AU718950B2

AU718950B2 - Control of ectoparasites

Info

Publication number: AU718950B2
Application number: AU31869/97A
Authority: AU
Inventors: Noreen Hanna; Vincent Mcnally; James Patrick Morgan; Kolazi S Narayanan
Original assignee: Bimeda Research and Development Ltd; ISP Investments LLC
Current assignee: Zoetis Broomhill IP Ltd; ISP Investments LLC
Priority date: 1996-05-15
Filing date: 1997-05-14
Publication date: 2000-05-04
Anticipated expiration: 2017-05-14
Also published as: GB2326341B; EP0901321A1; ZA974164B; IE960347A1; NZ332213A; WO1997042816A1; GB9821315D0; AU3186997A; AR007143A1; GB2326341A

Description

BIME07/C/AU -1- "Control of Ectoparasites" Introduction The invention relates to the control of ectoparasites in animals and in particular to the prevention and control of blowfly strike and/or for the treatment and control of lice, keds and ticks and/or for the treatment and control of scab in animals, especially sheep.

Currently, insecticides for controlling ectoparasites in animals are formulated as emulsifiable concentrates. On dispersion of such concentrates in water generally particles in the micron size range are produced. This particle size range adversely effects the spread of the insecticide on the animal. In addition, known emulsifiable concentrates are generally formulated using hydrocarbon solvents which in some cases are not environmentally friendly.

This invention is therefore directed towards providing an improved method for preventing and controlling ectoparasites in animals and to an animal wetting solution used in the method which will overcome at least some of these difficulties.

Statements of Invention According to one aspect the invention provides a method for making an animal wetting solution for preventing and controlling ectoparasites in animals 25 comprising diluting an aqueous emulsion concentrate containing 25 to 250 g/litre of a substantially water insoluble insecticide in a concentrate delivery system containing a surfactant system, a buffer to achieve a pH of from 3.5 to 9, and a cosolvent comprising a mixture of an N-CI to C 4 alkyl pyrrolidone and an N-C 6 to

C

1 4 alkyl pyrrolidone, the N-CI to C 4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of from 18 to 22 wt%/ and the N-C 6 to C 1 4 alkyl S pyrollidone BIME07/C/AU -2being present in an amount of from 2 to 15 wt%, to form a homogenous, aqueous animal wetting solution containing from 25 to 500 mg/litre of the insecticide, the insecticide being effective against blowfly, lice, keds, ticks, scab and other insects which infect animals.

Preferably the emulsion concentrate is an aqueous microemulsion, macroemulsion or hydrogel concentrate. Most preferably the emulsion concentrate is an aqueous microemulsion concentrate.

In a particularly preferred embodiment the insecticide is a pyrethroid insecticide, especially cypermethrin.

Preferably the concentrate contains from 50 to 150 g/litre of an insecticide most preferably approximately 100 g/litre of an insecticide.

Preferably the wetting solution contains from 80 to 120 mg/litre of an insecticide ideally approximately 100 mg/litre of an insecticide. This concentration is particularly advantageous for preventing and controlling blowfly strike and/or for the treatment and control of lice, keds and ticks especially in sheep.

Preferably the wetting solution contains from 180 to 220 mg/litre of an insecticide ideally approximately 200mg/litre of an insecticide. This concentration is particularly advantageous for the treatment and/or control of scab, especially in sheep.

In a preferred embodiment of the invention the solution is a wetting solution and the method includes the step of topping up the solution with a solution formed by diluting the concentrate at a dilution ratio of from 1:250 to 1:1000 by volume, preferably approximately 1:500 by volume.

