EP2262368A1 - Dicyclanil formulation - Google Patents

Abstract

Described are concentrates consisting of solutions of dicyclanil (DCL) in polyethylene glycol (PEG), their preparation and their use for the preparation of low-dose aqueous DCL-PEG solutions for combating insects, such as blowfly on sheep and goats or for combating insects such as Musca spp. in the environmental hygiene area. It also relates to the DCL- PEG concentrates as such and dicyclanil solutions and the low-dose ready-to-use aqueous DCL-PEG solutions as such. Embraced are also combinations with other suitable parasiticides or insecticides.

Description

DICYCLANIL FORMULATION

The present invention relates to concentrates consisting of solutions of dicyclanil (DCL) in polyethylene glycol (PEG), their preparation and their use for the preparation of low-dose aqueous DCL-PEG solutions for combating insects, such as blowfly on sheep and goats or for combating insects in the environmental hygiene area. It also relates to the DCL-PEG concentrates as such and dicyclanil solutions and the low-dose aqueous DCL-PEG solutions as such.

Field of the invention

Over the last two decades the pharmaceutical industry has focused on the development of very long lasting (persistent) veterinary medicines for domestic (farm) and companion animals. The general assumption was that the products must exhibit full efficacy over a period of weeks or even months in order to be well accepted by the veterinarians and end user customers. One thought that extremely long lasting efficacy would be the key for commercial success. For some products this became true; however others failed because one had missed that long lasting efficacy would most often go hand in hand with undesired side effects.

This invention deals with a product that closely relates to a commercially important threat, especially for sheep farmers. Blowfly strike (myiasis) in sheep and to a certain extent in goats is a significant animal welfare issue resulting in an horrendous disease that can cause loss of productivity and death in sheep. Fly strike in sheep is caused by a number of blowfly species (e.g. Lucilia sericata, Lucilia cuprina, Calliphora stygia, Calliphora augur, Chrysomyia rufifacies). The adult fly lays eggs on the live sheep, which subsequently hatch to larval stages that feed on the flesh of the live sheep. These larvae are very active and secrete enzymes which liquefy the skin and flesh of the sheep upon which they are feeding. Once their development is complete on the host, the mature larvae fall off the fleece and pupate in the soil. In favorable weather conditions (i.e. temperatures exceeding 14°C and relatively high humidity) blowfly populations attacking sheep flocks can 'explode within a week once the first flies have emerged from the soil'. FIy strike may occur on any part of the body where the fleece has become soiled or infected with bacteria. Sheep are commonly struck on the breech region where the wool becomes soiled by feces and urine or on the back, where the hollow in the shoulders provides an ideal environment for moisture to be held and bacterial growth to occur. Castration and tail docking wounds, mulesing wounds, shearing wounds, head wounds on fighting rams and any other open wound will attract strike flies ('wound' strike), particularly if the wound becomes infected with bacteria. The smell of foot-rot is also particularly attractive to blowflies and in many cases the fleece over the chest wall becomes contaminated from the infected foot when the sheep lies down and thus provides another site for fly strike to occur.

Fly strike is a severe animal welfare problem and animals suffering from the disease show obvious signs of distress. They become distracted, spending less time grazing and more time rubbing and/or biting the 'struck' areas of their bodies. If the disease goes untreated and secondary strike occurs, the wounds can become very extensive and bacterial infection may lead to serious complications and death from septicemia and toxemia. On examination of the struck area there are often large areas of decaying gangrenous flesh accompanied by an associated putrid smell and visible signs of maggot activity.

Prevention of blowfly strike can be achieved by applying insecticidal or insect growth regulating (IGR) chemicals to the sheep by traditional dipping, back-lining ('pour-on' or 'spray-on'), hand-jetting or jetting race applications. The insecticidal treatments kill maggots that are already active on the sheep and in some cases provide limited (several weeks) and often variable protection against re-strike. The period of protection provided will vary between insecticide and specific fly strain. However, most insecticidal chemicals used in this area are considered 'toxic', e.g. organophosphates and they disadvantage the farmers with long withholding (35+days) periods where the sheep have to be retained 'on-farm' before they can be sold for slaughter (for human consumption) or be shorn for wool production.

Preventative applications of the IGR chemicals have the significant advantage of preventing fly strike by interrupting the larval development cycle as the maggots molt between instars, thus arresting the development of maggots before they mature to the critical pathological late instar stages that cause the serious damage to their host. Prevention of fly strike is far preferable to curative treatment. It is more welfare friendly to the sheep than waiting for signs of strike to appear as often a high percentage of a flock can be struck within a short time period (e.g. several days) during a high pressure 'fly wave'. Prevention is also far preferable to the sheep producer because it allows them the opportunity to integrate a responsible, preventative program into their overall farm management system thereby minimizing economic losses as well as increasing the welfare conditions for their livestock. The dominant products currently on the market are applied as back-liners or as jet sprays (using a variety of equipment designs and methods) although 'saturation' dipping is still popular in some countries.

The most effective chemical compound used in the control of blowfly strike is dicyclanil (DCL), (4,6-diamino-2-cyclopropylaminopyrimidine-5-carbonitrile). DCL is described in US- 4,783,468. It is commercially available under the trade name CLiK^® Spray-On (or CLiK^® Pour-On). CLiK^® is a ready-to-use spray-on/pour-on concentrated aqueous suspoemulsion formulation containing as active ingredient 50 g DCL per liter (5%). When applied at this concentration, CLiK^® confers up to 24 weeks protection against fly strike dependent on the intensity of the infestation ('fly pressure'), the prevailing climatic conditions (encompassing geographic location) and sheep breed type. However, the down side is that the meat of sheep that have been treated with DCL 5% must not be used for human consumption for extended periods, for example, 56 days in New Zealand, 28 days in Australia and 40 days in the European Union. Additionally, the wool must not be shorn from treated sheep, for subsequent use in clothing and textiles, for 2 or 3 months after application to New Zealand and Australian sheep flocks, respectively. These restrictions significantly hinder sheep producers and in some circumstances may lead them to chance no preventative cover of their sheep despite the risk of fly strike hitting their flocks.

