AU711820B3 - Anthelmintic formulations - Google Patents

Description

P/00/012 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: ASHMONT HOLDINGS LIMITED Actual Inventor: Colin Manson Harvey Address for Service: A.P.T. Patent and Trade Mark Attorneys GPO Box 772, Adelaide, SA 5001 Invention Title: Anthelmintic Formulations Details of Divisional Application No: 707949 (35604/97) The following statement is a full description of this invention, including the best method of performing it known to me:- 2- TECHNICAL FIELD OF THE INVENTION This invention relates to solutions containing the anthelmintic, praziquantel.

BACKGROUND

In recent years the new anthelmintic compounds of the macrolide group such as avermectins and milbemycins have been drugs of choice for the treatment of internal parasites of sheep, cattle and other farm animals. These compounds offer not only the control of many internal parasites but also external parasites and therefore have become known as endecticides. Their popularity has increased because of their dual activity and 1 0 because of increasing resistance to other traditional anthelmintics like levamisole and the benzimidazoles.

However, unlike the benzimidazoles, the macrolide anthelmintics need to be administered as solutions to be bio-available as in their solid form they are poorly absorbed by the animal. It has therefore been the practice to formulate these compounds by dissolving 1 5 them in solvents before administration.

Some types of parasites, particularly trematodes, that are not controlled by the macrolide endecticides. Important trematodes in sheep for example are Liver Fluke (Fasciola hepatica) and Tapeworm (Monezia spp.).

Previous methods of incorporating anthelmintics that have activity against trematodes have relied on suspending a compound like praziquantel that controls Monezia spp. in an anthelmintic solution. It is more desirable to have dual formulations as solutions as this allows wider application as injectables or drenches.

OBJECT

It is an object of this invention to provide a composition containing an effective amount of 2 5 praziquantel and at least one of the active anthelmintics of the macrolide group or at least one that provides the public with a useful choice.

STATEMENT OF INVENTION In one aspect the invention comprises veterinary composition containing: a) an effective amount of praziquantel; -3 b) an effective amount at least one macrolide anthelmintic selected from the group comprising the avermectins and the milbemycins; and c) a suitable organic solvent capable of dissolving a) and b); wherein the composition is suitable for administration to warm-blooded non-human animals.

Preferably the solvent is an ester or ester-like compound. Certain esters and similar compounds have the benefit of dissolving both praziquantel and the avermectins and milbemycins without being toxic to animals.

1 0 More preferably the solvent is selected from the group consisting of glycerol formal, ethyl lactate, benzyl alcohol, N-methyl-2-pyrrolidone and the like.

Preferably the composition is further dissolved in a carrier selected from the group consisting of monoproylene glycol, oil, water and the like.

Preferably the composition is a solution.

1 5 Preferably the macrolide anthelmintic is present in the composition in the range from 0.1- 2% w/v and the praziquantel is preferably present in the composition in the range from 1- Alternatively the composition is a paste containing: a solution of an effective amount of praziquantel, an effective amount at least one macrolide anthelmintic selected from the group comprising the avermectins and the milbemycins, and a suitable organic solvent; and a thickener.

Preferably the thickener is a solid carrier onto which the solution is absorbed and is selected from the group comprising oat meal flour, methancel, and xanthan gum.

2 5 Preferably the macrolide anthelmintic is present in the paste in the range from 0.1-2% w/v and the praziquantel is preferably present in the composition in the range from 1-10%w/v.

In another aspect the invention provides a method for the treatment of endo- and ectoparasites in a non-human animal by administering to an animal a composition as described above at the rate of 1 ml/5-20 kg of bodyweight.

-4 Preferably the animal is treated every 6-8 weeks or more often as required.

Preferably the composition is administered to the animal as a drench, by injection or as an oral paste.

PREFERRED EMBODIMENT These and other aspects of this invention, which should be considered in all its novel aspects will be apparent from the following examples.

Example 1: Formulation Type: Drench 1 0 Intended Recipient Animals: Sheep, cattle, goats Ingredient %w/v Ivermectin 0.2 Praziquantel Tween 80 10.0 Glycerol Formal 10.0 Benzyl Alcohol Propyl Gallate 0.009 Monopropylene Glycol 40.0 Deionised water 20.0 Disodium EDTA 0.009 Sodium dihydrogen phosphate Disodium hydrogen phosphate Mineral Premix 10.0 Selenium Chelate 0.305 Monopropylene Glycol To volume 100.0 mL The mineral premix is a chelated mineral mixture of Copper, Cobalt and Zinc.