BIME07/C/AU -3- According to one aspect the invention provides a method for making an animal wetting solution for preventing and controlling blowfly strike and/or for the treatment and control of lice, keds and ticks in sheep comprising diluting an aqueous microemulsion concentrate containing approximately 100 g/litre of cypermethrin in a concentrate delivery system containing a surfactant system, a buffer to achieve a pH of from 3.5 to 9, and a co-solvent comprising a mixture of an N-C 1 to C 4 alkyl pyrrolidone and an N-C 6 to C 1 4 alkyl pyrrolidone, the N-CI to

C

4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of from 18 to 22 wt% and the N-C 6 to C 14 alkyl pyrollidone being present in an amount of from 2 to 15 wt% to form a homogenous aqueous sheep dipping solution containing approximately 100 mg/litre of cypermethrin.

Another aspect of the invention provides a method for making an animal wetting solution for the treatment and/or control of scab in sheep comprising diluting an 15 aqueous microemulsion concentrate containing approximately 100 g/litre of cypermethrin in a concentrate delivery system containing a surfactant system, a buffer to achieve a pH of from 3.5 to 9, and a co-solvent comprising a mixture of an N-Ci to C 4 alkyl pyrrolidone and an N-C 6 to C 1 4 alkyl pyrrolidone, the N-Ci to

C

4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of 20 from 18 to 22 wt% and the N-C 6 to C 14 alkyl pyrollidone being present in an amount of from 2 to 15 wt% to form a homogenous aqueous sheep dipping "solution containing approximately 200 mg/litre of cypermethrin.

*o Preferably the N-C, to C 4 alkyl pyrrolidone is N-methyl-2-pyrrolidone. Most 25 preferably the N-methyl-2-pyrrolidone is present in the emulsion concentrate in an amount of approximately 20 wt%.

Preferably the N-C 6 to C 1 4 alkyl pyrrolidone is N-octyl-2-pyrrolidone and is preferably present in an amount of approximately 9 wt%.

BIME07/C/AU -4- In a preferred embodiment the surfactant system is a mixture of surfactants and includes an alkoxylated alkyl phenol. Preferably the alkoxylated alkyl phenol is present in the emulsion concentrate in an amount of from 50 to 54 wt%.

Preferably the alkoxylated alkyl phenol is ethoxylated nonyl-phenol and is present in the microemulsion in an amount of approximately 52 wt%.

In a preferred embodiment of the invention the surfactant system includes a nonionic surfactant. Preferably the non-ionic surfactant is present in the emulsion concentrate in an amount of from 5% to 80 wt% most preferably from 8 to 10 wt% and ideally approximately 9 wt%. In one embodiment the non ionic surfactant is a difunctional block copolymer terminating in primary hydroxyl groups.

In one embodiment of the invention the buffer is selected from one or more of a phosphated alkoxylated alkylphenol, a hydrophobic acid, or a hydrophobic base.

15 The buffer is preferably present in the emulsion concentrate in an amount of from 0.025 to 2 wt% most preferably from 0.5 to 1.5 wt% and ideally approximately 1 wt%.

9 *e In a preferred embodiment the insecticide is an acid stable insecticide and the 20 buffer is present in an amount to achieve a pH of from 3.5 to 6.5 preferably from to 5.5 and ideally approximately 4.

9*9999 The buffer may be a phosphated ethoxylated nonyl-phenol.

S 25 When the insecticide is a base stable insecticide the buffer is preferably present in an amount to achieve a pH of from 8 to 9.

In a further aspect the invention provides an animal wetting solution containing from 25 to 500 mg/litre of an ectoparasiticidal insecticide effective against blowfly, lice, keds, ticks, scab and other insects which infest animals; the animal ,wetting solution being derived from an ectoparasiticidal concentrate containing:- BIME07/C/AU to 250 g/litre of the insecticide; a co-solvent system comprising a mixture of an N-C 1 to C 4 alkyl pyrrolidone and N-C 6 to N 1 4 alkyl pyrrolidone, the N-CI to C 4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of from 18 to 22 wt% and the N-C 6 to C 14 alkyl pyrrolidone being present in an amount from 2 to 15 wt%; a surfactant system; and a buffer in an amount to achieve a pH from 3.5 to 9.