The majority of Merino sheep farmers in Australia, New Zealand and South Africa have, since the early 1930s, used the practice of 'mulesing' to prevent or reduce the incidence of blowfly strike on the breeches of their sheep. Mulesing is the surgical removal (without the use of anesthetics) of strips of wool-bearing skin from around the breech of the sheep. Mulesing is still a common practice in Australia (where most Merino sheep are found) but it is expected to be phased out by year 2010. Current sheep industry opinion considers the practice to be a necessary compromise in providing for the general welfare of sheep in fly strike prone geographic regions. However, animal welfare groups strongly object to this procedure and the welfare concerns are partially responsible for its planned phase out. - A -

However no single alternative to mulesing has yet been proven, although sheep farmers who have ceased the practice, often resort to DCL 5% as a substitute treatment.

Thus, as a matter of fact, persistent products require extremely potent active ingredients, administered to animals at high concentrations, and which in the ideal case are manageable without causing problems. However, as demonstrated with DCL, most often such chemical compounds exhibit not only the desired activity but also undesirable side effects. These side effects are eventually problematic thereby diminishing commercial success. In the case of blowfly control, the industry has in the past perhaps been too focused on the long duration of efficacy and in doing so, might have underestimated problems that relate to chemical residues. On the other hand, sheep consumers and regulatory authorities are very interested in having meat and wool products that are free of pesticides.

Therefore, there is a clear need for tailor-made products that provide sufficient efficacy but avoid possible residue problems in meat and wool.

Summary and detailed description of the invention

It has now surprisingly been found that with said DCL one can develop a formulation that still exhibits sufficient activity against various insects including blowfly but reduces the discussed residue problems in wool and meat to a minimum. It is even more surprising that this can be achieved by a very simple technical means.

As described above, the commercial product CLiK^® Spray-on is formulated as an aqueous suspoemulsion because the active ingredient DCL is poorly soluble in water and most other physiologically acceptable solvents. The concentration of a saturated aqueous solution of DCL at room temperature is only about 300 ppm. DCL, when exposed to an aqueous environment has a high tendency to precipitate, which is very disadvantageous for the development of a water-based commercial product. This is why many previous attempts to produce a stable liquid formulation that could be safely stored for months or years have failed. To overcome the solubility problem and nevertheless end up with a formulation that is highly loaded with the active ingredient necessary to achieve a long lasting efficacy, the inventors of CLiK^® developed an aqueous emulsion wherein the DCL was suspended in a microcrystalline form. By adding dispersion agents the inventors managed to develop the highly concentrated and very effective CLiK^® spray-on/pour-on formulation. However, despite its effectiveness, the product still has the meat and wool residue problems discussed above.

The inventors of the present invention now identified that PEG is the ideal solvent for DCL. Polyethylene glycol (PEG) is HO-(CH₂CH₂O)_n-H and is available in a variety of molecular weights from 200 to tens of thousands. The melting points of PEGs vary depending on the Formula Weight of the polymer. PEG has the following structure: HO-(CH2-CH2-O-)n-H The numbers that are often included in the names of PEGs indicate their average molecular weights, e.g. a PEG with n=80 would have an average molecular weight of approximately 3500 daltons and would be labeled PEG 3500. Most PEGs include molecules with a distribution of molecular weights, i.e. they are polydisperse. The size distribution can be characterized statistically by its weight average molecular weight (Mw) and its number average molecular weight (Mn), the ratio of which is called the polydispersity index (Mw/Mn). Mw and Mn can be measured by mass spectroscopy. At room temperature, the water soluble and hygroscopic polymer is a colorless viscous liquid at molecular weight below 600 and a waxy, white solid at molecular weights above 800, i.e. the higher the molecular weight, the more solid is the PEG. The numerical designation of PEGs generally indicates the number average molecular weight (e.g. PEG-2000), although typically they are not monodisperse polymers. Liquid PEG is miscible with water in all proportions and solid PEG is highly soluble in water, for example, PEG-2000 has a solubility of about 60% in water at 20⁰C.

PEG has a number of benign characteristics that underlie, for example, its application in bioseparations. PEG is on the United States Food and Drug Administration's (FDA) GRAS list (compounds Generally Recognized as Safe) and has been approved by this authority for internal consumption. PEG is weakly, if at all, immunogenic, a factor which has enabled the development of PEG-protein conjugates as drugs. Aqueous solutions of PEG are biocompatible and are utilized in tissue culture media and for organ preservation. Low molecular weight liquid PEGs are non-volatile. The vapor density for low molecular weight PEG is greater than 1 relative to air according to available MSDS data. PEG also has low flammability and is biodegradable. PEG has been found to be stable to acid, base, high temperature, H₂O₂ high oxidation systems and NaBH₄ reduction systems, although partial oxidation of the PEG terminal -CH₂OH group to -COOH may occur in such systems as H₂θ₂-Na₂WC>₄. In addition, PEG may be recovered from aqueous solution by extraction with a suitable solvent or by direct distillation of water or solvent.

In context with the present invention low molecular weight PEG is PEG with a molecular weight between 200 and 600, medium molecular weight PEG is PEG with a molecular weight between 600 and 1500, and high molecular weight PEG is PEF with a molecular weight between 1500 to about 8000. The use of low molecular weight PEG leads to liquid formulations. The use of medium molecular weight PEG leads to semi-liquid, i.e. waxes or paste-like formulations, and the use of high molecular weight PEG leads to relatively solid formulations, which can form powders, coarse-grained powders or granules.

Thus, the current inventors found that solutions or dispersions of DCL in PEG of different molecular weight lead to interesting and commercially valuable products that can have very desirable properties. For example, the use of low molecular PEG leads to liquid solutions, whereas PEG with high molecular weight, if it is highly loaded with DCL, results in waxy or even solid products consisting of a dispersion of DCL in PEG. Depending on the molecular weight one can develop liquid solutions, pastes, waxes and even solid granules. Liquid and solid PEGs can be used as solvents for DCL without addition of water. They are especially suitable for the production of water-free PEG solutions/dispersions with a high concentration of DCL. In context with the present invention they are called 'DCL-PEG concentrates'. These DCL-PEG concentrates are basically free of water, i.e. that the PEG is commercially available PEG to which no water has been added. Before these DCL-PEG concentrates can be used on animals or in the hygiene area, they have to be diluted with the appropriate amount of water to form the 'ready-for-use' aqueous DCL-PEG solution, provided the concentration of DCL does not exceed 2.5%. DCL dissolved in PEG is extremely stable. It forms a real solution and does not precipitate. The solution can be stored for years.