Example 1 is manufactured as follows: 1. To a clean dry mixing vessel add the benzyl alcohol and with stirring add the ivermectin. Stir until completely dissolved.

2. Add the Tween 80 and glycerol formal and stir until completely dispersed.

3. Add the praziquantel while stirring and warm the solution to 50-60°C. Continue stirring until fully dissolved.

4. Add the propyl gallate and stir until dissolved.

Add the monopropylene glycol and stir to mix.

6. To a separate mixing vessel add the deionised water and with stirring add the disodium EDTA, sodium dihydrogen phosphate and disodium hydrogen phosphate in order ensuring each is fully dissolved before the next is added.

7. Add the sodium chelate and stir until fully dissolved.

8. Add the mineral premix and stir well to mix.

9. With stirring add the water phase to the solvent phase and stir until fully mixed (should be a clear dark blue solution).

1 0 10. Make up volume with monopropylene glycol and stir well to mix.

11. Package the product in appropriate packaging.

Example 2a: Formulation Type: Drench Intended Recipient Animal: Sheep, cattle, goats 1 5 Ingredient %w/v Ivermectin 0.1 Praziquantel 1.88 Tween 80 10.0 Glycerol Formal 10.0 Benzyl Alcohol Propyl Gallate 0.009 Monopropylene Glycol 40.0 Deionised water 20.0 Disodium EDTA 0.009 Sodium dihydrogen phosphate Disodium hydrogen phosphate Mineral Premix 10.0 Selenium Chelate 0.305 Monopropylene Glycol To volume 100.0 mL The mineral premix is a chelated mineral mixture of Copper, Cobalt and Zinc.

-6 Example 2b: Formulation Type: Drench Intended Recipient Animal: Sheep, cattle, goats Ingredient %w/v Abamectin 0.1 Praziquantel 1.88 Tween 80 10.0 Glycerol Formal 10.0 Benzyl Alcohol Propyl Gallate 0.009 Monopropylene Glycol 40.0 Deionised water 20.0 Disodium EDTA 0.009 1 5 Sodium dihydrogen phosphate Disodium hydrogen phosphate Mineral Premix 10.0 Selenium Chelate 0.305 Monopropylene Glycol To volume 100.0 mL The mineral premix is a chelated mineral mixture of Copper, Cobalt and Zinc.

Examples 2a and 2b are manufactured as follows: 1. To a clean dry mixing vessel add the benzyl alcohol and with stirring add the ivermectin or abamectin. Stir until completely dissolved.

2. Add the Tween 80 and glycerol formal and stir until completely dispersed.

3. Add the praziquantel while stirring and warm the solution to 50-60 0 C. Continue stirring until fully dissolved.

4. Add the propyl gallate and stir until dissolved.

Add the monopropylene glycol and stir to mix.

6. To a separate mixing vessel add the deionised water and with stirring add the disodium EDTA, sodium dihydrogen phosphate and disodium hydrogen phosphate in order ensuring each is fully dissolved before the next is added.

7. Add the sodium chelate and stir until fully dissolved.

8. Add the mineral premix and stir well to mix.

I--

-7 9. With stirring add the water phase to the solvent phase and stir until fully mixed (should be a clear dark blue solution).

Make up volume with monopropylene glycol and stir well to mix.

11. Package the product in appropriate packaging.

Example 3: Formulation Type: Drench Intended Recipient Animals: Sheep, cattle, goats Ingredient %w/v Abamectin 0.113 Praziquantel 1.88 Selenium (Na 2 Se) 0.305 Mineral Premix 10.00 Polysorbate 80 BP 5.00 Benzyl Alcohol BP 2.00 Ethyl Lactate 10.00 Potassium Sorbate 0.18 Formalin 0.20 Purified water BP 20.00 Sodium Phosphate BP 0.10 Sodium Acid Phosphate 0.90 Propylene Glycol BP to volume 100.0 mL The mineral premix is a chelated mineral mixture of Copper, Cobalt and Zinc.

2 5 Example 3 is manufactured as follows: 1. To a clean dry mixing vessel add the ethyl lactate, benzyl alcohol and Polysorbate 2. While stirring add the abamectin and praziquantel and stir until dissolved.

