate-controlling function if rate-control is desired in the adhesive. PIB is particularly useful in this respect. Unless a drug requires the use of a loading dose to rapidly saturate drug delivery sites in the skin, the adhesive thickness is also preferably selected so that the adhesive does not contain a substantial amount of drug agent and preferably less than about 15wt% of the total amount of the drug agent in the patch.

[00059] Yet another adhesive that can be used for in-line adhesive, which can be a body-contacting adhesive, is a polyacrylate (acrylic polymers), e.g., polyacrylate described in US patent publication US20040213832. A preferred type of polyacrylate is made from monomeric esters, preferably monomeric esters of alcohols that have 1 to 8 carbon atoms in the alcohol. Preferred alcohols include alkyl alcohol, hydroxyalkyl alcohol, methoxyalkyl alcohol and vinyl alcohol. A preferred monomeric ester has only one such 1 to 8 carbon atoms group from an alcohol and one organic group from an organic acid (e.g., acrylic acid and methacrylic acid). Examples of polyacrylate -based adhesives are as follows, identified as product numbers, manufactured by National Starch (Product Bulletin, 2000, DURO-TAK^® is a trademark of National Starch adhesives): 87-4098, 87-2287, 87-4287, 87-2516, 87-2051, 87-2052, 87-2054, 87-2196, 87-9259, 87-9261, 87-2979, 87-2510, 87-2353, 87-2100, 87-2852, 87-2074, 87-2258, 87-9085, 87-9301 and 87-5298. DURO-TAK^® 87-2287 and 87-4287 both are polymeric adhesives derived from monomer compositions that are similar: 5.2wt% 2-hydroxy ethyl acrylate, about 20-40wt% vinyl acetate, and about 55-75wt% 2-ethylhexyl acrylate; and these two polymeric adhesives are provided solubilized in ethyl acetate in solids content of about 40-50wt%. The DURO-TAK^® 87-4287 monomeric components consist of the above-mentioned three monomeric esters. The DURO-TAK^® 87-2287 adhesive is derived from monomeric components consisted of four monomers: vinyl acetate, 28%; 2-ethylhexyl acrylate, 67%; hydroxyethyl acrylate, 4.9%; and glycidyl methacrylate, 0.1%, see US5, 693,335. In certain workable embodiments, the adhesive has little or no acid functionality. Preferably it is substantially free of an adhesive polymer of acrylic acid or (meth) acrylic acid. In such adhesives, there is little or no adhesive that is polymerized from monomeric components of acrylic acid or (meth) acrylic acid. For example, the adhesive can have 4wt% or less of a polymer that is polymerized from acrylic acid or (meth) acrylic acid monomers. It is preferred that a polyacrylate adhesive be used with a rate-control tie layer such as EV A9 and/or EVA12, and/or EVAl 8.

[00060] Another kind of in-line body-contacting adhesive that can be used is a silicone adhesive. The silicone adhesives that may be used are typically high molecular weight poly dimethyl siloxanes or polydimethyldiphenyl siloxanes. Formulations of silicone adhesives that are useful in transdermal patches are described in U.S. Pat. Nos. 5,232,702, 4,906,169 and 4,951,622. One example of such a silicone adhesive is Silicone 4202 polydimethylsiloxane adhesive from Dow Corning. It is noted that other polysiloxane pressure sensitive adhesives can be used. Similar to the above in-line adhesives, the thickness can be adjusted by one skilled in the art based on whether the body-contacting adhesive is to have a rate-controlling function, in view of the present disclosure. EVA tie layer(s) can also be used with a silicone in-line body-contacting adhesive. [00061] Optionally, as mentioned, one or more tie layers can be included in the patch. To increase bonding of the EVA bisoprolol reservoir to the body-contacting adhesive (e.g., PIB) for secure attachment such that delamination can be prevented, the bisoprolol delivery device can include a tie-layer (or multiple layers if desired) of EVA with a vinyl acetate concentration less than that of the EVA in the bisoprolol reservoir, the vinyl acetate concentration being preferably about 8wt% or more and less than about 40wt%, preferably about 20wt% or less, more preferably about 9wt% to 20wt%, even more preferably about 9wt% to 18wt% (e.g., adhesive EVA12), even more preferably about 9wt% to 10wt%. The reduced vinyl acetate content in the tie layer compared to the drug reservoir improves the tie layer's compatibility with the nonpolar PIB or other nonpolar or less polar adhesives and results in a stronger bond than if an EVA with a higher vinyl acetate content is used. Such a tie layer was found by peel testing to provide increased bond strength to prevent delamination. It has been demonstrated through in-vitro flux testing that permeation is restricted by the inclusion of a lmil (0.025mm) EV A9 membrane between a bisoprolol reservoir (e.g., of EVA40) and a body-contacting adhesive (e.g., the PIB embodiments described above) more permeable than the EV A9. We have found that the use of a tie layer of a lmil (0.025mm) EVA12 membrane or EVAl 8 membrane between a bisoprolol reservoir (e.g., of EVA40) and a highly permeable body-contacting adhesive did not affect the permeation significantly. The thickness of the tie layer is preferably about 0.5mil (0.0.0127mm) to 5mil (0.0625mm), preferably about 0.5mil (0.0127mm) to 2mil (0.05mm), more preferably about 0.5mil (0.0127mm) to lmil (0.0254mm), more preferably about lmil (0.0254mm) to 2mil (0.05mm). Minimized thickness in the tie layer and selection of a tie layer that has little rate-controlling function is preferred if it is desired to reduce risk of rate-control effect, if any, caused by the tie-layer. Of course, if desired, one can design a device such that the material and the thickness of tie layer also contribute to the rate-controlling function, along with the rate-control adhesive (e.g., PIB).

[00062] Generally, an EVA tie layer is laminated to an EVA drug reservoir by heat pressing so that the tie layer and the drug reservoir fuse together. Adhesive is typically heat-cast on a separate carrier liner material. Then the EVA drug reservoir laminate and adhesive laminate are laminated together to obtain final product. Typically, the EVA drug reservoir is heat-cast on a carrier liner material first for easier processing as a laminate and then the laminate is further laminated with the tie layer by heat.

[00063] Further, if desired, one can use an in-line body-contacting adhesive that has less rate-controlling function and depend on the rate-control function of the tie layer to control the rate of bisoprolol delivery. For example, if the skin-contacting adhesive allows higher flux levels, additional rate-control could be added by modifying the tie- layer with reduced vinyl acetate content (such as using an EVA9, having 9wt% vinyl acetate) to reduce the drug transport rate. Further the tie-layer thickness can also be modified to affect the drug transport rate (thicker to reduce the transport, or thinner to increase the transport).

[00064] For forming the reservoir, an alternative polymer forms a gel-like reservoir (e.g., one with hydrogel polymer). Various drug reservoir compositions can be utilized according to this invention include aqueous and non-aqueous drug reservoir compositions. A typical general aqueous formulation is shown in Table 1.

Table 1

Reservoir components:

79.4% by weight water,

14.00% by weight of ethanol,

4.7% by weight of bisoprolol

1.9% by weight of gelling agent (Hydroxy ethyl cellulose)

[00065] Solvents used in the aqueous and non-aqueous systems include but are not limited to ethanol, isopropanol, butylene glycol, cremaphor EL, glycerol, isopropyl myristate, isopropyl palmitate, isopropyl stearate, diisopropyl adipate, labrafϊl, labrasol, oleic acid, mineral oil, myglyol, plurol oleic, propylene carbonate, propylene glycol, polyoxyethylene glycol (PEG), and silicone solvent like cyclomethicone, hexamethyldisiloxane, solutol, sorbitol or transcutol. For reservoir systems containing gels, the gelling agent can be CARBOSIL polyurethane elastomer, CARBOPOL polyacrylic acid polymer, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, klucel or other known gelling agents. In an aqueous reservoir, the bisoprolol can be formulated in an aqueous environment. Suitable polymers for the gel matrix can contain essentially any nonionic synthetic and/or naturally occurring polymeric materials. A polar nature is preferred, since bisoprolol base and its salts are polar, to promote compatibility and enhance agent solubility. Optionally, the gel matrix can be water swellable. Examples of suitable synthetic polymers include, but are not limited to, poly(acrylamide), poly(2-hydroxyethyl acrylate), poly(2-hydroxypropyl acrylate), poly(N-vinyl-2-pyrrolidone), poly(n- methylol acrylamide), poly(diacetone acrylamide), poly(2-hydroxylethyl methacrylate), poly( vinyl alcohol), and poly(allyl alcohol). Hydroxyl functional condensation polymers (i.e., polyesters, polycarbonates, polyurethanes) are also examples of suitable polar synthetic polymers. Polar naturally occurring polymers (or derivatives thereof) suitable for use as the gel matrix are exemplified by cellulose ethers, methyl cellulose ethers, cellulose and hydroxylated cellulose, methyl cellulose and hydroxylated methyl cellulose, gums such as guar, locust, karaya, xanthan, gelatin, and derivatives thereof. Typically, the weight percentage of the matrix polymer used to prepare gel matrices for the reservoirs of the electrotransport delivery devices, in certain embodiments of the methods of the invention, is about 10wt% to about 30wt%, preferably about 15wt% to about 25wt%.