Preferably the ectoparasiticidal concentrate is a microemulsion or macroemulsion concentrate.

Preferably the concentrate contains 25 to 100 g/litre of an ectoparasiticidal i insecticide most preferably from 50 to 150 g/litre.

C

*o.

20 In a particularly preferred embodiment the insecticide is a pyrethroid insecticide especially cypermethrin.

Preferably the animal wetting solution additionally contains a thickener to form a

CC

hydrogel. Most preferably the thickener is a hydroxy alkyl cellulose, a crosslinked alkyl vinyl ether/maleic copolymer or an ethoxylated phosphoric acid compound.

Preferably the N-Ci- to C 4 alkyl pyrrolidone is N-methyl-2-pyrrolidone.

Preferably the N-methyl-2-pyrrolidone is present in the concentrate in an amount of approximately 20 wt%.

BIME07/C/AU -6- In a preferred embodiment the N-C 6 to C 1 4 alkyl pyrrolidone is N-octyl-2pyrrolidone and is preferably present in the concentrate in an amount of approximately 9 wt%.

In a preferred embodiment the surfactant system is a mixture of surfactants.

Preferably the surfactant system includes an alkoxylated alkyl phenol, most preferably the alkoxylated alkyl phenol is present in the emulsion concentrate in an amount of from 50 to 54 wt%.

Preferably the alkoxylated alkyl phenol is ethoxylated nonyl-phenol which is present in the microemulsion in an amount of approximately 52 wt%.

In a preferred embodiment the surfactant system includes a non-ionic surfactant which is preferably present in the emulsion concentrate in an amount of from 5 to 15 80 wt% most preferably from 8 to 10 wt%, ideally approximately 9% w/w.

Preferably the non ionic surfactant is a difunctional block copolymer terminating in primary hydroxyl groups.

4 In one embodiment of the invention the buffer is selected from one or more of a 20 phosphated alkoxylated alkylphenol, a hydrophobic acid, or a hydrophobic base.

Preferably the buffer is present in the emulsion concentrate in an amount of from 0.025 to 2 wt%, most preferably from 0.5 to 1.5 wt% and ideally approximately 1 wt%.

a 25 When the insecticide is an acid stable insecticide the buffer is preferably present in an amount to achieve a pH of from 3.5 to 6.5, preferably from 3.5 to 5.5 and ideally approximately 4.

The buffer may be a phosphated ethoxylated nonyl-phenol.

6a When the insecticide is a base stable insecticide the buffer is preferably present in an amount to achieve a pH of from 8 to 9.

The animal wetting solution may be in the form of an animal dipping solution, a pour-on formulation or in the form of a pet shampoo formulation.

The formulations of the present invention have numerous advantages including at least one of:lanolin wetting and spreading power; t 045 r o,

S

<i S S. o55.

S

S*

SS

'ft 0 o BIME07/C/AU r- 6b extended insecticidal efficiency and animal protection to 8 weeks; formation of stable homogenous aqueous emulsions of water insoluble insecticides; complexing ability and compatibility of the co-solvent mixture with a wide range of insecticidal agents; and clarity and non-staining properties of the formulations.

In particular, N-C 1 to C 4 pyrrolidones have coating and insecticide complexing properties. N-C 6 to C 1 8 alkyl pyrrolidones have lanolin wetting and spreading 15 properties and are capable of forming micelles when used in the present emulsion concentrates with the ethoxylated nonylphenol detergent and the ethylene oxidepropylene oxide-ethylene oxide block copolymer.

Detailed Description of the Invention The invention will be more clearly understood from the following description thereof given by way of example only.

The formulation given in the Example includes the following branded chemicals: Pluronic L31 (Trade Mark of BASF) is a difunctional block copolymer terminating in primary hydroxyl groups. It is a non-ionic surfactant.

IGEPAL CO-630 (Trade mark of Rhone- Poulenc) is an ethoxylated nonylphenol detergent and acts as an emulsifier.