Low molecular weight DCL-PEG concentrates contain 3% to 6%, preferably about 5% DCL dissolved in low molecular weight PEG. Medium molecular weight DCL-PEG concentrates contain 3% to 5%, preferably about 5% DCL dissolved in medium molecular weight PEG, and high molecular weight DCL-PEG concentrates contain 5% to 20% or even more DCL dispersed in high molecular weight PEG. Percentages, if not otherwise specified are given as weight : weight (w/w) percentages. An appropriate amount of each of these DCL-PEG concentrates can be easily dissolved in the appropriate volume of water to result in an aqueous ready-to-use DCL-PEG solution.

Said DCL-PEG concentrates, which are not 'ready-to-use' formulations, are extremely suitable as new commercial forms of DCL. DCL-PEG concentrates have many advantages over the current commercial 5% CLiK^® spray-on/pour-on formulation. Even if they contain fairly high amounts of the active ingredient, they can be stored over months and years and the DCL is not degraded. Moreover they remain as real solutions, wherein no precipitation occurs. In contrast to the 'ready-to-use' aqueous CLiK^® spray-on/pour-on formulation, these concentrates can be stored in small 'dose equivalent' containers under a wide variety of conditions and over a long period of time without any special precautions. Thus, transportation, packaging and storage is much simpler and less expensive.

With these DCL-PEG concentrates the end-user can easily prepare 'ready-to-use' aqueous solutions of desired strength, which is not possible with the CLiK^® spray-on/pour-on formulation. However, the comparison to the commercial CLiK^® spray-on/pour-on formulation with real aqueous low concentration solutions of DCL (prepared from the concentrate formulation) surprisingly brings a number of significant advantages to sheep producers:

^■ When applied as a 'jetting fluid' via appropriate jetting application equipment, a uniform penetration of the sheep's fleece with DCL will be achieved to enhance the duration and reliability of biological effect, with a reduced quantity of active ingredient.

^■ When applied as a solution spray-on or pour-on (of defined concentration), an even application of DCL over the 'at risk' areas of the sheep will achieve a desired period of protection (on the basis of the defined concentration); thus less active ingredient will be required. For example, reducing the concentration of active ingredient to only 25% of that in the CLiK^® spray-on/pour-on formulation only reduces the protection period to approximately 50% of that conferred by the more concentrated product.

^■ A reduction in the quantity of active ingredient used to achieve the desired period of protection will reduce the subsequent withholding periods for consumption of meat and/or (wool) shearing. This offers a breakthrough to the sheep producer, allowing the best commercially available active ingredient and prophylactic currently available for the control of blowfly strike to be used but with reduced trade withholding penalties.

^■ A solution applied as a jet spray or as a spray-on (or pour-on), which is able to penetrate the breech wool in a way that protects the sheep against blowfly strike, would replace the need for farmers to mules their (Merino) sheep and provide the sheep industry with a much required answer to the planned withdrawal of the mulesing practice by 2010.

^■ A low concentration solution that can be used at targeted sites of application (e.g wounds arising from tail docking and/or castration) more effectively with a reduced amount of DCL applied to the specific area would provide protection against fly strike to the specific area but with a much reduced trade withholding time for the sheep. This would give more flexibility to the farmer in the management of his/her flock against blowfly strike.

^■ A low concentration solution delivers protection against blowfly strike but, as less active ingredient is used, the risks of environmental and animal toxicity are reduced.

^■ A low concentration of DCL delivered as a solution formulation provides a farmer desired profile of medium-term protection against fly strike with an accompanying reduction in withholding times, increased safety to the animal and user and flexibility in application in a sheep producer friendly manner.

^■ And last not least, a real solution of DCL can be used in the environmental hygiene area against undesired insects, for example, flies. For this purpose the solution can be sprayed on to effluent waste, or livestock feedlots or bedding in animal stables.

The current inventors found out that the ideal aqueous 'ready-to-use' low-dose solution contains about 1.25% by weight of DCL, which is only one quarter of the active ingredient of the commercial CLiK^® spray-on/pour-on suspoemulsion.

The beauty of the PEG formulation according to the present invention is that it can contain the DCL either as the sole active ingredient or in order to achieve additional biological effects it can be combined with other biocides. DCL may actually be combined with pesticides having the same sphere of activity e.g. to increase activity, or with substances having another sphere of activity e.g. to broaden the range of activity. It can also be sensible to add so-called repellents. By combining DCL with other suitable parasiticides, not only the parasiticidal activity can be enhanced but the greatest part of those parasites that cause significant economic damage will be covered. Moreover, this action will contribute substantially to avoiding the formation of drug resistance. Many combinations may also lead to synergistic effects, i.e. the total amount of active ingredient can be reduced, which is desirable from an ecological point of view. Preferred groups of combination partners and especially preferred combination partners are named in the following, whereby combinations may contain one or more of these partners in addition to DCL.

Suitable partners in the mixture may be biocides, e.g. the insecticides and acaricides with a varying mechanism of activity, which are named in the following and have been known to the person skilled in the art for a long time, e.g. chitin synthesis inhibitors, growth regulators; active ingredients which act as juvenile hormones; active ingredients which act as adulticides; broad-band insecticides, broad-band acaricides and nematocides; and also the well known anthelmintics and insect- and/or acarid-deterring substances, said repellents or detachers. Non-limitative examples of suitable insecticides and acaricides are:

