AU2003258756B8 - Oleaginous oral antiparasitic compositions - Google Patents

Abstract

An oily composition (I) comprises: (a) an oil vehicle; (b) at least one macrocyclic lactone dissolved in (a); and (c) at least one of closantel and its salts suspended in (a).

Description

1 IN THE MATTER OF an Australian Application corresponding to PCT Application PCT/FR03/01432 RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, hereby solemnly and sincerely declares that, to the best of its knowledge and belief, the following document, prepared by one of its translators competent in the art and conversant with the English and French languages, is a true and correct translation of the PCT Application filed under No. PCT/FR03/01432.

Date: 27 October 2004 S. ANTHONY Director For and on behalf of RWS Group Ltd (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (43) International publication date 4 December 2003 (04.12.2003) PCT (10) International publication number WO 03/099259 Al (51) International patent classification 7 A61K 9/10, 31/7048, 31/609, 47/44 (A61K 31/7048, 31:609) (21) International application number: (22) International filing date: 1 PCT/FR03/01432 2 May 2003 (12.05.2003) Language of filing: French (26) Language of publication: French Data relating to the priority: 02/05,899 14 May 2002 (14.05.2002) FR (71) Applicants (for all designated States except US): VIRBAC S.A. [FR/FR]; 16re Avenue 2065m F-06516 Carros JANSSEN PHARMACEUTICA NV [BE/BE]; Turnhoutseweg 30, B-2340 Beerse (BE).

(72) Inventors; and Inventors/Applicants (US only): DERRIEU, Guy [FR/FR]; Le Riviera Pare, 33, chemin du Lautin, F-06800 cagnes-sur- Mer DELHOM, Nathalie [FR/FR]; Villa "Les Vergers", 145, avenue des Poilus, F-06140 Vence DE SPIEGELEER, Bart [BE/BE]; Keizer Karelstraat 228, B-9000 Ghent (BE).

(74) Representatives: ORES, Beatrice etc.; Cabinet Ores, 36, rue de St-Petersbourg, F-75008 Paris (FR).

(81) Designated states (national): AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NI, NO, NZ, OM, PH, PL, PT, RO, RU, SC, SD, SE, SG, SK, SL, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, YU, ZA, ZM, ZW.

(84) Designated states (regional): ARIPO Patent (GH, GM, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZM, ZW), Eurasian Patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European Patent (AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IT, LU, MC, NL, PT, RO, SE, SI, SK, TR), OAPI Patent (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, ML, MR, NE, SN, TD, TG).

Published: S With International Search Report.

Before the expiration of the time limit for amending the claims and to be republished in the event of receipt of amendments.

For an explanation of the two-letter codes and the other abbreviations, reference is made to the explanations ("Guidance Notes on Codes and Abbreviations") at the beginning of each regular edition of the PCT Gazette.

As printed (54) Title: OLEAGINOUS ORAL ANTIPARASITIC COMPOSITIONS (54) Titre: COMPOSITIONS ORALES -HULEUSES ANTIPARASITAIRES S(57) Abstract: The invention relates to an oleaginous composition comprising: an oleaginous vehicle, at least one compound chosen Z* from amongst the macrocyclic laclones in solution in the oleaginous vehicle and at least one complound chosen from closantel or one of the salts thereof, suspended in said oleaginous vehicle. Said composition is used for the preparation of a medicament for the prevention and/or treatment of parasites.

(57) Abrg6 L'invention concerne une composition huileuse comprenant: un vdhicule huileux, au moins un compose choisi parmi les lactones macro cycliques, en solution dans le v6hicule huileux au moins un compost choisi parmi le closantel ou Ftun de ses sels, en suspension dans ledit vehicule huileux. Une telle composition esl utilise pour la preparation d'un medicament destine a la pr6vention ellou au irailernent de parasite.

,L

WO 03/099259 PCT/FR03/01432 OLEAGINOUS ORAL ANTIPARASITIC COMPOSITIONS The present invention relates to novel compositions, in particular compositions intended for oral administration for veterinary use, consisting of an oleaginous vehicle and of at least one compound chosen from macrocyclic lactones, in solution, in combination with at least one compound chosen from closantel and the salts thereof, in suspension, these compositions being, moreover, physically and chemically stable.

Veterinary antiparasitic compositions must be suitable for controlling the pathogenic endoparasites and ectoparasites that are encountered in livestock and related animals, but also in zoo animals, laboratory animals, animals for experimentation and pets. As particular examples, mention may be made of cattle, members of the horse family, the ovine race, members of the goat family, pigs, or else members of the camel family, donkeys, deer, reindeer, buffalo, poultry, ostriches, or domestic cats or dogs.