WO 97/42816 PCT/IE97/00038 7 Rhodofac RE-610 (Trade Mark of Rh6ne Poulenc) is a phosphated ethoxylated nonylphenol buffer/emulsifier.

The N-methyl-2-pyrrolidone used was AGSOL Exl available from ISP Europe.

The N-octyl-2-pyrrolidone used was AGSOL Ex8 available from ISP Europe.

Example A microemulsion concentrate was prepared as follows.

Batch Size: 1000 Kg Cypermethrin N-methyl-2-pyrrolidone N-octyl-2-pyrrolidone Igepal CO-630" Pluronic L31" Rhodafac RE 610" Quantity (Kg) 100.000 (100% activity) 197.580 86.330 519.760 86.330 10.000 The N-methyl 2-pyrrolidone is placed in a batch mixing vessel having a volume of 1200 litres and fitted with a propeller mixer. The N-octyl-2-pyrrolidone is then added to the batch vessel and the contents are mixed. The Igepal CO-630" is then added to the vessel and mixing is continued. Pluronic-L31" is added to the vessel with continuing mixing.

The Rhodafac RE 610" is then added and mixing is continued for 30 minutes.

Cypermethrin is prepared by liquifying at a temperature of from 37 0 C to 40 0

C.

WO 97/42816 PCT/IE97/00038 8 The liquified cypermethrin is added to the vessel and mixing is continued for 60 minutes.

The pale yellow liquid thus formed is poured into multilayered plastics containers having an internal polyamide layer. The containers are of 1 litre, 2 litre and 5 litre capacity.

The co-solvents N-methyl-2-pyrrolidone and N-octyl-2pyrrolidone facilitate dissolution.

The two surfactants, Igepal CO-630" and Pluronic-L31" form micelles when the microemulsion concentrate is added to water. These micelles provide a means of incorporating the active into an aqueous vehicle at a concentration greater than the solubility of the active. Rhodafac RE 610" acts as a buffer.

Cypermethrin normally has a solubility of from 0.01 to 0.2 mg/l at 20 0

C.

Using the microemulsion concentrate of the invention, however, a solubility of greater than 100 mg/l can be achieved.

The microemulsion concentrate has the following analysis: Cypermethrin (Cis/Trans 80:20) 10% w/w N-methyl-2-pyrrolidone 19.758% w/w N-octyl-2-pyrrolidone 8.633% w/w Igepal CO-630" 51.976% w/w Pluronic L31" 8.6333% w/w Rhodafac RE 610" 1.0% w/w The microemulsion concentrate is used as follows.

WO 97/42816 PCT/IE97/00038 9 A dip bath was filled with the required quantity (typically 1000 litres) of clean water. A measured volume of the microemulsion concentrate is poured into the water at a rate of 10 ml of microemulsion concentrate per litres of water to achieve the desired strength of 100 mg/l. After thorough stirring, sheep are immersed in the bath until the fleece is completely saturated with the dip wash. The sheep's head is plunged under at least twice.

If the volume of dip in the bath has fallen by no more than 10%, it may be replenished at a rate of 10 ml per litres of added water.

WO 97/42816 PCT/IE97/00038 10 TRIAL 1 Blowfly Myiasis Three separate farms and a total of 1500 sheep were involved in the trial. Adult sheep and lambs of mixed breeds were dipped for 30 seconds in a dip bath prepared as described above. Untreated animals were chosen at random and consisted of at least 10% of the trial groups.

The overall percentage strike rate was as follows: Treated Sheep Untreated Sheep Farm 1 2.6% 28% Farm 2 2.7% 28.75% Farm 3 2.5% 23.8% The trial showed that the product is effective for 4-7 weeks in preventing the development of Blowfly myiasis of sheep.