1. Abamectin 96. Dioxathion 191. Omethoate

2. Acephate 97. Disulfoton 192. Oxamyl

3. Acequinocyl 98. DNOC 193. Oxydemethon M

4. Acetamiprid 99. Doramectin 194. Oxydeprofos

5. Acetoprole 100. DPX-HGW86 195. Parathion

6. Acrinathrin 101. Edifenphos 196. Parathion-methyl

7. AKD-1022 102. Emamectin 197. Permethrin

8. Alanycarb 103. Empenthrin 198. Phenothrin

9. Aldicarb 104. Endosulfan 199. Phenthoate

10. Aldoxycarb 105. Esfenvalerat 200. Phorate

1 1. Allethrin 106. Ethiofencarb 201. Phosalone

12. Alpha-cypermethrin 107. Ethion 202. Phosmet

13. Alphamethrin 108. Ethiprole 203. Phosphamidon

14. Amidoflumet 109. Ethoprophos 204. Phoxim

15. Amitraz 1 10. Etofenprox 205. Pirimicarb

16. Anabasine 1 1 1. Etoxazole 206. Pirimiphos A

17. Avermectin B1 112. Etrimphos 207. Pirimiphos M

18. Azadirachtin 1 13. Fenamiphos 208. Polynactins 19. Azamethiphos 114. Fenazaquin 209. Prallethrin

20. Azinphos-ethyl 1 15. Fenbutatin oxid 210. Profenofos

21. Azinphos-methyl 1 16. Fenitrothion 21 1. Profluthrin

22. Azocyclotin 1 17. Fenobucarb 212. Promecarb

23. Bacillus subtil, toxin 1 18. Fenothiocarb 213. Propafos

24. Bacillus thuringiensis 1 19. Fenoxycarb 214. Propargite

25. Benclothiaz 120. Fenpropathrin 215. Propoxur

26. Bendiocarb 121. Fenpyroximate 216. Prothiofos

27. Benfuracarb 122. Fenthion 217. Prothoate

28. Bensultap 123. Fenvalerate 218. Protrifenbute

29. Benzoximate 124. Fipronil 219. Pymetrozine

30. Beta-cyfluthrin 125. Flonicamid 220. Pyrachlofos

31. Beta-cypermethrin 126. Fluacrypyrim 221. Pyrafluprole

32. Bifenazate 127. Fluazinam 222. Pyresmethrin

33. Bifenthrin 128. Fluazuron 223. Pyrethrin

34. Bioallethrin 129. Flubendiamide 224. Pyrethrum

35. Bioresmethrin 130. Flucycloxuron 225. Pyridaben

36. Bistrifluron 131. Flucythrinate 226. Pyridalyl

37. BPMC 132. Flufenerim 227. Pyridaphenthion

38. Brofenprox 133. Flufenoxuron 228. Pyrifluquinazon

39. Bromophos A 134. Flufenprox 229. Pyrimidifen

40. Bromopropylate 135. Flumethrin 230. Pyriprole

41. Bufencarb 136. Fonophos 231. Pyriproxyfen

42. Buprofezin 137. Formothion 232. Quinalphos

43. Butocarboxim 138. Fosthiazate 233. Resmethrin

44. Cadusafos 139. Fubfenprox 234. Rotenone

45. Carbaryl 140. Furathiocarb 235. RU 15525

46. Carbofuran 141. Gamma-cyhalothrin 236. Sabadilla

47. Carbophenothion 142. Halfenprox 237. Salithion

48. Carbosulfan 143. Halofenozide 238. Selamectin

49. Cartap 144. HCH 239. Silafluofen

50. Chloethocarb 145. Heptenophos 240. Spinetoram

51. Chlorantraniliprole 146. Hexaflumuron 241. Spinosad 52. Chlorethoxyfos 147. Hexythiazox 242. Spirodiclofen

53. Chlorfenapyr 148. Hydramethylnon 243. Spiromesifen

54. Chlorfenvinphos 149. Hydroprene 244. Spirotetramat

55. Chlorfluazuron 150. lmidacloprid 245. Sulcofuron sodium

56. Chlormephos 151. lmiprothrin 246. Sulfluramid

57. Chlorpyrifos 152. Indoxacarb 247. Sulfotep

58. Chlorpyrifos-methyl 153. insect-active fungi 248. Sulfur

59. Chromafenozide 154. insect-active 249. Sulprofos nematodes

60. Cis-Resmethrin 155. insect-active viruses 250. Tau-fluvalinate

61. Clofentezin 156. lprobenfos 251. Tebufenozide

62. Clothianidin 157. lsofenphos 252. Tebufenpyrad

63. Coumaphos 158. lsoprocarb 253. Tebupirimfos

64. Cyanophos 159. Isoxathion 254. Teflubenzuron

65. Cycloprothrin 160. Ivermectin 255. Tefluthrin

66. Cyenopyrafen 161. Karanjin 256. Temephos

67. Cyflumetofen 162. Kinoprene 257. Terbufos

68. Cyfluthrin 163. Lamba-Cyhalothrin 258. Tetrachlorvinphos

69. Cyhalothrin 164. Lepimectin 259. Tetrad ifon

70. Cyhexatin 165. Lufenuron 260. Tetramethrin

71. Cymiazole 166. Malathion 261. Thiacloprid

72. Cypermethrin 167. Mecarbam 262. Thiamethoxam

73. Cyphenothrin 168. Mesulfenphos 263. Thiocyclam

74. Cyromazine 169. Metaflumizone 264. Thiodicarb

75. Deltamethrin 170. Metaldehyde 265. Thiofanox

76. Demeton M 171. Methamidophos 266. Thionazin

77. Demeton S 172. Methidathion 267. Thiosultap

78. Demeton-S-methyl 173. Methiocarb 268. Thuringiensin

79. Diafenthiuron 174. Methomyl 269. Tolfenpyrad

80. Diazinon 175. Methoprene 270. Tralomethrin

81. Dichlofenthion 176. Methothrin 271. Transfluthrin

82. Dichlorvos 177. Methoxyfenozide 272. Triarathene

83. Dicofol 178. Metofluthrin 273. Triazamate 84. Dicrotophos 179. Metolcarb 274. Triazophos

85. Penfluron 180. Metoxadiazone 275. Trichlorfon

86. Diethion 181. Mevinphos 276. Triflumuron

87. Diflovidazin 182. Milbemectin 277. Trimethacarb

88. Diflubenzuron 183. Milbemycin oxime 278. Vamidothion

89. Dimefluthrin 184. Monocrotophos 279. Vaniliprole

90. Dimethoate 185. Moxidectin 280. XMC (3,5,- Xylylmethylcarbamate)

91. Dimethylvinphos 186. Naled 281. Xylylcarb

92. Dinobuton 187. Nicotine 282. Zeta-cypermethrin

93. Dinocap 188. Nitenpyram 283. Zetamethrin

94. Dinotefuran 189. Novaluron 284. ZXI 8901

95. Diofenolan 190. Noviflumuron

Non-limitative examples of suitable anthelmintics are named in the following, a few representatives have anthelmintic activity in addition to the insecticidal and acaricidal activity. Some of them are already listed above.