[00066] An in-line, body-contacting adhesive can be disposed on the body surface proximal side of the hydrogel layer to secure the patch on the skin by adhesion. For example, an EVA tie layer can be placed between the hydrogel reservoir and a silicone adhesive to facilitate the adhesion of the nonpolar silicone adhesive to the polar hydrogel. Alternatively or additionally if desired, an overlay with adhesive can be disposed as the top layer of the device for attaching the device on the skin. By controlling the flux by means of the size, thickness of the reservoir and the tie layer, if any, and the drug loading in the reservoir, devices can be made such that an in-line adhesive is not needed. [00067] Yet another matrix material for the reservoir for holding the drug bisoprolol or a salt thereof is polyacrylate. The preferred polyacrylate (acrylic polymers) are comprised of a copolymer or terpolymer comprising at least two or more exemplary components selected from the group comprising acrylic acids, alkyl acrylates, methacrylates, copolymerizable secondary monomers or monomers with functional groups. Examples of monomers include, but are not limited to, vinyl acetate, acrylic acid, methacrylic acid, methoxyethyl acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylbutyl acrylate, 2-ethylbutyl methacrylate, isooctyl acrylate, isooctyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, acrylamide, dimethylacrylamide, acrylonitrile, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, tert-butylaminoethyl acrylate, tert-butylaminoethyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, glycidal methacrylate, and the like. A preferred type of polyacrylate is made from monomeric esters, preferably monomeric esters of alcohols that have 1 to 8 carbon atoms in the alcohol. Preferred alcohols include alkyl alcohol, hydroxyalkyl alcohol, methoxyalkyl alcohol and vinyl alcohol. A preferred monomeric ester has only one such 1 to 8 carbon atoms group from an alcohol and one organic group from an organic acid (e.g., acrylic acid and methacrylic acid). Additional examples of appropriate acrylic adhesives suitable in the practice of the invention are described in Satas, "Acrylic Adhesives," Handbook of pressure-Sensitive Adhesive Technology, 2nd ed., pp. 396-456 (D. Satas, ed.), Van Nostrand Reinhold, New York (1989). The acrylic adhesives are commercially available (National Starch and Chemical Corporation, Bridgewater, NJ; Solutia, MA). Further examples of polyacrylate-based adhesives are as follows, identified as product numbers, manufactured by National Starch (Product Bulletin, 2000, DURO-TAK^® is a trademark of National Starch adhesives): 87-4098, 87-2287, 87-4287, 87-5216, 87-2051, 87-2052, 87-2054, 87-2196, 87-9259, 87-9261, 87-2979, 87-2510, 87-2353, 87-2100, 87-2852, 87-2074, 87-2258, 87-9085, 87-9301 and 87-5298. DURO-TAK^® 87-2287 and 87-4287 both are polymeric adhesives derived from monomer compositions that are similar: 5.2wt% 2-hydroxyethyl acrylate, about 20-40wt% vinyl acetate, and about 55-75wt% 2-ethylhexyl acrylate; and these two polymeric adhesives are provided solubilized in ethyl acetate in solids content of about 40-50wt%. The DURO-TAK^® 87-4287 monomeric components consist of the above- mentioned three monomeric esters. The DURO-TAK^® 87-2287 adhesive is derived from monomeric components consisted of four monomers: vinyl acetate, 28%; 2- ethylhexyl acrylate, 67%; hydroxyethyl acrylate, 4.9%; and glycidyl methacrylate, 0.1%, see US5,693,335.

[00068] In certain workable embodiments, the adhesive in the reservoir has little or no acid functionality. Preferably it is substantially free of an adhesive polymer of acrylic acid or (meth) acrylic acid. In such adhesives, there is little or no adhesive that is polymerized from monomeric components of acrylic acid or (meth) acrylic acid. For example, the adhesive can have 4wt% or less of a polymer that is polymerized from acrylic acid or (meth) acrylic acid monomers.

[00069] The polyacrylate material forming the reservoir has a solubility for the drug of about 0.5wt% to about 15wt% of the total polymer composition; preferably about lwt% to about 10wt%; more preferably about 2wt% to about 8wt% of the total polymer composition 4. The reservoir, with or without the body-contacting adhesive, has a thickness of about 0.0125 mm (0.5 mil) to about 0.1 mm (4 mil); preferably about 0.018 mm (0.75 mil) to about 0.088 mm (3.5 mil); more preferably 0.023 mm (0.9 mil) to about 0.075 (3 mil); and even more preferably about 0.025 mm (1.05 mil) to about 0.05 mm (2 milO).

[00070] Such acrylates can also be used as an in-line body surface contacting

(i.e., body-contacting) adhesive for attaching the device to the body surface during the use of the device. The thickness can be adjusted by one skilled in the art based on whether the acrylate body-contacting adhesive is to have a rate-controlling function.

[00071] As previously mentioned, another kind of in-line body-contacting adhesive that can be used is a silicone adhesive. The silicone adhesives can be used as a reservoir for bisoprolol also, e.g., 4202 polydimethylsiloxane adhesive from Dow Corning. It is noted that other polysiloxane pressure sensitive adhesives can be used. Similar to the above in-line adhesives, the thickness can be adjusted by one skilled in the art based on whether the body-contacting adhesive is to have a rate-controlling function, in view of the present disclosure.

[00072] If desired, one can implement rate-control with a traditional "plastic" type of rate-control material such as polyolefm, e.g., polyethylene (high density, medium density or low density polyethylene, i.e., LDPE, etc.). However, in certain embodiments, for a desirable profile and ease of manufacturing, it is preferred that such plastic rate-control membrane is not used and/or the tie layer be implemented only to attach the layers together without imparting substantial rate-controlling function.

[00073] Optionally, in one embodiment, the transdermal system can include a rate-control membrane placed between the reservoir and the body-contacting adhesive layer. Examples of rate-control membrane include but are not limited to EVA, high density polyethylene, and low density polyethylene. Examples of the types of polymer films that may be used to make the rate-control membrane are disclosed in U.S. Pat. Nos. 3,797,494 and 4,031,894, both of which are incorporated herein by reference. The above-mentioned EVA tie-layer can function as such a rate-control membrane for controlling flux rate of bisoprolol delivery.

[00074] Although no permeation enhancer (which includes absorption promoter) is needed in the present invention in that adequate bisoprolol flux can be achieved without permeation enhancer, if desired, permeation enhancer(s) can be used for further increasing the skin permeability of the drug bisoprolol or drug combinations to achieve delivery at therapeutically effective rates. Permeation enhancer(s) can be applied to the skin by pretreatment or currently with the drug, for example, by incorporation in the reservoir. A permeation enhancer should have the ability to enhance the permeability of the skin for one, or more drugs or other biologically active agents. A useful permeation enhancer would enhance permeability of the desired drug or biologically active agent at a rate adequate for therapeutic level from a reasonably sized patch (e.g., about 20 to 80cm²).