TRIAL 2 Infestation with Psoroptes Ovis (Scab) 23 sheep were artificially infested with a medium virulent -(CVL) strain of Psoroptes Ovis. The sheep were plunge dipped for one minute each; as described above. Lesion areas and mite burdens were determined on day 0 (pretreatment) and on days 27 and 58 post treatment.

Observations on adverse treatment reactions were made immediately and at 6 and 24 hours after treatment. At the end of the trial, all sheep were crucially assessed and skin scrapings were taken from areas of lesion not responding to treatment.

The product was found to be 91.3% effective in curing the infested sheep and 99.6% effective in reducing the numbers of infested sheep.

WO 97/42816 PCT/IE97/00038 11 TRIAL 3 Infestation with Sheep Lice (Bovicola Ovis) and sheep ked (Metaphaga Ovis) fully fleeced sheep with lice and ked infestations were dipped as described above. Dipwash samples were taken.

Live lice or keds were found on 2 animals 24 hours post dipping. No live lice or keds were found on dipped sheep 7 days post treatment. Treated sheep remained free of lice and keds for the remainder of the trial 42 days post dipping.

In contrast, untreated controls maintained moderate/high burdens of lice and keds for the trial duration.

While the specific formulation refers to RHODOFAC RE610 as a buffer, it will be appreciated that the buffer may be selected from a hydrophobic acid or base alternatives such as nonylphenol phosphoric acid, tristearyl phenyl ethoxylated phosphonic acid and dodecylbenzene sulfonic acid. The insecticide matrix may require buffering to a pH of 3 to 6.5, preferably 3.5 to 5.5 or as close to pH 4 as convenient for acid stable insecticides and as close to pH 8 to 9 for base stable insecticides.

Cypermethrin retention in the matrix has been investigated at different pH levels. It has been found that a pH of about 4 is most desirable for stability.

It will be appreciated that while a microemulsion concentrate has been described, macroemulsions should not be excluded as these also give homogeneous dispersions, even though they are somewhat cloudy by reason of particle size >2500A. A hydrogel may also be used where a thickener such as hydroxy alkyl cellulose, CARBOPOL (Trade Mark), cross linked lower vinyl ether/maleic anhydride copolymers (STABILEZE Trade Mark) or [IC 3

H

27

(OC

2

H

4 9 ],n WO 97/42816 PCT/IE97/00038 12 PO(OH)n (where m n 3) are employed. These may be dabbed on infected areas for localised insecticidal effect or used as a pour-on.

The invention is not limited to the embodiments hereinbefore described which may be varied in detail.

Claims

1. A method for making an animal wetting solution for preventing and controlling ectoparasites in animals comprising diluting an aqueous emulsion concentrate containing 25 to 250 g/litre of a substantially water insoluble insecticide in a concentrate delivery system containing a surfactant system, a buffer to achieve a pH of from 3.5 to 9, and a co- solvent comprising a mixture of an N-Ci to C 4 alkyl pyrrolidone and an N- C 6 to C 14 alkyl pyrrolidone, the N-C 1 to C 4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of from 18 to 22 wt% and the N- C 6 to C 1 4 alkyl pyrollidone being present in an amount of from 2 to 15 wt%, to form a homogenous, aqueous animal wetting solution containing from to 500 mg/litre of the insecticide, the insecticide being effective against blowfly, lice, keds, ticks, scab and other insects which infect animals.

2. A method as claimed in claim 1 wherein the emulsion concentrate is an aqueous microemulsion, macroemulsion or hydrogel concentrate.

3. A method as claimed in claim 1 or 2 wherein the emulsion concentrate is S 20 an aqueous microemulsion concentrate.

4. A method as claimed in any preceding claim wherein the insecticide is a pyrethroid insecticide. 25 5. A method as claimed in claim 4 wherein the pyrethroid insecticide is cypermethrin.

6. A method as claimed in any of claims 1 to 5 wherein the concentrate contains from 50 to 150 g/litre of an insecticide. BIME07.AU

7. A method as claimed in any of claims 1 to 6 wherein the concentrate contains approximately 100 g/litre of an insecticide.