The pathogenic parasites include plathelminthes such as cestodes and trematodes, nemathelminthes such as nematodes, and acanthocephalans, or else arthropods.

These parasites are very widespread in the animal kingdom. Parasitic development requires passage through various stages, egg-larval-immature-adult stages, and penetration into various tissues of the hosts, resulting in clinical symptoms of the parasitic disease. During both the clinical and subclinical phases, these parasitic infestations create considerable problems, especially in young animals which are often immunodeficient, not forgetting the possible transmission of the parasites to humans. It is therefore necessary to have treatments for taking care of the animals infected with parasites, but also for preventing infestations in healthy animals. All these I L -2diseases have negative zootechnic consequences on animals for breeding, such as a reduction in carcass yields, or a decrease in the production of milk, of eggs, wool, skins and hides, and they sometimes lead to animal losses.

Existing antiparasitic active principles have activities that are different with respect to the parasites envisioned. Thus, it is desirable to have compositions which combine various active principles that are effective against various parasites which may infest the same animal, so as to broaden the spectrum of activity of the composition with respect to a composition which contains only one active principle.

It is, for example, advantageous to be able to have an oral composition that combines at least one compound having nematodicidal action with at least one compound having trematodicidal action in the case of concomitant infestations of the animal with nematode (for example of the genus Cooperia spp. or Haemonchus spp. or Dictyocaulus spp.) and fluke (for example Fasciola hepatica) pathogenic parasites. The compositions are then active against all or against various stages of the development of a large number of parasites.

Moreover, the individual spectra of action of each of the active principles combined can be superimposed, thus enabling the composition to be more effective in the treatment of parasites sensitive all at once to the various active principles. By controlling pathogenic endoparasites and ectoparasites, the invention is to prevent or reduce parasitic disease, mortality and yield decreases (for example in meat, milk, wool, egg production, etc.), such that the use of the compositions envisioned enables a simpler and more economical management of the animals. It is, however, important for the use of the compositions to be practical for the individual who administers the treatment.

3 In this respect, drinkable oral compositions are particularly suitable for the administration of drug treatments, in particular in sheep and cattle. Such a composition should be stable and easy to store, to transport and to administer to the animals, in particular it should be well accepted by the animal.

Thus, in the veterinary field, there exists a need for effective treatments having a broad spectrum of activity, which are practical to handle and to administer to the animal, which are well accepted by the animal, and which are sufficiently stable to allow successful storage of the composition for a period of at least two years.

In this context, it is very advantageous to have a composition that combines a macrocyclic lactone such as an avermectin (for instance ivermectin), the nematodicidal (or antiparasitic) properties of which have been very widely used for a long time in the veterinary field, and closantel or a salt thereof, the flukicidal properties of which, by virtue of the activity against trematodes, have also been very widely used in the veterinary field. It must be possible for this composition to be readily administered to animals orally and it must be stable.

It is also important for the composition to be well tolerated by the animal and not to be toxic to the animal, to the individual who administers the treatment or to the environment. Thus, the intention will be to decrease as much as possible the doses of active principle administered, while at the same time conserving satisfactory effectiveness, such that the treatment is substantially safe for the animal and the impact on the environment is as small as possible. It is in fact known that antiparasitic active principles can be excreted into the environment, either in the native state or in the form of degradation products 4 derived from the treated animal's metabolism. For example, the feces of grazing cattle can be dispersed in pastures and crops and can result in the destruction of useful organisms that are in soils. For a given active agent, the higher the dose administered to the animal, the greater, in general, the amounts of the active principle and/or of its metabolites that are excreted.

It is known that macrocyclic lactones, such as ivermectin for example, have negative effects on the environment, given mainly the faecal excretion of this family of molecules and of its metabolites, its high antiparasitic potency and its great persistence of activity in the organism of a treated animal. Many organisms, or even microorganisms, but especially insects that live in the soil, may be destroyed by these compounds over a long period. It is therefore very important to take care that the amounts of these compounds or of their metabolites that are excreted into the environment are as low as possible. It is, moreover, known that closantel or salts thereof, which are very widely used in the veterinary field, are substantially excreted in the feces. Thus, a composition containing the two types of active principles will be liable to have, a priori a negative impact on the environment.

Thus, there exists in the veterinary field a need for effective treatments with a broad spectrum of activity, and increased safety for use with respect to the animal and the environment that must be satisfied.