3. To a separate mixing vessel add the water and dissolve in the potassium sorbate.

4. Add the sodium phosphate and sodium acid phosphate and stir until fully dissolved.

5. Add the selenium and mineral premix and stir to dissolve.

6. Add the water mix to the abamectin/praziquantel mix and stir well to mix.

7. Add the formalin and stir well.

-8 8. Make up to volume with the propylene glycol.

9. Package the product in suitable container.

Examples 1, 2a, 2b and 3 produce stable solutions that are aqueous based. They may be administered at a rate of lmL/5-20kg of bodyweight of the animal every 6-8 weeks or as required.

Example 4: Formulation Type: Oral Paste Intended Recipient Animals: Horses and Companion animals 1 0 Ingredient %w/v Abamectin 0.400 Praziquantel 5.000 DiEthylene Glycol Palmito Stearate (DEGPS) 8.000 Oat Meal Flour 30.00 1 5 Sodium Metabisulfite 0.100 Sorbitol Solution (non-crystallising) 12.00 Glycerol Formal 6.000 PolyEthylene Glycol 400 6.000 Methyl Hydroxybenzoate 0.050 Propyl Hydroxybenzoate 0.005 Benzyl Alcohol 1.000 Purified Water To volume 100.0 mL Example 4 is manufactured as follows: 1. In a separate container, heat purified water to 80-850. Maintain at this temperature.

2. While mixing, add and dissolve methyl hydroxybenzoate and propyl hydroxybenzoate. Continue mixing until all has dissolved.

3. While mixing, add sorbitol solution. Maintain the temperature at 70 0

C.

4. In a separate container add glycerol formal, polyethylene glycol 400 and benzyl alcohol. Start mixing while warming to 35-40 0

C.

While mixing, add abamectin. Continue mixing until all has dissolved. Maintain temperature at 35-40 0

C.

-9 6. In the ointment tank add half the oat meal flour and the praziquantel and then start mixing. Continue mixing for 5-10 minutes then add the rest of the oat meal flour and continue mixing until a homogenous blended powder is formed.

7. While mixing the powders add the solution from step 5 in a thin stream. When all is added continue mixing until a homogenous mass is formed.

8. Melt DiEthylene Glycol Palmito Stearate (DEGPS) in a separate container. While mixing the solution from step 3, add the melted wax and continue mixing to form an homogenous emulsion. Stop heating and mix to cool to 40-45 0

C.

1 0 9. Add and dissolve sodium metabisulfite in the emulsion.

While mixing the mass from step 7, add gradually and in a thin stream the emulsion from step 9. Emulsion when added should be at 40-45°C.

11. When all is added continue mixing for 10-15 minutes descaping the walls occassionally.

1 5 12. Complete the batch to volume with purified water while mixing. Continue mixing for 30 minutes. Stop when the batch temperature is not higher than 30°C. Check the specific gravity (1.05-1.09).

13. Homogenise the batch. When completed the batch is in the form of a smooth paste, free from lumps or grittiness, beige in colour and has a pleasant characteristic odour.

14. Package in paste syringes.

In example 4 oat meal flour is used as a solid carrier. Other examples of solid carriers that could be used are methancel or xanthan gum.

Example 4 produces a spreadable, viscous paste which may be administered to an animal as an oral paste at the rate of lmL/5-20 kg of bodyweight of the animal every 6-8 weeks or as required. The formulation is aqueous based.

10 Example Formulation Type: Drench Intended Recipient Animals: All farm animals Ingredient %w/v Abamectin 0.100 Praziquantel 1.880 Benzyl Alcohol 10.00 Soyabean oil To volume 1 0 100.0 mL Example 5 is preferably manufactured as follows: 1. To a clean dry mixing vessel add the Benzyl Alcohol, and while stirring add the Abamectin and Praziquantel. Continue to stir until completely dissolved.

2. Make up to volume with the Soyabean Oil and stir well to mix.

1 5 3. Package the product in suitable packaging.

Example 5 produces a solution that is oil based. It may be administered at a rate of lmL/5-20kg of bodyweight of the animal every 6-8 weeks or as required.

Example 6: Formulation Type: Injectable Intended Recipient Animals: All farm animals Ingredient %w/v Abamectin 1.22 Praziquantel 15.0 Glycerol Formal 60.0 Monopropylene Glycol To volume 100.0 mL Example 6 is manufactured as follows: 1. To a clean dry mixing vessel add the glycerol formal and while stirring add the abamectin and praziquantel. Continue to stir until dissolved.