[00075] Useful permeation enhancers include anionic surfactants (e.g. sodium lauryl sulfate, N-Lauryl Sarcosine, sodium octyl sulfate; cationic surfactants (e.g. cetyl trimethyl ammonium bromide, dodecyl pyridinium chloride, octyl trimethyl ammonium bromide); zwitterionic surfactants (like hexadecyl trimethyl ammoniopropane sulfonate, oleyl betaine, cocamidopropyl betaine); nonionic surfactants (e.g. polyoxyethylene sorbitan monolaurate (TWEEN20), sorbitan monolaurate, polyethyleneglycol dodecyl ether, Triton X-IOO); fatty acids (e.g. Oleic Acid, linoleic acid, linolenic acid); fatty esters (e.g. isopropyl myristate, sodium oleate, methyl laurate); azone/azone-like compounds (N-decyl-2-pyrrolidone, dodecyl amine, PP, nicotine sulfate); and others (e.g., menthol, methyl pyrrolidone, cineole, limonene). One or more permeation enhancers, alone or in combination, and which may include dissolution assistants, can constitute about 0 to 40% by weight, preferably about 0 to 30% by weight, and more preferably less than about 15% by weight solids of the resulting reservoir that has adequate pressure sensitive adhesive properties. In certain embodiments, the amount of permeation enhancers of about 15wt% or less, preferably about 9wt% or less, preferably about 5wt% or less, and preferably none is used in the bisoprolol-containing reservoir. Also, although alkaline salts (e.g., sodium salts, potassium salts, ammonium salts, etc.) of organic acids such as acetic acid, lactic acid, citric acid, etc., can be used to increase bisoprolol absorption if desired, they are not necessarily used and in some embodiments, such organic salts are not used. Preferably about 10wt% or less, preferably about 4wt% or less of such salts (e.g., sodium acetate) is used. Although not needed, if it is desired to increase permeation and if any permeation enhancer is used, PVP is preferred, and no other permeation enhancers, such as fatty acids, alcohols, esters (such as esters of fatty acids) needs to be added. The PVP is preferably added into the in-line adhesive (e.g., PIB) and not in the drug reservoir layer.

[00076] The reservoir system according to this invention comprising bisoprolol can also contain other drugs, such as ACE inhibitors, beta blockers, calcium channel blockers, diuretics, direct potassium sparing agents, direct vasodilators, adrenergic inhibitors, alpha blockers, and potassium channel activators. Examples of ACE inhibitors include but are not limited to enalapril, benazepril, ramipril, quinalapril, captopril, lisinopril, trandolapril, and zofenopril. Examples of Angiotensin-II -receptor antagonists include but are not limited to losartan, valsartan, irbesartan, candesartan, olmesartan, telmisartan, and eprosartan. Examples of beta blockers include but are not limited to carvedilol, metoprolol, betaxolol, nebivolol, carteolol, mepindolol, penbutolol, pindolol, acebutolol, atenolol, nadolol, timolol, propanolol, solatol, labetolol, levobunolol, and metipranolol. Examples of calcium channel blockers include but are not limited to amlodipine, felodipine, nicardipine, nifedipine, nimodipine, nisoldipine, nitrendipine, lercanidipine, lacidipine, gallopamil, verapamil, and diltiazem. Examples of diuretics include but are not limited to chlorthalidone, hydrochlorthiazide, hydrodiuril, microzide, esidrix, indapamide, metolazone, zaroxolyn, bumetanide, ethacrynic acid, furosemide, and torsemide. Examples of potassium sparing agents include but are not limited to amiloride hydrochloride, spironolactone, and triamterne. Examples of direct vasodilators include but are not limited to hydralazine hydrochloride, minoxidil, and pinacidil. Examples of adrenergic inhibitors include but are not limited to reserpine, clonidine, guanabenz acetate, guanfacine, and methyldopa. Examples of alpha blockers include but are not limited to doxazosin, prazosin, and terazosin. Examples of potassium channel activators include but are not limited to nicorandil. Examples of statins include but are not limited to atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin, and simvastatin.

[00077] In one embodiment the present invention provides a method of treatment of hypertension, migraine, and CHF, etc., in which the bisoprolol is administered transdermally, whereas the ACE inhibitor, the second beta blocker, the calcium channel blocker, the diuretic, the direct potassium sparing agent, the direct vasodilator, the adrenergic inhibitor, the alpha blocker, or the potassium channel activator is administered orally in conjunction. Another embodiment in this invention comprises of a method of treatment of hypertension, migraine, or CHF, etc., in which the bisoprolol is administered transdermally, whereas the ACE inhibitor, the calcium channel blocker, the diuretic, the direct potassium sparing agent, the direct vasodilator, the adrenergic inhibitor, the alpha blocker, or the potassium channel activator is administered by other routes of administration in conjunction, including but not limited to intravenous, intra ocular, intranasal and pulmonary, rectal, vaginal, sublingual, and the like. Beta blockers can also be used for prophylaxis of migraine.

[00078] Transdermal delivery patches typically have protective layers or release liners. For example, as shown in FIGS 1 and 2, the patch 1 includes a peelable protective layer (or liner) 5. The protective layer 5 is made of a polymeric material that may be optionally metallized. Examples of the polymeric materials include polyurethane, polyvinyl acetate, polyvinylidene chloride, polypropylene, polycarbonate, polystyrene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, paper, and the like, and a combination thereof. In preferred embodiments, the protective layer includes a siliconized polyester sheet.

[00079] The backing layer 2 can be made with conventional materials. It may be formed from any material suitable for making transdermal delivery patches, such as a breathable or occlusive material including fabric or sheet, made of polyvinyl acetate, polyvinylidene chloride, polyethylene, polyurethane, polyester, EVA, polyethylene terephthalate (PET), polybutylene terephthalate, coated paper products, aluminum sheet and the like, or a combination thereof. In preferred embodiments, the backing layer includes low density polyethylene (LDPE) materials, medium density polyethylene (MDPE) materials or high density polyethylene (HDPE) materials, e.g., SARANEX (Dow Chemical, Midland, Mich.). The backing layer may be a monolithic or a multilaminate layer. In preferred embodiments, the backing layer is a multilaminate layer including nonlinear LDPE layer/linear LDPE layer/nonlinear LDPE layer. A preferred backing material is a laminate of a thin occlusive PET or equivalent film tied to an EVA film. For a PET/EVA laminate backing, preferably the EVA side is facing the reservoir. Preferably the EVA in the backing contains 20wt% or less of vinyl acetate content, more preferably about 12wt% of vinyl acetate. Preferably the vinyl acetate content is about similar or within 5wt% of the vinyl content (inwt%) of the tie layer (if any) that is disposed between the reservoir and any in-line adhesive. The backing layer can have a thickness of about 0.012mm (0.5mil) to 0.125mm (5mil); preferably about 0.025mm (lmil) to 0.1mm (4mil); more preferably about 0.0625mm (1.5mil) to 0.0875mm (3.5mil).

[00080] To further improve body surface adhesion, optionally, an overlay adhesive can also be used. Typically an overlay is a layer of material positioned at the top (i.e., the side most distal from the body surface during application) of the device with adhesive on the body-proximal side of the overlay. The overlay has a size slightly larger in area than the reservoir in the device (which as a patch has a generally flat configuration) such that there is a ring-shaped overhang (or border) of the overlay around the device for the adhesive on the overhang to adhere securely to the body surface. An overlay can have an aggressive body-contacting adhesive, such as one with 16wt% LlOO PIB, 24wt% OPPANOL B 12 PIB, 40wt% INDOPOL H 1900 polybutene, and 20wt% CRO SPOVIDONE. This adhesive is applied to a backing material, such as the 3M SCHOTCHPAK 9732 backing film previously described, or a non-woven elastomeric backing material. The overlay adhesive is cut to be larger than the active component of the patch (as described above), for example 2cm longer in each linear dimension for a rectangular patch, and 2cm longer in diameter for a circular patch. The overlay is laminated into place over the active component of the patch during manufacturing, held in place by the adhesive, and centered so as to provide, in this example, a lcm border around the patch perimeter for improving adhesion security of the system on the body surface.

[00081] Compatibility of the overlay adhesive and reservoir matrix material containing the drug can be further improved by interleaving a thin occlusive film therebetween. FIG. 3 shows an embodiment with such an occlusive film. In FIG. 3, the transdermal drug delivery device 1 includes a drug reservoir 3 disposed on a backing layer 2, a body-contacting adhesive 6, and a peelable (removable) protective layer 5 (or release liner). The reservoir 3 contains bisoprolol and optionally other drugs and the carrier material in the reservoir is suitable for carrying the pharmaceutical agents (or drugs) for transdermal delivery. Another adhesive layer 12 is disposed on a backing 14 forming an overlay 16 more distal from the protective layer release liner 5.