8. A method as claimed in any of claims 1 to 7 wherein the wetting solution contains from 80 to 120 mg/litre of an insecticide.

9. A method as claimed in any of claims 1 to 8 wherein the wetting solution contains approximately 100 mg/litre of an insecticide.

10. A method as claimed in any of claims 1 to 7 wherein the wetting solution contains from 180 to 220 mg/litre of an insecticide.

11. A method as claimed in any of claims 1 to 7 or 10 wherein the wetting solution contains approximately 200mg/litre of an insecticide.

12. A method as claimed in any of claims 1 to 11 wherein the solution is a wetting solution and the method includes the step of topping up the solution with a solution formed by diluting the concentrate at a dilution ratio of from 1:250 to 1:1000 by volume. S.

13. A method as claimed in claim 12 wherein the top up solution is formed by diluting the concentrate at a dilution ratio of approximately 1:500 by volume. 25 14. A method for making an animal wetting solution for preventing and *controlling blowfly strike and/or for the treatment and control of lice, keds and ticks in sheep comprising diluting an aqueous microemulsion concentrate containing approximately 100 g/litre of cypermethrin in a concentrate delivery system containing a surfactant system, a buffer to achieve a pH of from 3.5 to 9, and a co-solvent comprising a mixture of an N-Ci to C 4 alkyl pyrrolidone and an N-C 6 to C 1 4 alkyl pyrrolidone, the N- BIME07.AU C 1 to C 4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of from 18 to 22 wt% and the N-C 6 to C 1 4 being present in an amount of from 2 to 15 wt%, to form a homogenous aqueous sheep dipping solution containing approximately 100 mg/litre of cypermethrin. A method for making an animal wetting solution for the treatment and/or control of scab in sheep comprising diluting an aqueous microemulsion concentrate containing approximately 100 g/litre of cypermethrin in a concentrate delivery system containing a surfactant system, a buffer to achieve a pH of from 3.5 to 9, and a co-solvent comprising a mixture of an N-Ci to C 4 alkyl pyrrolidone and an N-C 6 to C 1 4 alkyl pyrrolidone, the N- CI to C 4 alkyl pyrrolidone being present in the emulsion concentrate in an amount of from 18 to 22 wt% and the N-C 6 to C 1 4 being present in an amount of from 2 to 15 wt%, to form a homogenous aqueous sheep dipping solution containing approximately 200 mg/litre of cypermethrin.

16. A method as claimed in any preceding claim wherein the N-C, to C 4 alkyl pyrrolidone is N-methyl-2-pyrrolidone. 0 z20 17. A method as claimed in claim 16 wherein the N-methyl-2-pyrrolidone is present in the emulsion concentrate in an amount of approximately wt%.

18. A method as claimed in any preceding claim wherein the N-C 6 to C 1 4 alkyl 25 pyrrolidone is N-octyl-2-pyrrolidone.

19. A method as claimed in claim 18 wherein the N-octyl-2-pyrrolidone is present in the emulsion concentrate in an amount of approximately 9 wt%.

20. A method as claimed in any preceding claim wherein the surfactant system is a mixture of surfactants. 15a

21. A method as claimed in claim 20 wherein the surfactant system includes an alkoxylated alkyl phenol.

22. A method as claimed in claim 21 wherein the alkoxylated alkyl phenol is present in the emulsion concentrate in an amount of from 50 to 54 wt%.

23. A method as claimed in claim 21 or 22 wherein the alkoxylated alkyl phenol is ethoxylated nonyl-phenol. a. S** o a. a a 16 BIMEO7.AU

24. A method as claimed in claim 23 wherein the ethoxylated nonyl phenol is present in the microemulsion in an amount of approximately 52 wt%.

25. A method as claimed in any of claims 20 to 24 wherein the surfactant system includes a non-ionic surfactant.

26. A method as claimed in claim 25 wherein the non-ionic surfactant is present in the emulsion concentrate in an amount of from 5% to 80 wt%.