2. Make up to volume with monopropylene glycol and stir well.

11 3. Sterilise product by suitable filtration and pack under sterile conditions into suitable injection bottles.

Example 6 produces a solution that is suitable for injection. It may be administered at a rate of lmL/5-20kg of bodyweight of the animal every 6-8 weeks or as required.

Example 7: Formulation Type: Injection or Drench Intended Recipient Animals: All farm animals Ingredient %w/v Abamectin 1.22 Praziquantel 15.0 N-Methyl-2-Pyrolidone 60.0 Sesame Oil To volume 100.0 mL 1 5 Example 7 is manufactured as follows: 1. To a clean dry mixing vessel add the glycerol formal and while stirring add the abamectin and praziquantel. Continue to stir until dissolved.

2. Make up to volume with sesame oil and stir well.

3. Package product under sterile conditions into suitable injection bottles or in suitable containers for a drench formulation.

Example 7 produces an oil based solution that is suitable for administration as an injection or a drench. It may be administered at a rate of lmL/5-20kg of bodyweight of the animal every 6-8 weeks or as required.

The compositions of the invention are stable and have been shown to be non-toxic to animals.

STABILITY

Example 3 Stability Trial A solution according to example 3 was prepared and tested for stability. The solution was stored at ambient temperature in a black high density polyethylene container with a black high density polyethylene cap.

12 A variety of tests were performed on the composition initially, and then at 3 months, 6 months and one year. The results are set out in Table 1.

TABLE 1: Stability of Example 3 Test Initial 3 Months 6 Months 1 Year Appearance Clear, blue liquid Clear, blue Clear, blue Clear, blue liquid liquid liquid Appearance after Okay Okay Okay Okay inversion Density at 20°C 1.062 1.063 1.065 1.067 (g/mL) Viscosity at 14 14 14 14 0 C Ford #4 Cup (Seconds) Bottle condition Okay Okay Okay Okay pH 6.7 6.4 5.8 5.8 Praziquantel 18.9 17.9 18.9:18.9* 18.9 (g/L) Abamectin 1.09 1.00 1.03:1.04* 0.95

MINERAL

PREMIX

-Copper 2.12 2.19 2.24 2.23 Cobalt 0.24 0.21 0.20:0.21* 0.20:0.20 Zinc 0.61 0.60 0.58:0.56* 0.63 Selenium 0.45 0.49 0.48 0.50:0.50 [*Repeat assays carried out where first assay result was in doubt] There was no loss of stability of the composition over the trial period.

Copper, cobalt and zinc are included in the mineral premix of example 3. Selenium is added separately to the composition.

13 Example 4 Stability Trial A spreadable paste according to example 4 was prepared and tested for stability at and at 40°C. The paste was stored in a plastic syringe inside a carton.

The amount of the active ingredients was measured initially, and then at one month, three months and six months. The results are set out below in Table 2 and Table 3.

TABLE 2: Stability of Example 4 at Initial 1 Month 3 Months 6 Months Abamectin 3.5 3.7 3.6 3.6 (g/kg) Total Avermectin 3.7 3.9 3.8 3.8 (g/kg) Praziquantel 50 50 46 48 (g/kg) [Differences in Abamectin and Total Avermectin concentrations over the trial period was within the margin of error for the trial] 1 0 TABLE 3: Stability of Example 4 at 40 0

C

Initial 1 Month 3 Months 6 Months Abamectin 3.5 3.4 3.1 3.4 (g/kg) Total Avermectin 3.7 3.6 3.3 3.7 (g/kg) Praziquantel 50 48 48 49 (g/kg) [Differences in Abamectin and Total Avermectin concentrations over the trial period was within the margin of error for the trial]

EFFICACY

The efficacy of example 3 (Speedwell P Mineral Drench for Sheep) and example 3 1 5 without praziquantel (Speedwell Mineral Drench for Sheep) in the control and treatment of naturally occurring infection with common pathogenic nematodes and cestodes was assessed against the commercially available product Ivomec Liquid for Sheep and Goats (Merck Sharp Dohme).

14 The study and interpretation of the raw data was undertaken in accordance with the World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines.

Abamectin stimulates the release of a neurotransmitter, gamma aminobuteryic acid (GABA) from the nerve endings and enhances its binding to GABA receptors at the nerve junctions. This action interrupts nerve impulses and leads to paralysis and death. It has no effect against cestodes, trematodes nor the mammalian peripheral nervous system.

