AU695582B2

AU695582B2 - Anthelmintic formulations

Info

Publication number: AU695582B2
Application number: AU74694/94A
Authority: AU
Inventors: Colin Manson Harvey
Original assignee: Ashmont Holdings Ltd
Current assignee: Merial Ltd
Priority date: 1993-08-24
Filing date: 1994-08-22
Publication date: 1998-08-13
Anticipated expiration: 2014-08-22
Also published as: EP0724437A4; NZ248486A; AU7469494A; EP0724437A1; ZA946195B; WO1995005812A1

Description

WO 95/05812 PCT/NZ94/00084 -1- ANTHELMINTIC FORMULATIONS

FIELD

This invention relates to veterinary compositions for the treatment of helminthiasis in warm-blooded animals, more particularly cattle, sheep, goats, and other domesticated herbivores.

BACKGROUND

Helminthiasis is a widely occurring disease in farmed animals. It commonly causes clinical disease and has significant adverse economic effects on farming economies when present at subclinical levels. Over the past twenty-five years a number of initially successful anthelmintic agents, with relatively specific effects on the metabolism of smaller or larger groups of endoparasites have been discovered, trialled, and used successfully to control helminthiasis on farms. Various groups of compounds have a greater or lesser spectrum of activity that is to say they are able to destroy a wider or smaller range of parasite. For example, the widely used "ivermectin" is active against parasitic roundworms and also against some ectoparasites, yet it is inactive against tapeworms because of a difference in their biochemical constitution. "Triclabendazole" is active only against the liver fluke Fasciola hepatica.

The drug closantel is a useful anthelmintic active agent that gives control over a range of internal parasites including liverfluke in cattle and sheep. For this reason it has been used in aqueous suspension in combination with other anthelmintics such as albendazole and mebendazole.

This invention is based on the surprising discovery that an anthelmintic solution can be prepared from a combination of closantel and an avermectin or milbemycin like anthelmintic, for example ivermectin, moxidectin and doramectin. Such solutions have advantages in ease of use and may also be used by injection. Glycol based solvents such as polyethylene glycol and propylene glycol are able to dissolve both compounds to produce a stable formulation. Such formulations may also be dispersed in water.

The milbemycins are described in the 11th Edition of the Merck index as a family of novel macrolide antibiotics with Milbemycin D in particular being used as an h p'i, ~g~

V

*"t

'C

2 anthelmintic. The avermectins are described in the 11 th Edition of the Merck index as a group of broad-spectrum antiparasitic compounds which are derivatives of pentacyclic 16-membered lactones related to the milbemycins. The most well known of these avermectins is ivermectin which is a semi-synthetic derivative of abamectin (one of the avermectins).

OBJECT

It is an object of this invention to provide novel veterinary compositions having anthelmintic activity.

STATEMENT OF INVENTION In one aspect of the invention comprises a stable anthelmintic formulation comprising glycerol formal together with an effective amount of closantel and an effective amount of one or more anthelmintics chosen from the group consisting of the class of avermectins and the class of milbemycins.

In a further aspect the invention provides a method for treating helminthiasis in animals with compositions comprising an effective amount of the anthhcI'.nlntic closantel together with an glycol based solvent and an effective amount of at least one other anthelmintic.

Preferably the other anthelmintic is chosen from the group comprising the avermectins or milbemycins. Such a group includes moxidectin, ivermectin, doramectin, Milbemycin D, as well as other milbemycins.

Preferably the closantel and other anthelmintic is dissolved in a mixture selected from at least two of: propylene glycol, polyethylene glycol, glycerol formal and water.

I

WI-rru- -2a Preferably the compositions of the present invention are used by injection. They may also include trace elements and/or vitamins.

Preferably the closantel and other anthelmintic may be each present at from 0.5 to 15% w/v respectively, and more preferably the closantel is present at from 1 to 2% w/v.

In other aspect the invention provides a method of treating animals for helminthiasis by injecting a composition as previously described at the rate of of the animal's live weight (different dose rates and percentages of active ingredients will become apparent from the examples).

0o go 0 00 *eo o eg* o eg i-Ii j WO 95/05812 PCT/NZ94/00084 -3-

EXAMPLES

These and other aspects of the invention will be apparent from the following description, which is given by way of example only.

Examnle 1: 0 w/v Closantel 3.75 Ivermectin 0.08 Propylene glycol to 100.00 Polyethylene glycol 20.00 This formulation is suitable for use as an oral drench for sheep which would offer control of parasites resistant to older anthelmintics such as the benzimidazoles and levamisole as well as controlling adult liverfluke.

Esamil: I al Closantel 3.75 Moxidectin 0.10 Propylene glycol 40.00 Polyethylene glycol 20.00 Water to 100.00 This formulation is suitable for use as an injection for sheep and cattle. It gives the advantage of longer action of moxidectin combined with activity against liverfluke.

Examnlez: 3Lyv Abamectin 1.13 Sodium Closantel 1.30 Glycerol formal 40.00 Water 30.00 Sodium Selenate 1.20 Tween 80 20.00 Benzyl Alcohol 1.00 SGlycerol formal (ii) to 100.00 P-A ~IC~r~C~ WO 95/05812 PCT/NZ94/00084 -4- This is an injectable composition containing selenium.

Preparation Example To a clean dry mixing vessel, add the glycerol formal and Tween 80. With stirring, add the abamectin and sodium closantel, and heat to about 60" 70' C with continued stirring until dissolved. Dissolve the sodium selenate in water and add to the batch while stirring. Allow to cool to room temperature and add the benzyl alcohol, stirring well to disperse. Make up to 100% volume with glycerol formal (ii).