[00082] To prevent the migration of bisoprolol from the reservoir 3 to the adhesive 12 of the overlay 16, a barrier frame 18 with a shape resembling a window- frame for a rectangular patch or a "O" for a circular patch with internal dimensions smaller than that of the active area and outer dimensions greater than that of the area of the reservoir 3 is placed between the reservoir 3 and the overlay adhesive 12. In this embodiment of FIG. 3, the barrier frame 18 is disposed between the overlay adhesive layer 12 and the backing layer 2 of the drug reservoir 3. FIG. 4 is an isometric plan view of the barrier frame 18. The reservoir 3 has an outer perimeter (or edge) that is between the inner perimeter 20 and outer perimeter 22 of the barrier frame 18. The width (i.e., the distance between the inner perimeter 20 and outer perimeter 22) of the barrier frame 18 is selected, considering the cold flow characteristics and expected shelf life of the device, such that the barrier frame will prevent cold flow reservoir material to migrate past the outer perimeter 22 to contact the overlay adhesive 12. As used herein, the term "between" means only that something is in a position intermediate two other things and does not necessarily mean that it is immediately adjacent to them or contacting them, unless specified to be the case. The border of the barrier frame 18 that extends outside of the area of the reservoir 3 is typically 1 to 5mm, preferably about 2- 3mm. Aligned between the active area and overlay adhesive, the interleaving frame ensures that even with some flow of adhesive or reservoir material from the active area during storage and wear, the adhesive from the overlay shall not come into contact with the reservoir material or adhesive proximal to the body surface and cause undesired drug migration.

[00083] The barrier material for making the backing layer can also be used for making the barrier frame. The barrier layer is impermeable to the drug in the reservoir; and preferably includes a material that is insoluble in water, alcohol and organic solvents. The barrier layer can be made from a polymer such as polyolefm laminates (Dow Chemical, Midland, Mich.), acrylonitrile copolymer films (BAREX, BP Chemicals, KoIn, Germany), polyethylnapthalene (PEN), polyethylene terephthalate (PET), polyimide, polyurethane, polyethylene, polyvinyl acetate, polyvinylidene chloride, polybutylene terephthalate, coated paper products, metallized films and glass coated films where these films can include ethylene copolymers such as EVA, and combinations thereof. In preferred embodiments, the barrier layer contains polyester such as PET laminated to a polymer such as polyurethane, polyethylene, and ethylene copolymers. In preferred embodiments, the barrier layer contains polyester such as PET laminated to ethylene copolymers such as EVA. Other materials can be used, as long as the active agent or permeation enhancers are insoluble in them. The barrier layer as a single layer or as a multilaminate layer has a thickness of about 0.075mm (0.3mil) to about 0.125mm (5mil); preferably about 0.025mm (lmil) to about 0.1mm (4mil); more preferably about 0.0625mm (1.5mil) to about 0.0875mm (3.5mil); and even more preferably about 0.025mm (lmil) to about 0.05mm (2mil). [00084] Transdermal flux can be measured with a standard procedure using Franz cells or using an array of formulations. Flux experiments were done on isolated human cadaver epidermis. With Franz cells, in each Franz diffusion cell a disc of epidermis is placed on the receptor compartment. A transdermal delivery system is placed over the diffusion area (1.98cm²) in the center of the receptor. The donor compartment is then added and clamped to the assembly. At time 0, receptor solution (between 21cm and 24ml, exactly measured) is added into the receptor compartment and the cell maintained at 35⁰C. This temperature yields a skin surface temperature of 30-32⁰C. Samples of the receptor compartment are taken periodically to determine the flux through skin and analyzed by HPLC. An alternative way to test flux is to use an array of patches. In testing flux with an array of transdermal miniature patches, formulations are prepared by mixing stock solutions of each of the mixture components of formulation in organic solvents (about 15wt% solids), followed by a mixing process. The mixtures are then aliquoted onto arrays as 4-mm diameter drops and allowed to dry, leaving behind solid samples or "dots." (i.e., mini-patches). The miniature patches in the arrays are then tested individually for flux through skin using a permeation array, whose principle of drug flux from a patch formulation through epidermis to a compartment of receptor medium is similar to that of Franz cells (an array of miniature cells). The test array has a plurality of cells, a piece of isolated human epidermis large enough to cover the whole array, and a multiple well plate with wells acting as the receptor compartments filled with receptor medium. The assembled permeation arrays are stored at 32 ⁰C and 60 % relative humidity for the duration of the permeation experiments. Receptor fluid is auto-sampled from each of the permeation wells at regular intervals and then measured by HPLC to determine the flux of the drug.

[00085] A wide variety of materials that can be used for fabricating the various layers of the transdermal delivery patches according to this invention have been described above. It is contemplated that materials other than those specifically disclosed herein, including those that may hereafter become known to the art to be capable of performing the necessary functions can be used by those skilled in the art. Administration of the Drug

[00086] On application to the skin, the drug in the drug reservoir of the transdermal patch diffuses into the skin where it is absorbed into the bloodstream to produce a systemic therapeutic effect. The onset of the therapeutic depends on various factors, such as, potency of the drug, the solubility and diffusivity of the drug in the skin, thickness of the skin, concentration of the drug within the body surface application site, concentration of the drug in the drug reservoir, and the like. On repeated sequential applications (by replacing a used patch with a new one), the residual drug in the application site of the patch is absorbed by the body at approximately the same rate that drug from the new patch is absorbed into the new application area.

[00087] Administration of the drug from a patch can be maintained for one day or a few days, e.g., at least three days, and up to seven days. It has been known in the past that beta blockers may tend to cause skin irritation or skin sensitization. See, e.g., B. F. O'DONNELL, I. S. FOULDS (1993) Contact allergy to beta-blocking agents in ophthalmic preparations Contact Dermatitis 28 (2), 121-122; Circulation. 1995 Nov; 1;92(9):2526- 39; and "Sensitization of human atrial 5-HT4 receptors by chronic beta-blocker treatment", Sanders L, Lynham JA, Bond B, del Monte F, Harding SE, Kaumann AJ; 1 : Biol Pharm Bull. 1997 Apr; 20(4): 421-7.

[00088] In the present invention, we have discovered a transdermal delivery device having a formulation that can deliver bisoprolol with no detectable irritation on skin. Additionally, we have also discovered that bisoprolol free base does not cause skin sensitization. As such, it can be considered to be "skin-compatible" or "biocompatible".

Methods of Manufacture

[00089] The transdermal devices are manufactured according to known methodology of laying adhesive on a backing and laminating different layers together. For example, in an embodiment, a solution of the polymeric reservoir material, as described above, is added to a double planetary mixer, followed by addition of desired amounts of the drug, and other ingredients that may be needed. Preferably, the polymeric reservoir material is an EVA hot melt material. Methods of hot melt processing and laminating to form transdermal devices are known to those skilled in the art. Generally, hot melt adhesives are processed at temperatures above room temperature, e.g., about or above 40⁰C, in melted condition to incorporate the drug and other excipients, and subsequently solidify to form the drug containing layer with adhesive and cohesive forces. The cohesive forces generally decrease with decreasing softening temperatures of the hot melt adhesives. Using plasticizers can lower the softening temperature of the hot melt material. A hot melt adhesive material, after melting and homogenizing with the desired drug at a temperature, can be spread onto a carrier material before cooling. A knife coating technique can be used to spread the hot melt mix on to a carrier surface for subsequently laminating with other layers.

EXAMPLES

[00090] Below are examples of specific embodiments for carrying out the present invention. The examples are for illustrative purposes only, and are not intended to limit the scope of the present invention in any way. In the following examples all percentages are by weight unless noted otherwise.

EXAMPLE 1

Making Bisoprolol Patches

[00091] A drug reservoir having 65wt% EVA40 was obtained by melt blending with 35wt% bisoprolol base. A 6g batch was prepared by adding EVA40 pellets slowly to a 40⁰C twin-blade mixer at 11-12 rpm. EVA addition was done over a period of 1-7 minutes, followed by additional mixing for 7-8 minutes. Bisoprolol base was then added dropwise over a period of 10-30 minutes into EVA mixture under continuous mixing. The mixture was blended for up to 40 minutes to achieve homogeneity, before removal from the mixer. The blended material was calendared to various thicknesses of 20mil (0.5mm) or more between release-coated PET liners (such as SCOTCHPAK 1020 or siliconized PET release liners) at a speed of 0.2fpm (6cm/m) with a roll temperature of 192°F (89°C). The drug reservoir films were then laminated between the EVA face of a PET/EVA laminate film (3M SCOTCHPAK 9733) and a lmil (0.025mm) film of EVA12 at 0.4foot /min (fpm), i.e., 12cm/min, with a roll temperature of 192°F (89°C). A PIB adhesive of 4% LlOO, 84% B 12, and 12% dry basis CROSPOVIDONE (Kollidon CL-CY from BASF typically with bulk density between 0.2-0.3 g/cm3 and particle size D90 of 10-20 micron) was prepared in a solution of hexane and cast onto a siliconized PET release liner (REXAM, Grade 10393 S 3mil (0.075mm) CL PET Al 0/000) and dried (90 minutes at 65°C) to produce a thing film, which was laminated to the EVA 12 tie-layer of the tie-layer/drug reservoir/backing trilaminate. Finally, this laminate was die-cut to produce individual systems. Bisoprolol patches with thinner reservoirs could also e made, e.g., with reservoirs of 1-lOml thickness.