Praziquantel inhibits cestode carbohydrate metabolism.

Allbcation of Test Animals 1 0 Thirty -two clinically healthy Romney hoggets were used. The hoggets were selected on the basis of similar weight and overall body condition. No other medication was administered during the study period.

The hoggets were assigned randomly, on the basis of faecal egg count (FEC) and egg identification, to one of the following groups: Group 1: Control (untreated) Group 2: Positive Control (T1) Group 3: Test (T2) Group 4: Test (T3) The hoggets were maintained together throughout the trial.

15 Treatment Group 1: No treatment Group 2: Hoggets were treated in accordance with Ivomec Batch 6639105 Exp. 01/95 label, ie 1 mL per 4 kg bodyweight (providing a dose of 200 (g Ivermectin per kg bodyweight) T1 Group 3: Hoggets were treated with 1 mL Speedwell Mineral Drench Batch XIV-12 per 5 kg bodyweight (providing 200 (g Abamectin per kg bodyweight) T2 Group 4: Hoggets were treated with 1 mL Speedwell P Mineral Drench Batch XIV-18 per 5 kg bodyweight (providing 200 (g Abamectin and 3.76 mg Praziquantel per kg bodyweight) T3 Trial Activity and Design Day -1 A group of 32 hoggets on the basis of similarity of bodyweight, overall body condition and health status were selected. A faecal egg count on all animals was carried out.

Day 0 On the basis of faecal egg count allocation was made randomly 8 animals to each group.

Day 1 Treatment of hoggets as follows: Group 1: No treatment Group 2: Ivomec treatment T1 Group 3: Speedwell Mineral Drench Treatment T2 Group 4: Speedwell P Mineral Drench Treatment T3 Day 9 Faecal egg count on all hoggets.

Live weights taken.

Day 12 Hoggets slaughtered.

Removal of abomasum, and small and large intestines. Worms recovered, identified and counted.

Lungs were also examined for the presence of lungworm.

16 Parameters Parameters for evaluation of Speedwell Mineral Drench and Speedwell P Mineral Drench efficacy and comparison with Ivomec treated and control groups were body weight, total egg count and total abomasal, intestine and lung worm count.

Assessment Assessment was made by the clinical investigator. On the basis of satisfactory egg count on Day 9 total abomasal, intestine and lung counts proceeded.

Parasitology Analysis 1 0 Target parasite species were Haemonchus, Ostertagia, Trichostrongulus, Cooperia, Nematodirus, Oesophagostomum, Chabertis and Monezia expansa.

Total faecal egg count and necropsy procedures were performed by New Zealand Ministry of Agriculture and Fisheries Ruakura Animal Health Laboratory, Hamilton, New Zealand using approved and consistent methods and blind evaluation.

Results The results of the trial are shown in tables 4 7 below.

Key for Tables 4-7: Strong. Strongulus Nema. Nematodirus Haem. Haemonchus Ostert. Ostertagia Trich. Trichostrongulus Coop. Cooperia Scholex. Heads of Monezia expansa Seg. Mis Segments (tape-like) of M. Expansa measured as millilitres TABLE 4: Group I C"rl He TsarmmI TAG No. WT. DOSE START POST DOSE 12 DAY CRICAL SLAUGiTR WORM COUNTS

MONIA

mI. Strong. Nema. Suom. Ncrm. Harm. Ownf. Trich. Nema. Tiich. Coop. Scholex Sesmis 39 20 2100 1300 t o 2800 23200 5200 36 22 3100 300 1. 300 1900 6000 700 7 22 3100 50 2450 300 2200 200 14500 2800 4 24 2950 1650 0oo 700 13000 30000 4200 28 23 2300 3050 600 8800 20800 1600 2 23 2250 2300 2500 t00 9200 2000 4 39 28 700 800 200 10200 14400 2600 31 22 3150 2700 200 2800 7200 800 3 MEAN 2681 6.25 1318 12.3 275 5825 37.5 16912 2487 1.6 7.25 TABLE 5: Group 2- IVOMEC Cr1) TAG No. War. DOSE START POST DOSE 12 DAY CRICAL SLAUGHTER WORM COUNTS