(A1 ) Abamectin (A2) Albendazole (A3) Cambendazole

(A4) Closantel (A5) Diethylcarbamazine (A6) Doramectin

(A7) Emodepside (A8) Eprinomectin (A9) Febantel

(A10) Fendendazole (A1 1 ) Flubendazole (A12) Ivermectin

(A13) Levamisol (A14) Mebendazole (A15) Milbemectin

(A16) Milbemycin Oxime (A17) Morantel (A18) Moxidectin

(A19) Nitroscanate (A20) Omphalotin (A21 ) Oxantel

(A22) Oxfendazole (A23) Oxibendazole (A24) Phenothiazine

(A25) Piperazine (A26) PNU-97333 (A27) PNU-141962

(A28) Praziquantel (A29) Pyrantel (A30) Thiabendazole

(A31 ) Triclabendazole (A32) Monepantel

If DCL is used in combination with an anthelmintic it is advisable to add to the topical formulation a skin penetration enhancer. The skin penetration enhancers used herein include one or more of the following: N-methyl-2-pyrrolidone, 1-dodecyl-azacycloheptan-2- one, diethylene glycol monoethyl ether (Transcutol), oleic acid, oleyl alcohol, linoleic acid, isopropyl linoleate and butanediol.

Non-limitative examples of suitable repellents and detachers are: (R1 ) DEET (N, N-diethyl-m-toluamide) (R2) KBR 3023 N-butyl-2-oxycarbonyl-(2-hydroxy)-piperidine (R3) Cymiazole = N,-2,3-dihydro-3-methyl-1 ,3-thiazol-2-ylidene-2,4-xylidene

Non-limitative examples of suitable synergists are:

(51 ) Piperonyl butoxide (S4) Piprotal (S7) Sesamolin

(52) Ethylenediaminetetraacetic acid (S5) Propyl isome (S8) Sulfoxide (S2) Cyclodextrin (S6) Sesamex (S9) Tribufos

Synergists S1 to S9 are well-known or can be found on the Internet, for example, in the Compendium of Pesticide Common Names. Synergists are compounds which increase the action of the active compounds without it being necessary for the synergist added to be active itself.

The above-specified combination partners are best known to specialists in this field. Most are described in various editions of the Pesticide Manual, The British Crop Protection Council, London, and others in the various editions of The Merck Index, Merck & Co., Inc., Rahway, New Jersey, USA or in patent literature. Therefore, the following listing is restricted to a few places where they may be found by way of example.

The commercially available compounds described in the table above can be found in The Pesticide Manual, 14th Ed. (2006), The British Crop Protection Council, London except for 99, 160, 183, 185, 238, A2, A6, A8, A9, A10, A12, A13, A16, A17, A18, A22, A23, A25, A28, A29, A30, which are described in the Compendium of Veterinary Products, 9th Ed. (2006), North American Compendiums, Inc.. Compounds Nos. 5, 7, 14, 66, 67, 100, 132, 163, 218, 221 , 228, 230, 240, 244, 268, and 279 can be found on the Internet, for example, in the online Merck Veterinary Manual and Compendium of Pesticide Common Names. 154: a preparation which contains insect-active nematodes, preferably Heterorhabditis bacteήophora and Heterorhabditis megidis, from The Pesticide Manual, 1 1^th Ed. (1997), The British Crop Protection Council, London, page 671 ; Steinernema feltiae, from The Pesticide Manual, 1 1^th Ed. (1997), The British Crop Protection Council, London, page 1 115 and Steinernema scapterisci, from The Pesticide Manual, 1 1^th Ed. (1997), The British Crop

Protection Council, London, page 1 1 16;

153: a preparation which contains insect-active fungi, preferably Verticillium lecanii, from

The Pesticide Manual, 1 1^th Ed. (1997), The British Crop Protection Council, London, page

1266; Beauveria brogniartii, from The Pesticide Manual, 1 1^th Ed. (1997), The British Crop

Protection Council, London, page 85 and Beauveria bassiana, from The Pesticide Manual,

1 1^th Ed. (1997), The British Crop Protection Council, London, page 83;

155: a preparation which contains insect-active viruses, preferably Neodipridon sertifer

NPV, from The Pesticide Manual, 1 1^th Ed. (1997), The British Crop Protection Council,

London, page 1342; Mamestra brassicae NPV, from The Pesticide Manual, 1 1^th Ed. (1997),

The British Crop Protection Council, London, page 759 and Cydia pomonella granulosis vviirruuss,, ffrroomm TThhee PPeessticide Manual, 1 1^th Ed. (1997), The British Crop Protection Council, London, page 291.

Preferred is the combination of DCL with a spinosin insecticide such as spinosad or spinetoram, most preferably with spinosad (mixture of spinosin A and spinosin D); as well as the combination of DCL with a natural or synthetic pyrethroid insecticide selected from the pyrethroid ester insecticides acrinathrin; allethrin; bioallethrin; barthrin; bifenthrin; bioethanomethrin; cyclethrin; cycloprothrin; cyfluthrin; beta-cyfluthrin; cyhalothrin; gamma- cyhalothrin; lambda-cyhalothrin; cypermethrin; alpha-cypermethrin; beta-cypermethrin; theta-cypermethrin; zeta-cypermethrin; cyphenothrin; deltamethrin; dimefluthrin; dimethrin; empenthrin; fenfluthrin; fenpirithrin; fenpropathrin; fenvalerate; esfenvalerate; flucythrinate; fluvalinate; tau-fluvalinate; furethrin; imiprothrin; metofluthrin; permethrin; biopermethrin; transpermethrin; phenothrin; prallethrin; profluthrin; pyresmethrin and resmethrin; bioresmethrin; cismethrin; tefluthrin; terallethrin; tetramethrin; tralomethrin; transfluthrin; or with one of the pyrethroid ether insecticides selected from etofenprox; flufenprox; halfenprox; protrifenbute and silafluofen. The most preferred pyrethroid combination partner is lamba-cyhalothrin. The combination of DCL and lamba-cyhalothrin is especially useful in combating insects such as housefly (Musca domestica) in an hygiene environment. It results in a fast and a long lasting effect. The pyrethroids are a well-known class of insecticides that is widely described in patents and in scientific papers. As a consequence of the above details, a further essential aspect of the present invention relates to combination preparations for the control of parasites on warm-blooded animals, characterized in that they contain, in addition to DCL, at least one further active ingredient having the same or different sphere of activity and at least one physiologically acceptable carrier. The present invention is not restricted to two-fold combinations.