EXAMPLE 2

Making Bisoprolol Patches of a Formulation

[00092] Using the materials and methods identified in Example 1 , a drug reservoir was produced containing 50wt% bisoprolol base in EVA40. This drug reservoir was assembled between a PET/EVA backing film and 2mil (0.05mm) EVA9 rate-control tie-layer. This backing material was laminated to a PIB adhesive film containing 8.5wt% LlOO, 28.9% B12, 47.6wt% H18000 Polybutene and 15wt%

CROSPOVIDONE.

EXAMPLE 3

Flux with Biosoprolol in EVA reservoir

[00093] Multiple skin permeation studies were performed to determine the patch formulations that would render sufficient flux of bisoprolol base such that the dose is therapeutically effective for treatment of hypertension. Skin permeation studies were performed with the isolated epidermal layer of human cadaver used to quantitatively determine the permeation of bisoprolol base. Non-hairy, human cadaver skin was cleaned of all fat and extraneous materials. The skin was then rinsed and placed into a beaker with distilled water, first at 35°C for 5 minutes, then at 6I⁰C for 1 minute. The epidermis was carefully separated from the dermis and inspected for holes. Discs of epidermis were die-cut using a 1 3/6 in (i.e., 3.65cm) diameter arch punch. The epidermis was then stored stratum corneum side up, and kept hydrated at 4°C before use, typically the next day. A buffer of 0.05M KH₂PO₄/KHPO₄, pH 6.5 with 1% cyclodextrin was used as the receptor medium. Medium (diffusion area: 1.98cm²) vertical Franz diffusion cells were used. For each cell, a disc of epidermis (size 3.65cm diameter) was placed on the receptor compartment. The formulation of bisoprolol base (1.98cm²) was directly added on top of the skin. At time zero, the receptor solution (between 21ml and 23ml) was added into the receptor compartment and the cell was placed in a shaking water bath set at 35°C. This temperature yielded a skin surface temperature of 30-32⁰C. For each skin donor, five replicates were used. Receptors were sampled at 6, 24, 36, 48 and 72 hours from the start of the experiment (full volume of receptor solution was taken out and replenished with fresh buffer). The aliquoted receptor solution was assayed by HPLC at each time point.

Flux Study To Determine Rate-control by Different Tie Layers [00094] All the formulations tested were multilaminate patches containing

25wt% of bisoprolol base in EVA40 (meltmix) with a tie layer and National Starch DURO-TAK^® 87-4287 as in-line body-contacting adhesive. The objective of this study was to determine whether EV A9, EVA12, and EVAl 8 would provide rate-control while being used as a tie layer between the EVA40 reservoir and the contact adhesive. Additionally, effort was made to determine whether the thickness of the tie layer had an effect in providing rate-control. The formulations compared in this study were 25wt% bisoprolol base in EVA40 with 87-4287 adhesive (no tie layer), 25wt% bisoprolol base in EVA40 with lmil (0.025mm) EVAl 8 and 87-4287 adhesive, 25wt% bisoprolol base in EVA40 with 2mil (0.05mm) EVAl 8 and 87-4287 adhesive, 25wt% bisoprolol base in EVA40 with lmil EVA12 and 87-4287 adhesive, 25wt% bisoprolol base in EVA40 with lmil EV A9 and 87-4287 adhesive and 25wt% bisoprolol base in EVA40 with 2mil EV A9 and 87-4287 adhesive. Table 2 below represents the flux of bisoprolol base of each of the above-mentioned formulations.

Table 2

[00095] The comparative flux data for the formulations containing different tie layers is shown in the table above. The number of tests done for each formulation was 5 (n=5). Using EVA reservoir and DURO-TAK^® 87-4287 as contact adhesive, the flux would be a little too high to be used without an additional rate-control layer. An EVA tie layer with less vinyl acetate content than EVA40 can be used to control the flux of bisoprolol. The results indicated that EV A9 tie layer at both thicknesses of 1 and 2mil provided sufficient rate-control while the rate-control was substantially less for EVAl 8, whereas EVA12 tie layer provided insufficient rate-control. Thus, it is preferred that the tie layer be an EVA material with about 10wt% or less of vinyl acetate, more preferably about 9wt% or less of vinyl acetate. Therefore, for a multilaminate patch containing a lmil EV A9 as the tie layer and DURO-TAK^® 87-4287 as contact adhesive, a 5cm² patch would provide sufficient flux to yield a therapeutic dose of 5mg/day. Likewise, for the same formulation, a patch size of 10cm² would provide a therapeutic dose of 10mg/day. Flux Study on Rate-control with EV A9 Tie Layer and PIB adhesives [00096] The invention describes a bisoprolol patch that can be used for extended periods of time, e.g., 3 days or 7 days for use on treatment of hypertension or for prophylaxis of migraine. Therefore the body-contacting adhesive needs to be one that would adhere well for the entire duration of use. PIB has excellent adhesive property and is suitable for retaining the device on body surface for multiple-day delivery, i.e., 3 days, etc., even up to 7 days. Additionally, PVP was added to further facilitate extended wear. For patches that would be used for extended multiple-day wear, increasing the drug loading would result in a reasonably thin patch. The objective of the following skin permeation study was to determine how much rate-control can be obtained by lmil EV A9 and PIB adhesive for a reservoir containing 35wt % drug. Also, the impact on flux by the addition of PVP to PIB from the same reservoir and the impact on flux by the addition of an EV A9 tie layer were studied.

[00097] All the formulations tested were multilaminate patches containing

35wt% of bisoprolol base in EVA40 (melt-mix). The PIB adhesive used for the study was a 95:5 weight ratio of LMW B 12 and HMW LlOO. The formulations involved in this study were 35wt% bisoprolol base in EVA40 with PIB adhesive (no tie layer); 35wt% bisoprolol base in EVA40 with lmil EVA9 tie layer and PIB adhesive; 35wt% bisoprolol base in EVA40 with PIB (without tie layer) and 20wt% PVP (CROSPOVIDONE) in the PIB adhesive; and 35wt% bisoprolol base in EVA40 with lmil EV A9 tie layer, PIB adhesive with 20wt% PVP. Table 3 represents the flux of bisoprolol base for each of the above-mentioned formulations.

Table 3

[00098] The above Table 3 results indicate that patches with EVA40 reservoir and PIB adhesive without a tie layer resulted in rate-controlled flux, showing that PIB functioned well in controlling flux of bisoprolol. However, in a system without an EVA tie layer, the inclusion of 20wt% PVP in the PIB adhesive increased the flux substantially, showing that PVP facilitated permeation of the drug through the PIB adhesive. The flux results of the first three formulations of Table 3 are also shown in FIG. 10. The top curve with the triangle data points is the 35% bisoprolol base in EVA40 with skin-contacting PIB adhesive and 20% PVP in the PIB adhesive. The middle curve with the diamond data points is the 35% bisoprolol base in EVA40 with skin-contacting PIB adhesive. The bottom curve with the square data points is the 35% bisoprolol base in EVA40 reservoir, with EV A9 (lmil, i.e., 0.025mm) tie layer and skin-contacting PIB adhesive (2 mil, i.e., 0.05mm). The vertical lines represent the standard deviation values from the averages. The number of tests done for each formulation was 5 (n=5). The result also shows that multilaminate patches with lmil EV A9 tie layer and a skin-contacting adhesive with PIB and PVP provided sufficient rate-control. This showed that the EV A9 tie layer was effective in controlling the rate of flux. Therefore for a multilaminate patch containing a lmil EV A9 as the tie layer and PIB with 20wt % PVP as a skin-contacting adhesive, a 33 cm² patch would provide sufficient flux to yield a therapeutic dose of 5mg/day. Likewise, for the same formulation, a patch size of 66cm² would provide a therapeutic dose of 10mg/day. Effective patches can also be made with EVA40 reservoir with PIB as the rate-control adhesive, with or without a tie layer. Further, it is contemplated that the PIB rate- control adhesive can be used in conjunction with other adhesives as the body-contacting adhesive, such as polyacrylate adhesive or silicone adhesive, and more than one tie layers can be used, e.g., using layers of EVA9, EVA12, EVA18, etc. alone or in combination.