Avermectins can be administered to mammals orally or parenterally. Aqueous formulations or organic formulations that are hydrophilic in nature are often used to administer avermectins. Moreover, it is known that they are generally unstable and relatively insoluble, in particular in water. However, for oral 5 administration of a medicine, aqueous formulations are generally preferred since they have a better taste, are accepted better by animals and are less expensive than nonaqueous formulations. Thus, considerable efforts have been made to dissolve avermectins in aqueous formulations using, for example, various surfactants as described in US patent 4,389,397. However, due to the insolubility and instability of avermectins in aqueous formulations, nonaqueous formulations remain desired.

However, the nonaqueous formulations which have been developed to date for parenteral administrations are not generally suitable for oral administration. For example, US patent 4,853,372 teaches formulations comprising ivermectin dissolved in a vehicle based on propylene glycol and glycerol formal. Such compositions can cause severe irritations in animals if they are administered orally since propylene glycol is known to be responsible for ataxia and hemoglobinuria in certain animals such as sheep.

The solubility of ivermectin in organic solvents is variable and depends on the solvent used.

Patent WO 97/26895 teaches, for example, that avermectins have satisfactory solubility in Nmethylpyrrolidone or 2-pyrrolidone and mixtures thereof. They are solvents that are suitable for ivermectin formulations intended for administration by intramuscular injection, subcutaneous injection, topical application, stomach intubation and drinkable oral administration. The document presents in particular examples of formulations for oral administration comprising, as vehicle, 5% of Nmethylpyrrolidone, 20% of propylene glycol, 10% of polysorbate 80, 1.5% of benzyl alcohol, and the remainder being water more than 50% v/v of water). Such compositions are presented as having improved stability. However, no quantitative measurement of the stability is provided.

6 US patent 5,756,454 teaches nonaqueous drinkable compositions containing avermectin compounds and containing from 30 to 45% of an oil and from 50 to of a fatty acid ester in which the avermectin compound is first dissolved. The fatty acid ester increases the solubility of the avermectin compound in the composition and makes it possible to adjust the viscosity. The composition also contains an oil-soluble antioxidant (0.01 to the effect of which is to prevent degradation of the active principle and to improve the stability of the formulation. No quantitative measurement of the stability of the composition is, however, indicated.

Patent application EP 0 617 892 describes the combination of an antibiotic and of an anthelmintic as an antiparasitic agent. The activity observed for this combination is sufficiently strong to enable the total amount of chemical products used to be reduced. Such compositions are presented as being stable for many years. The antibiotic is preferably ivermectin and the anthelmintic is preferably closantel. That document gives examples of compounds in organic or aqueous medium which can be administered orally. It also mentions the formulation in the form of ointments, which presumes the presence of fatty substances and it indicates that the compositions are possibly stable for several years.

The very considerable inter-animal variation with ivermectin administration has been demonstrated by S.E. Marriner et al., Vet. Pharmacol. Ther., 175-179) and confirmed by Q.A. McKellar et al., (Vet.

Parasitology, 39, 1/2, 123-136,1991).

The applicant has shown that, unexpectedly, a composition based on a macrocyclic lactone and on closantel and/or salts thereof in an oleaginous vehicle 7 in which the macrocyclic lactone is in solution and the closantel and/or salts thereof is in suspension, firstly, exhibits good acceptability by the animals when it is administered orally and, secondly, has both a physical and chemical stability that is greater than that of an oleaginous composition in which the closantel, and/or salts thereof, is in solution.

Finally, such a composition exhibits improved bioavailability of the macrocyclic lactone compared with the bioavailability of the same macrocyclic lactone when it is used in oral compositions in an organic and/or aqueous solvent, such as the compositions described in the literature, in particular the commercial oral compositions used alone and under the same conditions. It also exhibits improved bioavailability compared with the bioavailability of the same macrocyclic lactone when it is formulated in an organic oral composition in combination with closantel or salts thereof. In addition, the oleaginous vehicle is well accepted by the animal when it is administered orally. This oleaginous vehicle makes it possible to obtain improved bioavailability of the macrocyclic lactone compared with the same combination of active principles in an organic solvent, and the undissolved state of the closantel in the oleaginous vehicle improves the stability of the composition and of the active principles that it contains.

The bioavailability is defined as the fraction of the amount of active compound that is absorbed by an organism from a composition that arrives in the general circulation, and by the rate at which the phenomenon occurs. This fraction of the dose absorbed, represented diagrammatically by a curve relating the concentration and the amount absorbed per blood volume as a function of time, is defined, inter alia, by two parameters: the Cmax, maximum plasma concentration, which represents a peak on the plotted curve, and by the AUC or "area under the curve" for the plasma. As a general rule, the 8 bioavailability, represented in particular by the maximum plasma concentration, is not a single value but a value which falls within a range of concentrations.