As a matter of fact, a combination product has not necessarily to be a physical mixture of DCL and one or more further active ingredients dissolved in PEG and diluted with water prior to its use on an animal or in the hygiene area but could also consist of separate PEG- concentrates each containing only one active ingredient that are stored in separate containers or in separate compartments of the same container and diluted with water only shortly prior to their use. Keeping the PEG-concentrates of DCL and of other active ingredients separate is especially advantageous in those cases where the further active has a negative impact, e.g. on the stability of the product. Thus, physical mixtures comprising DCL and at least one additional pesticide or parasiticide represent one aspect of the present invention, and a kit of parts comprising a DCL-PEG concentrate in one container or compartment of a container, and at least a further PEG-concentrate containing a different pesticide or parasiticide in at least another container or compartment of a container represents another important aspect of the present invention.

Examples

The basis for the preparation of an aqueous low-dose solution according to the present invention is the DCL-PEG concentrate, which is a solution of DCL in PEG. Depending on the molecular weight of the PEG, this concentrate is liquid or a waxy solid. Since PEG is very soluble in water, the preparation of a 'ready-to-use' solution in water is extremely simple. One has only to dilute the appropriate amount of the DCL-PEG concentrate in the correct amount of water to ensure accuracy of the dosage. If the amount of water is too low, one observes precipitation of the compound, which is clearly not desirable. However with the aqueous low-dose solution according to the present invention precipitation is anyhow not a problem. Example 1 : Liquid PEG-Concentrate - Preparation of 100 ml of a DCL solution in PEG 200 and ready-to-use aqueous solution.

(A) Approximately 80 mL of PEG 200 is placed in a volumetric flask. 5.0 g of DCL is added. The mixture is stirred until a clear solution is obtained. PEG 200 is added to 100 ml volume. The solution contains 50 mg DCL per mL .

(B) 20 mL of the stock solution resulting from (A) is added to 980 mL of water under stirring. A clear ready-to-use solution containing 1 mg DCL per mL (= 1000 ppm) is obtained.

Example 2: Semi-solid PEG-Concentrate Preparation of 100 ml of a DCL solution in PEG with a medium molecular weight.

(C) 95 g of PEG 1000 is heated to approximately 50⁰C. 5 g of DCL is dissolved under stirring and cooled down to room temperature. The result is a PEG paste.

(D) 20 g of the paste is dissolved in water and made up to give 1 L solution. A clear ready-to-use solution containing 1 mg DCL per mL (= 1000 ppm) is obtained.

Example 3: Solid PEG Concentrate - Preparation of granules consisting of the solid DCL solution in PEG with a high molecular weight.

(E) 95 g of Macrogol™ 4000, which is a long linear PEG 4000, is melted at a temperature of approximately 70⁰C - 75°C. 5 g of DCL is added and stirred for approximately 10 minutes until a homogeneous blend is obtained. The homogeneous mass is discharged onto stainless steel cooling trays and is let to solidify either at room temperature or in a cooler. The solid mass is milled using a suitable mill and sieved through a 1 mm sieve.

(F) 20 g of the granules is dissolved in water and made up to give 1 L solution. A clear ready-to-use solution containing 1 mg DCL per mL (= 1000 ppm) is obtained.

In the same way as described under Examples 1 to 3 one can prepare additional PEG-DCL concentrates and ready-to-use solution adapted to the actual need.

Example 4: Larval implant studies - Jetting/spray treatment of sheep with a low-dose aqueous DCL-PEG solution against Lucilia cuprina

INTRODUCTION: Early efficacy testing of compounds and formulations for the protection of sheep against blowfly strike involves placing fly larvae or eggs on the fleece of treated sheep. These are known as 'implants'. Larvae or eggs are placed in the wool above a small wound on the skin with the aim of creating an artificial strike. This strike is assessed daily to establish efficacy of the compound.

LARVAL IMPLANT STUDIES: Generally there are two methods of treatment. Jetting Compound Studies: This is a treatment of the whole sheep. The specified volume of jetting fluid is applied as per protocol, using a jetting system or by simulating jetting using gloved hands to massage the liquid into the fleece as it is poured onto the sheep. For testing purposes jetting can also be carried out with a minimal volume of the formulation by treating only portions of the fleece. This partial treatment can be carried out in the following manner:

1. Restrain each animal individually in a cradle in lateral recumbency.

2. Spray the test liquid onto the sheep according to the protocol. The treatment liquid is colored with a food dye to enable subsequent identification of the treatment zone.

Backline Spray-on Studies: Each animal is restrained individually in a head bail or small race. The compound is applied to the fleece by using a suitable applicator. A food dye is added to the compound to identify the treatment zone.

Implantation of the eggs or larvae: Larvae are implanted at time 0, at predefined intervals following treatment. Depending on the protocol or efficacy and persistency of the compound, this process could take a number of months.

1. The implanting is performed with each sheep restrained in a head bail.

2. The wool is parted either within or on the edge of the treated zone to expose the skin.

3. The parted wool is sprayed with a fine mist of water to wet the whole region.

4. A small cut is made in the skin to establish a serum flow.

5. A mass of several hundred eggs or first instar larvae of Lucilia cuprina (10 - 12 hours old and approximately 1 mm long) is placed onto the wool in the parting, 1 - 2 cm from the tip of the fleece, or in the top one third of the staple length. The aim is to encourage the larvae to migrate through the chemically treated zone en-route to skin level.

6. The parting is closed.

7. The site is identified by placing a bulldog clip lateral to the implant, making sure the eggs or larvae are not crushed.

Assessment: The individual sites are inspected at approximately 24, 48 and 72 hours after the implanting of the eggs or larvae to assess the viability of the developing strike. The viability for each implant on individual sheep is graded and recorded by using the following codes:

AT - An established strike, larvae are not affected, feeding at skin level, actively seeking more nourishment thus increasing the size of the strike. In this case the implant must be immediately terminated by clipping out the wool around the cut, removing the larvae and drying the site with sodium tetraborate powder. A1 - Larvae are showing only a slight effect, they are feeding at the skin level and move freely close to the cut looking for more food.