[00099] Although permeation enhancer is not needed to provide useful flux of the bisoprolol drug, if it is desired to increase permeation and if any permeation enhancer is applied, PVP can be used (preferably in the in-line skin-contacting adhesive), and no other permeation enhancers, such as fatty acids, alcohols, esters (such as esters of fatty acids) needs to be added. Thus, the drug reservoir layer need not have any permeation enhancer. IfPVP is included, the PVP can thus be in the layer that is in-line (in the direct path of the drug from the drug reservoir to the body surface, rather than in the drug layer or in a layer more distal to the drug layer. Of course, the PVP can be included in the drug layer or in a layer more distal to the drug layer if desired.

EXAMPLE 4

Making Bisoprolol Laminate Patch with Silicone in-line Adhesive [000100] A drug reservoir having 65wt% EVA40 is obtained by melt-blending (or melt-mixing) with 35wt% bisoprolol base. A 6g batch is prepared by adding EVA40 pellets slowly to a 40⁰C twin-blade mixer at 11-12 rpm. EVA addition is done over a period of 1-7 minutes, followed by additional mixing for 7-8 minutes. Bisoprolol base is then added dropwise over a period of 10-30 minutes into EVA mixture under continuous mixing. The mixture is blended for up to 40 minutes to achieve homogeneity, before removal from the mixer. The blended material is calendared to various thicknesses of 20mil (0.5mm) or more between release-coated PET liners at a speed of 0.2fpm (6cm/m) with a roll temperature of 192°F (89°C). The drug reservoir films are then laminated between the EVA face of a PET/EVA laminate film (3M SCOTCHPAK 9733) and a lmil (0.025mm) film of EVA12 at 0.4foot /min (fpm), i.e. 12cm/min, with a roll temperature of 192°F (89°C). A silicone adhesive thin film cast can be prepared by casting a solvent dispersion (such as ethyl acetate or toluene) of polydimethylsiloxane and silicate resin onto a siliconized PET release liner (REXAM, Grade 10393 S 3mil (0.075mm) CL PET Al 0/000) and dried (90 minutes at 65°C) to produce a thin film, which is laminated to a EVA9 tie-layer of the tie-layer/drug reservoir/backing trilaminate. Finally, this laminate is die-cut to produce individual systems. Bisoprolol patches with thinner reservoirs could also be made, e.g., with reservoirs of 1-lOmil thickness.

EXAMPLE 5

Transdermal Gel Reservoir

[000101] A gel formulation of bisoprolol employed as a reservoir system and used for in vitro skin permeation experiments was prepared as described below. According to the constituents of the reservoir listed in Table 1 above, 1.2 g of bisoprolol was weighed and dissolved in 3.6 g of ethanol. To it 20.5 g water was added and was mixed in a mixing roller overnight. Then 0.48 g of hydroxyl ethyl cellulose (HEC) was added and mixed for about Ih to ensure gelling.

[000102] Skin permeation studies were performed with the isolated epidermal layer of human cadaver used to quantitatively determine the permeation of bisoprolol. Skin from the abdomen was used. Full thickness, non-hairy, human skin was cleaned of all fat and extraneous materials. The skin was then rinsed and placed into a beaker with distilled water first at 35⁰C for 5 minutes, then at 61⁰C for 1 minute. The epidermis was carefully separated from the dermis and inspected for holes. Discs of epidermis were die-cut using a 1 ³A₆ inch diameter arch punch. The epidermis was then stored stratum corneum side up, and kept hydrated at 4°C before use, typically the next day. 0.05 M KH₂PO4/KHPO₄ buffer, pH 6.5 with 1% cyclodextrin was used as the receptor medium. Medium (diffusion area: 1.98 cm²) vertical Franz diffusion cells were used. For each cell, a disc of epidermis (size 1 /₁₆ inch=3cm) was placed on the receptor compartment. In one set, the gel formulation of bisoprolol was directly added on top of the skin while in another set, a disc (³/4 inch=1.9cm) of EVA28 (rate-control membrane) laminated on silicone adhesive was placed on top of the skin and the gel added on the EVA28 side. The first set was a simulation of a reservoir containing a gel with a micorporous membrane and the second set was a reservoir with a rate-control membrane. A microporous membrane will not have any significant effect on the flux of the drug through the skin. At time zero, the receptor solution (between 21 and 23 ml) was added into the receptor compartment and the cell was placed in a shaking water bath set at 35⁰C. This temperature yielded a skin surface temperature of 30-32⁰C. For each skin type 10 replicates were used. Receptors were sampled at 6, 24, 36, 48 and 72 hours from the start of the experiment (full volume of receptor solution was taken out and replenished with fresh buffer). The aliquoted receptor solution was assayed by HPLC at each time point.

[000103] FIG. 7 shows the bisoprolol flux in biosoprolol base equivalent. The upper curve (line with small square-like data points) represents the flux for the gel on skin delivery, and the lower curve (line with long rectangular data points) represents the flux of delivery with gel on EVA28 and silicone adhesive. The vertical lines with bars at the ends are standard deviation values. The average flux of bisoprolol at steady state through the skin using an aqueous gel directly in contact with skin was 86mcg/(cm².h). The average flux of bisoprolol at steady state through the same skin using an aqueous gel on EVA28 as a rate-control membrane and silicone adhesive was 45mcg/(cm².h). The average flux of bisoprolol shows that unlike prior reports that bisoprolol does not permeate through skin in therapeutically effective amounts, the gel formulation prepared in this example was capable of permeating at rates that delivered a therapeutically effective amount of bisoprolol from a reasonably sized patch, e.g., 4 cm² to 40 cm² in planar area. Thus, the invention provides a system and method to treat hypertension or provide prophylaxis of migraine by transdermal bisoprolol delivery.

[000104] The stability of the bisoprolol gel formulation was monitored over extended periods of time (up to a month). Table 4 lists the bisoprolol content in % at room temperature and 4O⁰C from gel formulations of bisoprolol in 70/30 water/ethanol over time, thus showing the decrease in bisoprolol with time. The data of Table 4 show that the bisoprolol was quite stable in the gel formulation.

Table 4

RT= Room temperature

EXAMPLE 6

Comparing Transdermal Multilaminate Systems

[000105] A laboratory internal mixer, such as Brabender mixer with sigma blades, was set to 4O⁰C and 5.76 g of EVA40 was slowly dispensed into the mixer starting as soon as the mixer reaches 35⁰C and the addition continued until 4O⁰C was reached. The sample was mixed at 4O⁰C and 11.4 rpm for 5 minutes. When EVA40 showed melt characteristic, 0.23 g of bisoprolol was added in small quantities and the sample mixed at 4O⁰C and 11.5 rpm for 25 minutes. Once well mixed, the sample was allowed to cool to room temperature. The sample was taken out of the mixer, weighed and placed on a release liner (3mil = 0.075mm thick siliconized PET release liner, S 3MIL CL PET 4400B/000, from Loparex) and covered with another piece of release liner. A heat press was set to 45⁰C. The sample with the release liners was placed in a typical lab hydraulic hot press and compressed for a dwell time of 30 seconds at 4O⁰C, 5000psi (3.4 x 10⁷Pa). The sample was allowed to cool on counter top. The resultant bisoprolol/EVA reservoir layer thickness was about 5mils (0.125mm.). The release liner on one side was taken off and laminated to a 2mil thick adhesive layer. The release liner on the other side was then taken off and replaced with a backing layer, such as 3M SCOTCHPAK 9732 backing film, which is comprised of 1.5mils EVA12 bonded to a 0.5mil PET film. Two different multilaminate systems were made, one with a polyacrylate adhesive (such as 1 to 3 mil thick DURO-TAK 87-4287 adhesive from National Starch & Chemical) as the in-line contacting skin layer and one with a silicone adhesive (such as 1 to 3 mil thick BIO PSA 7-4502 adhesive from Dow Corning) as the in-line skin-contacting layer. The final formulations contained 4wt% bisoprolol in the reservoir. Flux experiments were done in a similar way as the above Example.