27. A method as claimed in claim 26 wherein the non-ionic surfactant is present in the emulsion concentrate in an amount of from 8 to 10 wt%.

28. A method as claimed in claim 27 wherein the non-ionic surfactant is present in an amount of approximately 9 wt%.

29. A method as claimed in any of claims 25 to 28 wherein the non ionic surfactant is a difunctional block copolymer terminating in primary hydroxyl groups. S A method as claimed in any of claims 1 to 29 wherein the buffer is selected from one or more of a phosphated alkoxylated alkylphenol, a hydrophobic acid, or a hydrophobic base. *q S S 25 31. A method as claimed in claim 30 wherein the buffer is present in the emulsion concentrate in an amount of from 0.025 to 2 wt%.

32. A method as claimed in claim 31 wherein the buffer is present in the emulsion concentrate in an amount of from 0.5 to 1.5 wt%. 17 BIME07.AU

33. A method as claimed in claim 31 or 32 wherein the buffer is present in the emulsion concentrate in an amount of approximately 1 wt%.

34. A method as claimed in claim any of claims 1 to 29 wherein the insecticide is an acid stable insecticide and the buffer is present in an amount to achieve a pH of from 3 to A method as claimed in claim 34 wherein the buffer is present in an amount to achieve a pH of from 3.5 to

36. A method as claimed in claim 35 wherein the buffer is present in an amount to achieve a pH approximately 4.

37. A method as claimed in any of claims 30 to 36 wherein the buffer is a phosphated ethoxylated nonyl-phenol.

38. A method as claimed in any one of claims 35-37 wherein the insecticide is a base stable insecticide and the buffer is present in an amount to achieve a pH of from 8 to 9.

39. An animal wetting solution .containing from 25 to 500 mg/litre of an ectoparasiticidal insecticide effective against blowfly, lice, keds, ticks, scab and other insects which infest animals; the animal wetting solution being derived from an ectoparasiticidal concentrate containing:- 25 to 250 g/litre of the insecticide; 9 a co-solvent system comprising a mixture of an N-Ci to C 4 alkyl pyrrolidone and an N-C 6 to N 1 4 alkyl pyrrolidone, the N-Ci to C 4 alkyl pyrrolidone being present in the emulsion concentrate in an 18 BIME07.AU amount of from 18 to 22 wt% and the N-C 6 to C 1 4 alkyl pyrrolidone being present in an amount from 2 to 15 wt%; a surfactant system; and a buffer in an amount to achieve a pH from 3.5 to 9. An animal wetting solution as claimed in claim 39 wherein the ectoparasiticidal concentrate is a microemulsion or macroemulsion concentrate.

41. An animal wetting solution as claimed in claim 39 or 40 wherein the concentrate contains 25 to 100 g/litre of an ectoparasiticidal insecticide.

42. An animal wetting solution as claimed in any of claims 39 to 41 wherein the concentrate contains from 50 to 150 g/litre of an ectoparasiticidal insecticide. 20 43. An animal wetting solution as claimed in any of claims 39 to 42 wherein the insecticide is a pyrethroid insecticide.

44. An animal wetting solution as claimed in claim 43 wherein the insecticide S'.I is cypermethrin.

45. An animal wetting solution as claimed in claim 39 additionally containing a thickener to form a hydrogel.

46. An animal wetting solution as claimed in claim 45 wherein the thickener is a hydroxy alkyl cellulose, a cross-linked alkyl vinyl ether/maleic copolymer or an ethoxylated phosphoric acid compound. BIME07.AU

47. An animal wetting solution as claimed in any of claims 39 to 46 wherein the N-Ci- to C 4 alkyl pyrrolidone is N-methyl-2-pyrrolidone.

48. An animal wetting solution as claimed in claim 47 wherein the N-methyl- 2-pyrrolidone is present in the concentrate in an amount of approximately wt%.