MONIEZIA

mI. Ncma. Strong. Nam. Hm. Oseu. Trich. Hems. Trih. coop, Scholex Sei mix 6 21 5.0 3350 Is i8 4-5 3050 33 22 5.5 2850 I I 24 6.0 2350 42 20 5.0 2100 17 26 6.5 2250 26 24 6.0 1150 3 I 22 5.5 600 32 8 2 MEAN 2212.5 6.25 1 2. 4.25 PERCNTAGE() 99.9 99.9 99.9 9.9 99.9 f 9.9 99.9 99.9 6.25 41.3 TABLE 6: Group 3-SpedweE MbMel Dreime C172) TAO No. WOT. DOSE START POST DOSE I DAY CRITICAL SLAUOHI-TER WORM COUNTS MONIEA mi. summi. Ncma. Sums. Ncm*. Hacm. Osiet. Trich. Ncnn. Trich. Crip. Sdrolex.

41 It 3.5 6900 50

I

24 5.0 3300 50 -3 3 3 22 4.5 3050 7 13 12 22 4.5 2900 3. 3 IS 24 5.0 2350 14 4 21 22 4.5 4550 5 2 38 22 4.5 1800 2 16 26 5.0 S150 I. MEAN 2446 12.5 4.37 19.37 LRCEAO E 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9 TABLE 7: Group 4- Speed well P Mineral Drenh 13) TAO No. WGT. DOSE START POST DOSE 12 DAY CRITICALSLAUGHTER WORM COUNTS MONIEZIA S Neva. Stanx. Nema. Hacm Ole. Trck. Kern. Trick. COPP. Scholex Ses.nb 4 22 4.5 5800 37 23 4.5 3000 50 34 22 4.5 2800 9 22 4.5 2750 1600 13 20 4.0 2050 23 27 5.5 1950 26 5.0 650 32 24 5.0 700 MEAN 2462.5 6.25 200 PRCENTAGE() 84.1 99.9 99.9 99 99.9 99.9 99.9 99.9 99.9 99.9 19 The data was analysed comparing treatment group means and in accordance with WAAVP guidelines.

The study compared the efficacies of Speedwell Mineral Drench Batch XIV-12 and Speedwell P Mineral Drench Batch XIV-18 based on pre- and post dosing FEC's and 12 day slaughter worm counts. When compared with Ivomec Batch 6639105 both products demonstrated 99.9% efficacy against nematodes when compared with the control group.

Against Monezia expansa only Speedwell P Mineral Drench (containing praziquantel) demonstrated efficacy at 99.9%. Both Speedwell Mineral Drench and Ivomec were 1 0 ineffective.

INDUSTRIAL APPLICATION The veterinary compositions of the invention have been shown to be stable, non-toxic and effective in the treatment of endo- and ectoparasites in animals including but not limited to sheep, cattle, goats, and horses.

ADVANTAGES

It is advantageous to combine two or more anthelmintics with different activity in one composition to obtain a broad spectrum activity.

It is also advantageous to the user as only one treatment is needed against a number of parasites instead of two or more different treatments. This reduces the amount of time spent treating animals and therefore reduces stress to the animals themselves.

VARIATIONS

Although the above examples have concentrated on the use of praziquantel combined with abamectin or ivermectin, any other compound of the avermectin group could also be used.

In forming the compositions of the invention the active anthelmintic ingredients are dissolved in a solvent. In some instances it is preferred to thicken the resulting solution by absorbing it onto a solid carrier. These thickened solutions are also within the scope of the invention.

Finally, it will be appreciated that various other alterations and modifications may be made to the foregoing without departing from the scope of this invention.

Claims (2)

1. A viscous oral anthelmintic paste suitable for oral administration to horses containing an effective amount of abamectin, an effective amount of praziquantel and a paste like carrier including an organic solvent selected from the group consisting of glycerol formal, ethyl lactate, benzyl alcohol and N-methyl-2- pyrrolidone and the like, and a solid carrier.

2. A viscous oral anthelmintic paste suitable for oral administration to horses according to claim 1 wherein the organic solvent is glycerol formed together with 1 0 PolyEthylene Glycol, and wherein the solid carrier is selected from the group comprising oat meal flour, methancel, and xanthan gum. A viscous oral anthelmintic paste suitable for oral administration to horses according to claim 2 and containing in addition DiEthylene Glycol Palmito Stearate, and Sorbitol Solution. 1 5 Dated this 20th day of August 1999 ASHMONT HOLDINGS LIMITED By their Patent Attorneys A.P.T. Patent and Trade Mark Attorneys