This range of concentrations is defined, in terms of its lower limit and in terms of its upper limit, respectively, by the smallest known value and by the largest known value for the maximum plasma concentration.

The term "improved bioavailability" should be understood to mean, inter alia, that the value of the maximum plasma concentration falls within a range of concentrations that is very much narrower than the known range. The smaller variation in the Cmax obtained for the compositions according to the invention compared with the compositions of the prior art makes it possible to assert that the bioavailability of ivermectin in the compositions according to the invention is greater than that of the compositions of the prior art.

The applicant has shown, unexpectedly, that a composition based on a macrocyclic lactone, such as ivermectin, and on closantel or a salt thereof such as the sodium salt, for example, in an oleaginous vehicle in which the macrocyclic lactone is in solution and the closantel or a salt thereof is in suspension, given orally to sheep exhibits values for maximum plasma concentration of macrocyclic lactone that delimit a concentration range of between 12.54 ng/ml and 21.61 ng/ml. This concentration range extends approximately to double the lowest value, whereas it is known from the data of the literature that, for oral compositions in an organic solvent, including water, it is between 6.4 ng/ml Gogolewski et al., Vet.

Parasitology, 1995, 60, 297-302) and 31.66 ng/ml McKellar et al., Vet. Parasitology, 39, 1/2, 123- 136,1991), i.e. a range of values varying from 1 to almost 5 times the minimum value.

00 9 0

C

Since the effectiveness of a treatment based on a Smacrocyclic lactone is directly dependent on the bioavailability of the active principle, which itself depends in general on the amount of active principle in the composition, it is therefore possible, with ND compositions according to the invention, to reduce the r- amount of macrocyclic lactones, which are ecotoxic 00 l compounds, while at the same time improving their M bioavailability in order to provide the desired S 10 effectiveness. Thus, in the case of ivermectin provided in i(1 an oleaginous oral composition in accordance with the invention, in order to guarantee the effectiveness, the amount usually recommended can be reduced by at least Thus, the novel oral compositions described, by virtue of the improved bioavailability that they provide, and by virtue of the decrease in the dose of macrocyclic lactone administered, make it possible to decrease the harmful effect on the environment. This represents both an economical and ecological advantage.

The present invention is directed to providing oleaginous oral compositions which provide: -a decrease in the amount of active principles and/or of their metabolites excreted into the environment while at the same time maintaining antiparasitic activity on all the parasite families sensitive to the active principles of the combination, a stability of at least 2 years for the oral compositions in order to preserve the optimum effectiveness thereof, i.e. conservation of at least and preferably of at least 95% of the initial amount of the active principles, and in particular of the closantel and/or salts thereof, for 2 years, N:\Melbourne\Caaea\Patent\54000-54999\P54986.AU\Specis\P54986.AU Specification 2008-6-1l.doc 10 -good acceptability for the animals treated.

A subject of the present invention is oleaginous oral compositions, characterized in that they comprise: an oleaginous vehicle, at least one compound chosen from macrocyclic lactones, in solution in the oleaginous vehicle, at least one compound chosen from closantel or a salt thereof, in suspension in said oleaginous vehicle.

Macrocyclic lactones such as the compounds LL-F28249, milbemycins and avermectins have been very widely used, for a number of years, in the veterinary field for the treatment of nematode infestations and against arthropods.

The family of very active compounds LL-F28249 consists of natural endectocides isolated from Streptomyces cyaneogriseus subsp. noncyanogenus fermentation baths.

US patent No. 5,106,994 and US patent No. 5,169,956 describe the preparation of the major and minor compounds LL-F28249.alpha.-.lambda.. The LL-F28249 compound family also comprises, but is not limited by, the 23-oxo and 23-imino semisynthetic derivatives of LL-F28249.alpha.-.lambda., as is taught in US patent No. 4,916,154. Moxidectin, chemically known as 23-(0methyloxime)-LL-F28249.alpha., is a particularly active 23-imino derivative. Other examples of LL-F28249 derivatives that are included in the present invention are 23-(semicarbazone)-LL-F28249.alpha. and 23- (thiosemicarbazone)-LL-F28249.alpha..

Milbemycins, also known as B-41 series antibiotics, are natural macrocyclic lactones isolated from Streptomyces hygroscopicus subsp. aureolacrimosus. US patent No. 3,950,360 teaches the preparation of the macrolide antibiotics milbemycin.sub..alpha.1-alpha.10, milbemycin.sub..beta.l-.beta.3, etc. These compounds 11 are commonly referred to as milbemycin A, milbemycin B, milbemycin D, etc., or antibiotic B-41A1, antibiotic B-41A3, etc.