[000106] FIG. 8 shows the in vitro flux of the two systems on cadaver skin. The curve with small square-like data points represents the bisoprolol-containing multilaminate with silicone adhesive. The curve with long rectangular data points represents the bisoprolol-containing multilaminate with polyacrylate adhesive. The vertical lines with bars at the ends are standard deviation values. The average flux of bisoprolol through the skin using either of the multilaminate systems was 3.6 mcg/(cm².h) during the 24h-72h period. The average flux of bisoprolol obtained was calculated to result in a therapeutically effective amount of bisoprolol delivered from a reasonably sized patch, e.g., 4 cm² to 40 cm² in planar area. Thus, the invention provides a system and method to treat hypertension or migraine by transdermal bisoprolol delivery. EXAMPLE 7

Transdermal Polyacrylate Matrix System

[000107] An amount of 0.4g of bisoprolol is added to 1.2g of polyacrylate adhesive (National Starch DURO-TAK 87-4287) and mixed overnight. The formulation is cast on a 213 release liner (3mil = 0.075mm thick siliconized PET release liner, S 3MIL CL PET 4400B/000, from Loparex), air dried overnight, and further oven dried at 6O⁰C for 90 minutes and laminated with EVA laminate backing (Polyester/EVA laminate film, 3M, SCOTCHPAK 9733). Five replicates of the systems are cut using a 5/8 inch (1.6cm) diameter die cut and used for skin permeation experiments conducted with the equipment and process similar to the above Examples. The resultant bisoprolol layer is about 5mils (0.125 mm.). It is expected that the flux is adequate for delivery of a therapeutic amount of bisoprolol.

EXAMPLE 8

Transdermal Delivery of Bisoprolol Salt

[000108] A drug reservoir having 65wt% EVA40 is obtained by melt blending with 15wt% bisoprolol fumarate and 10wt % oleic acid. A 5g batch is prepared by adding EVA40 pellets slowly to a 40⁰C twin-blade mixer at 11-12 rpm. EVA addition is done over a period of 1-7 minutes, followed by additional mixing for 7-8 minutes. Bisoprolol fumarate and oleic acid (permeation enhancer) are then added slowly over a period of 10-30 minutes into EVA mixture under continuous mixing. The mixture is blended for up to 40 minutes to achieve homogeneity, before removal from the mixer. The blended material is calendared to various thicknesses of 20mil (0.5mm) or more between release-coated PET liners at a speed of 0.2fpm (6cm/m) with a roll temperature of 192°F (89°C). The drug reservoir films are then laminated between the EVA face of a PET/EVA laminate film (3M SCOTCHPAK 9733) and a lmil (0.025mm) film of EVA12 at 0.4foot /min(φm), i.e. 12cm/min, with a roll temperature of 192°F (89°C). A silicone adhesive thin film cast can be prepared by casting a solvent dispersion (such as ethyl acetate or toluene) of polydimethylsiloxane and silicate resin onto a siliconized PET release liner (REXAM, Grade 10393 S 3mil (0.075mm) CL PET Al 0/000) and dried (90 minutes at 65°C) to produce a thin film, which is laminated to a EV A9 tie- layer of the tie-layer/drug reservoir/backing trilaminate. Finally, this laminate is die-cut to produce individual systems. Bisoprolol patches with thinner reservoirs could be also be made, e.g., with reservoirs of 1-lOml thickness. Such systems can be used in transdermal flux of the bisoprolol salt.

EXAMPLE 9

Administration for Treatment of Hypertension and Prophylaxis of Migraine [000109] The treatment of hypertension by administering bisoprolol in a transdermal reservoir delivery system is demonstrated in an animal model employing spontaneously hypertensive rats. In spontaneously hypertensive rats, bisoprolol administered transdermally at doses equivalent to rates shown to be efficacious by oral administration of bisoprolol, is expected to reduce both systolic blood pressure and heart rate for 24 hr during transdermal administration. It is expected that the hypotensive effects last for a period of time following the patching of bisoprolol on the back of the animals. The systolic blood pressure and heart rate following transdermal bisoprolol administrations are correlated with the time courses of the plasma bisoprolol concentration. The present findings demonstrate that administration of bisoprolol in a reservoir achieve blood pressure control over extended periods of time and demonstrates the usefulness of this bisoprolol reservoir system in treatment of hypertension.

[000110] Prophylaxis of migraine is demonstrated by administration of bisoprolol transdermally to human by comparing the incidents of migraine with transdermal bisoprolol administration and without bisoprolol administration. Since biosoprolol base is administered transdermally at a rate equal to oral doses adequate for prophylasix of migraine, it is expected that bisoprolol administered transdermally results in prophylaxis of migraine.

EXAMPLE 10 Irritation Testing

[000111] A total of 18 hairless female guinea pigs were used in the study. Each hairless guinea pig (HGP) had 4 sites of application and the formulations were randomized such that each HGP had similar total amounts of bisoprolol applied on them. Six 1.6cm² patches of bisoprolol in EVA40 reservoir with polyacrylate body- contacting adhesive (National Starch DURO-TAK^® 87-4287) similar to that shown in FIG. 2 per formulations of Table 5B below were placed on intact dorsal skin of the HGP for 24 hours. Both DURO-TAK^® 87-4287 adhesive and EVA have been shown to be non-irritating in the past and thus varying the bisoprolol content would show the irritation effect of the bisoprolol on skin. (For example, DURO-TAK^® 87-4287 adhesive is used in commercially available analgesic matrix fentanyl patches and EVA is used in commercially available smoke cessation patches.) The systems were removed after 24-hour exposure time; edema (redness) and erythema (skin swelling) readings were taken at 0.5, 24 and 48 hours and 7 days following the removal of the systems. Results of irritation study are reported as Primary Irritation Index (PII) after 1- day of patch wear and were determined by calculating the mean of the 0.5-hour and 48- hour scores of both edema and erythema. The PII categorization is as follows:

[000112] Several (multilaminate) patch formulations with different bisoprolol contents were tested for primary skin irritation in HGPs. All the formulations tested were multilaminates, consisting of bisoprolol free base in EVA 40 reservoir laminated on a 21.5 mil Durotak 87-4287. A siliconized PET release liner (3mil = 0.075mm thick siliconized PET release liner, S 3MIL CL PET 4400B/000, from Loparex) was attached to the adhesive. A layer of backing material with EVA on one surface (Polyester/EVA laminate film, 3M, SCOTCHPAK 9733) was adhered to the EVA side of the multilaminate. Table 5 A below shows the thickness of the formulations that were used for the study. Such thick bisoprolol reservoirs were used to ensure the presence of much more than sufficient drug for 7-day test for skin reaction. For flux, thinner reservoirs can be used. Table 5A

[000113] Table 5B below lists the PII for individual formulation after 1 day and 7 days of wear. All the formulations had acceptable primary irritation indices (PII). Additionally a dose response to PII was also observed. FIG. 9 shows a plot of PII in hairless guinea pig vs. in vitro flux through human cadaver skin for the same formulations shown in Table 5B. It is evident from FIG. 9 that low irritation could be achieved by using rate-control to keep the flux in the target range. From the data of FIG. 9 and Table 5B, to have minimized irritation, in some embodiments of the device for transdermal delivery, it is preferred that the flux be less than about 35mcg/(cm²h), preferably about 3mcg/(cm²h) to 35mcg/(cm²h), more preferably about 3mcg/(cm²h) to 20mcg/(cm²h). Although patches with higher bisoprolol content were not tested, patches in which the reservoir had bisoprolol content about 25wt% or less had acceptable irritation indices. Table 5B

EXAMPLE 11

Skin sensitization Testing: Local Lymph Node Assay (LLNA)

[000114] The purpose of this study was to determine whether treatment of female CBA/J mice with bisoprolol base would induce a hypersensitivity response as measured by the proliferation of lymphocytes in the draining lymph nodes. The test article was applied to the ears of three mice at concentrations of 2.5wt%, 5wt%, and 10wt% in dimethyl sulfoxide (DMSO). Mice were treated with the test article on the dorsal surface of both ears (25μl/ear), once per day for three consecutive days, using a micropipette. Five female CBA/J mice were treated per test article on the dorsal surface of both ears once per day for 3 days with bisoprolol in a DMSO vehicle (at concentrations of 2.5wt%, 5wt% and 10wt%) or with a positive control hexyl cinnamaldehyde (HCA). On day 6, the mice were injected, i.v. with 20μCi of H- thymidine in sterile saline. Five hours later, the mice were euthanized and the draining auricular lymph nodes were removed from each animal. The lymph node cells were precipitated with 5% tricholoroacetic acid (TCA) and the pellets counted in a β- scintillation counter to determine the incorporation of ³H-thymidine. A test article is considered to have skin sensitization if at one or more concentrations, it induces a threefold increase in ³H-thymidine incorporation (proliferative activity) in the lymph nodes as compared to the concurrent vehicle control animals. Table 6 shows the data from measurement of ear swelling and proliferation due to hypersensitivity respectively. In Table 6, a test/control ratio of 3.0 or greater represents a positive result of sensitization potential. A + symbol in the Result column means there is sensitization potential and a - symbol means the lack of sensitization potential. In Table 6, DPM is disintegrations per minute, which is a measure of radioactive decay; std div is the standard deviation. Thus, the results showed that treatment of the mice with bisoprolol base at 2.5wt%, 5wt% and 10wt% resulted in stimulation indices of ≤3.0 and hence are not considered to have skin sensitization potential as determined by Local Lymph Node Assay (LLNA).