A2 - Larval development is clearly disturbed, remaining at the skin level but are scattered around the cut, larvae may still be feeding but move slowly and they often vary in size. A3 - Larvae are severely affected, are small in size and their movement is very slow. They are often dispersed in the wool. D - The larvae are dead.

A grading score is given to each implant end point assessment. These are: AT = O, A1 = 1 , A2 = 5, A3 = 7, D = 10. Therefore, with a group of five sheep the maximum group value is 50 (when the end point for each sheep is graded as 'D'). The higher the value the greater the efficacy.

Recording of the assessments: At the 72 hour inspection all live strikes are terminated after the viability of the larvae at the assessment is recorded. The implanting and assessment procedure is repeated for a maximum of six implanting sessions on any one sheep throughout the course of a study.

In a randomized, controlled efficacy study using adult Merino female sheep (n=20), artificial implants with blowfly larvae (diazinon-resistant L. cuprina) are used to determine the ability of two test products to protect sheep from blowfly strike. The sheep are acclimatized to indoor housing pens prior to treatment.

Treatment groups

In week -5 the sheep in groups 1 and 2 are shorn (pre-study preparation). On day -2, all sheep are weighed, inspected by a veterinarian to ensure they are healthy and allocated to their treatment groups. On day 0, the appropriate sheep (groups 2 and 3) are treated with their allocated formulation.

A DCL-PEG 5% concentrate is diluted with water and results in a DCL-PEG 1.25% ready- to-use solution which is applied as a jetting fluid.

Blowfly implants commence 6 weeks post-treatment and continued at fortnightly intervals until protection against fly larval development is lost, or the maximum number of six blowfly implant sessions is reached (week 16).

The efficacy of the test products is determined by comparing the survival of fly larvae on the treated sheep with those measurements taken on the untreated controls. The comparisons are group 1 with group 2 and group 3 with group 4.

Test results (W = week):

Discussion of the test results:

In this study, the 1.25% DCL-PEG formulation provides complete protection to at least week 8 after treatment. After week 8, efficacy starts to decline with several animals having 'A3' strikes at week 10. The surviving larvae at week 10 are still severely affected by DCL; this determined by their small size and sluggish movement. By week 12, protection is lost. With this formulation the protection period is defined as 8-10 weeks.

When DCL-PEG 5% is diluted in water and applied via spraying as a jetting fluid. Full protection is achieved to at least 10 weeks after treatment. After this point, individual animal protection varies. One animal maintains 'A3' strikes for several implant sessions, whilst a second requires its strikes to be physically terminated. With this formulation the protection period is defined as 10-12 weeks.

Example 5: Treatment of nuisance fly (Musca domestica) with dicyclanil and an adulticide

Combining an adulticide and a larvicide as a single end-use product for the control of Musca spp. and other nuisance flies provides a unique and previously unidentified opportunity for farmers to improve the hygiene of their livestock stables and barns, feedlots, pig sties and poultry houses. Separate laboratory and field experiments are conducted to demonstrate the contribution and role of possible adulticides and DCL to the efficacy against the pests infesting such housing facilities.

In laboratory based experiments, lambda-cyhalothrin is applied at 100-1000 mg active ingredient/m² and is extremely effective in the 'knockdown' control of Musca spp.. In fact, close to 100% efficacy is achieved in less than 5 hours even at the lower concentration, lambda-cyhalothrin proves to be more rapid and effective than the other adulticides such as spinosad or thiamethoxam. However, a problem with lambda-cyhalothrin and certain other adulticides is that they cease being effective when covered up with waste material (e.g. feces, fresh bedding). In simulated laboratory experiments, this is proven when lambda- cyhalothrin-treated media is covered with sawdust; efficacy is immediately inhibited.

The efficacy of DCL is evaluated in field studies and it turns out to be very effective for the longer-term control of larval stages of flies. Because DCL is an IGR, it is not active against adult flies. When applied as an aqueous DCL-PEG solution at 0.1 mg DCL/m², DCL is able to restrict the development of Musca spp. for 6-8 weeks despite the accumulation of waste material on top of it. Thus, when lambda-cyhalothrin and DCL are applied jointly, the former controls existing and hatching adult flies, while the DCL provides the longer-term control of developing larval stages, thereby providing the farmer complete control of fly populations.

Combating housefly in the hygiene area: An example of a preferred DCL-lambda- cyhalothrin combination is DCL-PEG concentrate containing 5% w/w DCL and 10% w/w lambda-cyhalothrin in PEG-200 that can be dissolved in water to result in a ready-to-use low dose aqueous solution. A preferred treatment regime in the hygiene area is the application of 50-250 mg/m², preferably 80-120 mg/m²' most preferably 100 mg/m² of lambda- cyhalothrin and 150-300 mg/m², preferably 180-220 mg/m² most preferably 200 mg/m² of DCL, which is advantageously applied to the manure.

The most preferred embodiments of the current invention are listed in the following under items A to R and combinations of said items A to R :

A. Dicyclanil-polyethylene glycol concentrate (DCL-PEG concentrate) comprising 3 to 20% w/w dicyclanil (DCL) in polyethylene glycol (PEG). i) Said dicyclanil-polyethylene glycol concentrate comprising low molecular weight

PEG containing 3% to 6%, preferably about 5% DCL dissolved in said low molecular weight PEG. ii) Said dicyclanil-polyethylene glycol concentrate comprising medium molecular weight PEG containing 3% to 5%, preferably about 5% DCL dissolved in said medium molecular weight PEG. iii) Said dicyclanil-polyethylene glycol concentrate comprising high molecular weight

PEG containing 5% to 20% or even more DCL dispersed in said high molecular weight PEG.

B. Said dicyclanil-polyethylene glycol concentrate characterized in that it is basically free of water.

C. Said dicyclanil-polyethylene glycol concentrate characterized that the polyethylene glycol has a molecular weight of about 200 to about 8O00 or is a mixture of polyethylene glycols of different molecular weight.

D. Said dicyclanil-polyethylene glycol concentrate characterized that it is at room temperature liquid.

E. Said dicyclanil-polyethylene glycol concentrate characterized that it is at room temperature semi-solid.

F. Said dicyclanil-polyethylene glycol concentrate characterized that it is at room temperature solid.

G. The use of such a dicyclanil-polyethylene glycol concentrate 6 for the preparation of an aqueous low-dose solution comprising 0.5 to 2.5% of dicyclanil, preferably 1 to 1.5% of dicyclanil, most preferably 1.25% of dicyclanil.