49. An animal wetting solution as claimed in any of claims 39 to 47 wherein the N-C 6 to C 1 4 alkyl pyrrolidone is N-octyl-2-pyrrolidone. An animal wetting solution as claimed in claim 49 wherein the N-octyl-2- pyrrolidone is present in the concentrate in an amount of approximately 9 wt%.

51. An animal wetting solution as claimed in any of claims 39 to 50 wherein the surfactant system is a mixture of surfactants.

52. An animal wetting solution as claimed in claim 51 wherein the surfactant o system includes an alkoxylated alkyl phenol.

53. An animal wetting solution as claimed in claim 52 wherein the alkoxylated alkyl phenol is present in the emulsion concentrate in an amount of from 50 to 54 wt%. 25 54. An animal wetting solution as claimed in claim 52 or 53 wherein the alkoxylated alkyl phenol is ethoxylated nonyl-phenol. An animal wetting solution as claimed in claim 54 wherein the ethoxylated nonyl phenol is present in the microemulsion in an amount of approximately 52 wt%. BIME07.AU

56. An animal wetting solution as claimed in any of claims 53 to 55 wherein the surfactant system includes a non-ionic surfactant.

57. An animal wetting solution as claimed in claim 56 wherein the non-ionic surfactant is present in the emulsion concentrate in an amount of from 5 to wt%.

58. An animal wetting solution as claimed in claim 57 wherein the non-ionic surfactant is present in the emulsion concentrate in an amount of from 8 to 0 110 wt%.

59. An animal wetting solution as claimed in claim 57 or 58 wherein the non- ionic surfactant is present in an amount of approximately 9% w/w.

60. An animal wetting solution as claimed in any of claims 56 to 59 wherein the non ionic surfactant is a difunctional block copolymer terminating in primary hydroxyl groups.

61. An animal wetting solution as claimed in any of claims 39 to 60 wherein the buffer is selected from one or more of a phosphated alkoxylated alkylphenol, a hydrophobic acid, or a hydrophobic base. 9

62. An animal wetting solution as claimed in any of claims 39 to 60 wherein the buffer is present in the emulsion concentrate in an amount of from 0.025 to 2 wt%.

63. An animal wetting solution as claimed in claim 62 wherein the buffer is present in the emulsion concentrate in an amount of from 0.5 to 1.5 wt%. BIMEO7.AU

64. An animal wetting solution as claimed in claim 62 or 63 wherein the buffer is present in the emulsion concentrate in an amount of approximately 1 wt%.

65. An animal wetting solution as claimed in any of claims 62 to 64 wherein the insecticide is an acid stable insecticide and the buffer is present in an amount to achieve a pH of from 3.5 to

66. An animal wetting solution as claimed in claim 65 wherein the buffer is present in an amount to achieve a pH of from 3.5 to

67. An animal wetting solution as claimed in claim 66 wherein the buffer is present in an amount to achieve a pH of approximately

68. An animal wetting solution as claimed in any of claims 39 to 67 wherein the buffer is a phosphated ethoxylated nonylphenol.

69. An animal wetting solution as claimed in any of claims 39 to 64 wherein the insecticide is a base stable insecticide and the buffer is present in an amount to achieve a pH of from 8 to 9.

70. An animal wetting solution as claimed in any of claims 39 to 69 in the form of an animal dipping solution. 25 71. An animal wetting solution as claimed in any of claims 39 to 69 in the form of a pour-on formulation. 22

72. An animal wetting solution as claimed in any of claims 39 to 69 in the form of a pet shampoo formulation. DATED: 25 January, 2000 PHILLIPS ORMONDE FITZPATRICK Attorneys for: BIMEDA RESEARCH AND DEVELOPMENT LIMITED q q i. 090000 0 S. 00 S S 0 i *0q0 0 S0 S SO *0 0 9 S OS 0 @0 *9.S 0 SO iSO q AfniA-islI H69'.doc