Trial solutions of Example 3 were found to be stable overnight at 2*C, 21"C and 37°C with the active ingredients remaining soluble at all temperatures.

Use This injectable formulation can be applied to cattle at a dose rate of lmL/50kg of live weight, to provide the animal with 2.5mg/kg of closantel whilst at the same time supplying an effective dose of abamectin and a trace element such as selenium.

Example 4: Dose rate g/L Abamectin Closantel 125 Glycerol formal 400 PEG 400 600 Benzyl alcohol This provides another injectable formulation without the trace element by using a combination of polyethylene glycol (PEG 400) and glycerol formal.

Examples 5 7 show other injectable compositions containing different amounts of closantel to be used at a formulation dose rate of 1 mL/25kg of animal live weight.

*1 WO 95/05812 PCT/NZ,94/00084 EzawDjC S Dose rate Abamnectin Closantel Glycerol formal PEG 400 Benzyl alcohol 911, 187.5 400 600 Dose rate Abamnectin Closantel Glycerol formal PEG 400 Benzyl alcohol 62.5 400 600 Dose rate Abamectin Closantel Glycerol formal PEG 400 Benzyl alcohol 125 400 600

I

VARIATIONS

In addition to the combination of closantel and an avermectin or milbemnycin the compositions of this invention can contain trace elements. Example 3 describes a composition containing selenium. Other trace elements or vitamins may be included.

I

k

L,

I

WO 95/05812 PCT/NZ94/00084 -6- Examples of trace elements include copper, cobalt, iodine, zinc or the like. The vitamins may be for example vitamins A, B, D, or E.

ADVANTAGES

The compositions of this invention are stable and safe to use. The glycol based solvents used in this invention are non-irritant solvents and can safely be used in injectable compositions. The injectable compositions are particularly suited to the control of helminthiasis in cattle.

i~.

i-

Claims

1. A stable anthelmintic formulation comprising glycerol formal together with an effective amount of closantel and an effective amount of one or more anthelmintics chosen from the group consisting of the class of avermectins and the class of milbemycins.

2. A stable anthelmintic formulation as claimed in claim 1, wherein the avermectins and the milbemycins are selected from the group consisting of abamectin, ivermectin, moxidectin, doramectin and Milbemycin D.

3. A stable anthelmintic formulation as claimed in claim 2, wherein the closantel and other anthelmintic are each present at from 0.5% to 15% w/v respectively.

4. A stable anthelmintic formulation as claimed in claim 1 substantially as herein described with reference to the examples. A process for preparation of a stable anthelmintic formulation as claimed in claim 1 Ssubstantially as herein described with reference to the examples. S6. An injectable formulation comprising a stable anthelmintic formulation as claimed in any one of claims 1 to [z 7. A method for treating helminthiasis in animals 25 (other than humans) by injecting a stable formulation as claimed in claim 6 at the rate of lmL/25kg to lmL/50kg of the animal's live weight. DATED this 29th day of June 1998 ASHMONT HOLDINGS LIMITED By their Patent Attorneys CULLEN CO. ~II INTERNATIONAL SEARCH REPORT International application No. PCT/NZ 94/00084 A. CLASSIFICATION OF SUBJECT MATTER Int. C1.

5 A61K 31/16, 31/365 According to International Patent Classification (IPC) or to both national classification and IPC B. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbo,. A61K 31/16 Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched AU: IPC as above Electronic data base consulted during the international search (name of data base, and where practicable, search terms used) DERWENT: Closantel or (Diodobenzamide and Antihelinth:) and A61K C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to Claim No. A AU,A,64533/90 (BANSTEAD ENTERPRISES LTD) 18 April 1991 (18.04.91) A US,A,4470979 (VAN GESTEL) 11 September 1984 (11.09.84) A Derwent Abstract Accession No. 94-014506/02 Class B05, SU,A,1782593, (IVAN AGRIC RES INST) 23 December 1992) (23.12.92). S Further documents are listed See patent family annex. in the continuation of Box C. Special categories of cited documents later document published after the international filing date or priority date and not in conflict document definin the eneral state of the art which is with the application but cited to understand the not considered to be ofparticular relevance principle or theory underlying the invention earlier document but published on or after the document of particular relevance; the claimed international filing date invention cannot be considered novel or cannot be document which may throw doubts on priority claim(s) considered to involve an inventive step when the or which is cited to establish the publication date c document is taken alone another citation or other special reason (as specified) document of particular relevance; the claimed document referring to an oral disclosure, use, invention cannot be considered to involve an exhibition or other means inventive step when the document is combined document published prior to the international filing date with one or more other such documents, such but later than ihe priority date claimed combination being obvious to a person skilled in the art document member of the same patent family Date of the actual completion of the international search Date of mailing of the international search report 17 November 1994 (17.11.94) -1 E' C4 C 1- Name and mailing address of the ISA/AU Authorized officer AUSTRALIAN INDUSTRIAL PROPERTY ORGANISATION PO BOX 200 WODEN ACT 2606 AUSTRALIA J P PULVIRENTI Facsimile No. 06 2853929 'Telephone No. (06) 2832253 Form PCT/ISA/210 (continuation of first sheet (July 1992) coplew r i INTERNATIONAL SEARCH REPORT Information on patent family membe International application No. PCT/NZ 94/00084 Ii ii This Annex lists the known publication level patent family members relating to the patent documents cited in the above-mentioned international search report. The Australian Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent Document Cited in Search Patent Family Member Report AU,A, 64533/90 EP 427582-A ZA 9008165-A US 5169846-A NZ 235647-A US 4470979 CA 1217133-A END OF ANNEX Form PCT/ISA/210(patent family annex)(July 1992) coplew