Table 6

DMSO= dimethyl sulfoxide, HCA = hexyl cinnamaldehyde

[000115] In the above, when a material is said to be made of a particular chemical entity, it is meant that unless specified otherwise, it is contemplated that the particular chemical entity can constitute more in the material than any other chemical entity of a similar nature, or it can constitute the majority, or substantially all, and even all as compared to chemical entities of a similar nature in the material. For example, when it is stated that a drug reservoir is made of polyacrylate adhesive, it is meant that unless specified otherwise it is contemplated that most of the adhesive in the reservoir, substantially all of the adhesive, and even all the adhesive in the drug reservoir can be polyacrylate. When we describe a substance (C) including certain ingredients (A and B), it is contemplated that the substance (C) can also comprise, consist essentially of or consist of the certain ingredients (A and B) unless indicated to be otherwise in the present disclosure. The entire disclosure of each patent, patent application, and publication cited or described in this document is hereby incorporated herein by reference. The practice of the present invention will employ, unless otherwise indicated, conventional methods used by those in pharmaceutical product development within those of skill of the art. Embodiments of the present invention have been described with specificity. The embodiments are intended to be illustrative in all respects, rather than restrictive, of the present invention. It is to be understood that various combinations and permutations of various constituents, parts and components of the schemes disclosed herein can be implemented by one skilled in the art without departing from the scope of the present invention.

Claims

What is claimed is:

1. A transdermal patch for administering bisoprolol to a user, comprising:

(a) backing layer; and

(b) reservoir disposed proximally relative to the backing layer, said reservoir comprising a polymeric composition containing an amount of bisoprolol free base sufficient for multiple-day delivery.

2. The transdermal patch of claim 1 further comprising an in-line rate- control adhesive and the reservoir include a main matrix polymer which is selected from the group consisting of ethylene/vinyl acetate copolymer (EVA), non-acidic polyacrylate, and hydrogel polymer.

3. The transdermal patch of any of claims 1 to 2 wherein the patch size is from 4cm² to 40cm² and the rate-control in-line adhesive is one of polyisobutylene (PIB), silicone, and polyacrylate that controls the delivery rate of bisoprolol at 4 to 12mg per day.

4. The transdermal patch of any of claims 1 to 3 wherein the bisoprolol free base is dissolved or dispersed in a hot melt adhesive in the reservoir.

5. The transdermal patch of any of claims 1 to 4 wherein the reservoir includes 15wt% or less of permeation enhancer.

6. The transdermal patch of any of claims 1 to 5 wherein the reservoir includes less than 9wt% permeation enhancer.

7. The transdermal patch of any of claims 1 to 6 wherein the reservoir has less than 5wt% permeation enhancer.

8. The transdermal patch of any of claims 1 to 7 wherein the bisoprolol free base is dissolved or dispersed in a hot melt of EVA in the reservoir, the device having an in-line rate-control adhesive of PIB.

9. The transdermal patch of any of claims 1 to 8 comprising a rate-control in-line adhesive different from the main matrix polymer, and the patch further comprising an EVA tie layer disposed between the reservoir and the in-line adhesive.

10. The transdermal patch of any of claims 1 to 9 wherein the backing layer has EVA content within 5wt% of that of the tie layer, the backing and tie layer EVA having lower vinyl acetate content than EVA in the reservoir, the reservoir EVA having more than 20wt% of vinyl acetate.

11. The transdermal patch of any of claims 1 to 9 wherein the backing layer is a polyethylene theraphthalate poly(ethylene-co-vinyl acetate) (PET/EVA) laminate with the EVA facing the reservoir, the EVA in the backing having 20wt% or less of vinyl acetate content and the tile layer EVA having 20wt% or less of vinyl acetate content, the reservoir having EVA containing more than 20wt% of vinyl acetate.

12. The transdermal patch of any of claims 1 to 9 wherein the reservoir contains EVA with more than 20wt% of vinyl acetate content and the in-line rate- control adhesive is PIB.

13. The transdermal patch of any of claims 1 to 9 wherein the reservoir contains EVA with 35wt% or more of vinyl acetate content.

14. The transdermal patch of any of claims 1 to 13 wherein the reservoir contains bisoprolol free base adequate for delivery for 3 days or more.

15. The transdermal patch of any of claims 1 to 14 wherein the reservoir contains bisoprolol free base adequate for delivery for up to 9 days.

16. The transdermal patch of any of claims 1 to 9 wherein the reservoir contains at least 20wt% bisoprolol free base and at least 60wt% EVA.

17. The transdermal patch of any of claims 1 to 16 wherein the reservoir is substantially free of an adhesive polymer with acidic functionality.

18. The transdermal patch of any of claims 1 to 17 wherein the device has an average bisoprolol flux of 5mcg/(cm².h) or more for 1 day or more.

19. The transdermal patch of any of claims 1 to 9 wherein the reservoir contains bisoprolol free base adequate for delivery for 3 days or more with an average flux of a flux of 5mcg/(cm².h) or more.

20. The transdermal patch of any of claims 1 to 19 further comprising an adhesive overlay disposed distal to the backing layer and a protective liner disposed proximal to the in-line rate-control adhesive.

21. The transdermal patch of any of claims 1 to 7 wherein the rate-control adhesive is silicone adhesive.

22. The transdermal patch of any of claims 1 to 21 wherein the rate-control adhesive contains 4wt% or less of an alkaline salt of an organic acid.

23. A method for making a transdermal patch for administering a bisoprolol to a user, comprising:

(a) disposing a reservoir proximally relative to a backing layer; and

(b) forming the reservoir, which contains a polymeric composition containing an amount of bisoprolol free base sufficient for multiple-day delivery.

24. The method of claim 23 comprising including an in-line rate-control adhesive more proximal to the user's body surface relative to the reservoir.

25. The method of any of claims 23 to 24 comprising using a patch size from 4 cm² to 40 cm² including polyisobutylene (PIB) as the in-line rate-control adhesive such that the PIB controls the delivery rate of bisoprolol free base at 4 to 12mg per day.

26. The method of any of claims 23 to 25 comprising dissolving or dispersing the bisoprolol free base in a hot melt of poly(ethylene-co-vinyl acetate) (EVA) for the reservoir, further comprising disposing a tie layer between the reservoir and in-line rate-control adhesive.

27. The method of any of claims 23 to 26 comprising dissolving or dispersing the bisoprolol free base in a hot melt of EVA for the reservoir, wherein the backing layer contains EVA, further comprising disposing an EVA tie layer between the reservoir and the in-line rate-control adhesive, which includes PIB.

28. The method of any of claims 26 to 27 wherein the backing layer has EVA and the tie layer EVA and the backing layer EVA both have lower vinyl acetate content than the EVA in the reservoir.

29. The method of any of claims 26 to 28 wherein the backing layer has EVA and the tie layer EVA and the backing layer EVA both have lower vinyl acetate content than the EVA in the reservoir, the reservoir EVA having at least 35wt% vinyl acetate.

30. The method of any of claims 23 to 29 comprising including bisoprolol free base in the reservoir adequate for delivery for up to 7 days.

31. The method of claims 23 to 30 comprising including in the reservoir at least 20wt% bisoprolol free base and at least 60wt% EVA.

32. The transdermal patch of claims 23 to 31 wherein the reservoir is substantially free of an adhesive polymer with acid functionality.

32. Use of bisoprolol free base in the preparation of a transdermal delivery patch for the treatment of hypertension or prophylaxis of migraine, wherein the transdermal delivery patch comprising:

(a) backing layer; and