H. The use of said aqueous low-dose dicyclanil-polyethylene glycol solution for combating insects on animals or insects in the environmental hygiene area. I. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 8 for combating blowfly. K. The use of said aqueous low-dose dicyclanil-polyethylene glycol solution for combating flies in the environmental hygiene area. L. Said aqueous low-dose dicyclanil-polyethylene glycol solution characterized in that it comprises apart from the dicyclanil a further pesticide or parasiticide.

M. Said aqueous low-dose dicyclanil-polyethylene glycol solution characterized in that said further pesticide or parasiticide is one or more further pesticide or parasiticide selected from the group consisting of insect adulticides; broad-band insecticides, broad-band acaricides and nematocides.

N. Said aqueous low-dose dicyclanil-polyethylene glycol solution characterized in that said further pesticide or parasiticide is a pyrethroid ester insecticides selected from the group consisting of acrinathrin; allethrin; bioallethrin; barthrin; bifenthrin; bioethanomethrin; cyclethrin; cycloprothrin; cyfluthrin; beta-cyfluthrin; cyhalothrin; gamma-cyhalothrin; lambda-cyhalothrin; cypermethrin; alpha-cypermethrin; beta-cypermethrin; theta- cypermethrin; zeta-cypermethrin; cyphenothrin; deltamethrin; dimefluthrin; dimethrin; empenthrin; fenfluthrin; fenpirithrin; fenpropathrin; fenvalerate; esfenvalerate; flucythrinate; fluvalinate; tau-fluvalinate; furethrin; imiprothrin; metofluthrin; permethrin; biopermethrin; transpermethrin; phenothrin; prallethrin; profluthrin; pyresmethrin and resmethrin; bioresmethrin; cismethrin; tefluthrin; terallethrin; tetramethrin; tralomethrin; and transfluthrin, preferably lambda-cyhalothrin.

O. An aqueous ready-to-use low dose solution consisting substantially of dicyclanil, PEG and water.

P. Use of the dicyclanil-polyethylene glycol concentrate according as characterized above for the preparation of a veterinary composition against blowfly.

Q. A physical mixtures comprising DCL and at least one additional pesticide or parasiticide.

R. A kit of parts comprising a DCL-PEG concentrate in one container or compartment of a container, and at least an further PEG-concentrate containing a different pesticide or parasiticide in at least another container or compartment of a container

A 'kit of parts' is within the present invention an arrangement of either at least two different containers or an arrangement of at least two different compartments of the same container, containing a PEG concentrate, whereby said concentrates are foreseen to be diluted with water to result in a ready-to-use aqueous formulation.

Claims

What is claimed is

1. Dicyclanil-polyethylene glycol concentrate (DCL-PEG concentrate) comprising 3 to 20% w/w dicyclanil (DCL) dissolved in polyethylene glycol (PEG).

2. Dicyclanil-polyethylene glycol concentrate according to claim 1 characterized in that i) the DCL-PEG concentrate comprises low molecular weight PEG containing 3% to

6% DCL dissolved in said low molecular weight PEG, or ii) the DCL-PEG concentrate comprises medium molecular weight PEG containing

3% to 5% DCL dissolved in said medium molecular weight PEG, or iii) the DCL-PEG concentrate comprises high molecular weight PEG containing 5% to

20% DCL dispersed in said high molecular weight PEG.

3. Dicyclanil-polyethylene glycol concentrate according to any one of claims 1 and 2 characterized in that it is basically free of water.

4. Dicyclanil-polyethylene glycol concentrate according to claim 1 characterized that the polyethylene glycol has a molecular weight of 200 to 8O00 or is a mixture of polyethylene glycols of different molecular weight between 200 and 8000.

5. Dicyclanil-polyethylene glycol concentrate according to claim 1 characterized that it is liquid at room temperature.

6. Dicyclanil-polyethylene glycol concentrate according to claim 1 characterized that it is semi-solid at room temperature.

7. Dicyclanil-polyethylene glycol concentrate according to claim 1 characterized that it is solid at room temperature.

8. The use of a dicyclanil-polyethylene glycol concentrate according to any one of claims 1 to 7 for the preparation of an aqueous low-dose solution comprising 0.5 to 2.5% by weight and preferably 1 to 1.5% by weight of dicyclanil, in each case relative to the weight of the entire solution.

9. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 8 for combating insects on animals or insects in the environmental hygiene area.

10. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 9 for combating blowfly.

1 1. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 9 for combating flies in the environmental hygiene area.

12. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 8 characterized in that it comprises apart from the dicyclanil a further pesticide or parasiticide.

13. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 12 characterized in that said further pesticide or parasiticide is one or more further pesticide or parasiticide selected from the group consisting of insect adulticides; broad-band insecticides, broadband acaricides and nematocides.

14. Aqueous low-dose dicyclanil-polyethylene glycol solution of claim 12 characterized in that said further pesticide or parasiticide is a pyrethroid ester insecticides selected from the group consisting of acrinathrin; allethrin; bioallethrin; barthrin; bifenthrin; bioethanomethrin; cyclethrin; cycloprothrin; cyfluthrin; beta-cyfluthrin; cyhalothrin; gamma-cyhalothrin; lambda- cyhalothrin; cypermethrin; alpha-cypermethrin; beta-cypermethrin; theta-cypermethrin; zeta- cypermethrin; cyphenothrin; deltamethrin; dimefluthrin; dimethrin; empenthrin; fenfluthrin; fenpirithrin; fenpropathrin; fenvalerate; esfenvalerate; flucythrinate; fluvalinate; tau- fluvalinate; furethrin; imiprothrin; metofluthrin; permethrin; biopermethrin; transpermethrin; phenothrin; prallethrin; profluthrin; pyresmethrin and resmethrin; bioresmethrin; cismethrin; tefluthrin; terallethrin; tetramethrin; tralomethrin; and transfluthrin, preferably lambda- cyhalothrin.

15. Aqueous ready-to-use low dose solution consisting substantially of dicyclanil, PEG and water.

16. Use of the dicyclanil-polyethylene glycol concentrate according to claim 1 for the preparation of a veterinary composition against blowfly.