Avermectins, also known as the C-076 compound family, are natural macrocylic lactones produced by Streptomyces avermitilis. US patent No. 4,310,519 describes the isolation and preparation of the major compounds Ala (avermectin Ala), A2a, Bla and B2a, and of the minor compounds Alb (avermectin Alb), A2b, Bib and B2b. The C-076 compound family also comprises the semisynthetic derivatives such as the 22,23dihydroavermectins described in US patent No. 4,199,569. The semisynthetic derivatives comprise, but are not limited to, ivermectin, abamectin, doramectin, eprinomectin and selamectin.

Ivermectin (IVM), chemically defined as 22,23dihydroavermectin B1 or 22,23-dihydro C-076 Bl, is known to be an effective and relatively nontoxic anthelmintic (Campbell, Ivermectin and Abamectin, Springer, 1989). IVM has in particular been used orally, by subcutaneous injection or by transdermal injection, for many years, for treating infestations in particular with nematodes in animals and in humans.

According to another advantageous embodiment of said oleaginous oral compositions, the macrocyclic lactones are advantageously chosen from ivermectin, abamectin, eprinomectin, doramectin, selamectin, milbemycin oxime, and moxidectin.

Closantel, or 5'-chloro-4'-(4-chloro-.alpha.and the salts thereof are known for their activity on trematodes (such as, for example, Fasciola hepatica), hematophagous nematodes (such as, for example, Haemonchus contortus, Chabertia ovina.), the larval 12 stages of Hypoderma spp. and other parasites that infest animals.

The oleaginous vehicle is chosen from mineral oils, such as for example paraffin oil, or from plant oils, such as for example sesame oil, soybean oil, groundnut oil, coconut oil or cottonseed oil, or from semisynthetic plant oils obtained by fractionation and/or hydrolysis and/or esterification of natural plant oils, such as for example diesters of propylene glycol and of fatty acids or triglycerides of fatty acids derived from coconut oil. The oleaginous vehicle may also consist of a mixture of these oils.

According to an advantageous embodiment of said oleaginous oral compositions according to the invention, the oleaginous vehicle is chosen from plant oils, such as for example sesame oil, soybean oil, groundnut oil or cottonseed oil, and also mixtures thereof. Preferably, the oleaginous vehicle comprises soybean oil.

According to another advantageous embodiment of said oleaginous oral compositions, they comprise closantel sodium.

Advantageously, the oral composition according to the invention will have to be prepared with closantel or a salt thereof, for which the particle size is between 0.01 and 100 pm, and preferably between 0.1 and 20 pm.

According to another advantageous embodiment of said oleaginous oral compositions, they may also comprise at least one of the following compounds: thickeners such as ethyl- or methylcellulose, hydroxyethyl- or hydroxypropylcelluse, hydroxypropylmethylcellulose, the sodium or potassium salt of carboxymethylcellulose, carbomers, colloidal silicas and silicates, microcrystalline celluloses, polyvinyl alcohols, 13 povidones, copolymers of acrylic acid or methacrylic acid, aluminum stearates, anticaking agents, antiaggregating agents, adsorbents such as bentonites, colloidal silicas, magnesium trisilicate, talc, calcium phosphates, solubilizing agents that facilitate dissolution or prevent precipitation of the macrocyclic lactones in the oleaginous vehicle, such as glyceryl monostearate, polyoxyethylenated castor oils, polyoxyethylenated esters of sorbitol, benzyl alcohol, triacetin, propylene glycol, glycerol, glycofurol, glycerol formal, antioxidants such as vitamin E and its derivatives, ascorbic acid and its derivatives, 2-tertbutyl-4-methoxyphenol, 2,6-di-tert-butyl-4-methylphenol, propyl gallate, chelating agents such as edetic acid and its salts, citric acid and its salts, antimicrobial, antibacterial or antifungal preserving agents such as benzyl alcohol, trichlorobutanol, phenol, and esters of p-hydroxybenzoic acid.

According to yet another embodiment of said oleaginous oral compositions, they contain: between 0.01 and 0.48% (by weight relative to the total composition) of at least one macrocyclic lactone, between 1 and 24% (by weight relative to the total composition) of closantel or of a salt thereof, an oleaginous vehicle chosen from plant oils, semisynthetic oils or mineral oils.

According to a particularly preferred embodiment of said oleaginous oral compositions, they contain: between 0.04 and 0.08% (by weight relative to the total composition) of avermectins BI or 22,23dihydroavermectins Bi (ivermectins), approximately 4% (by weight relative to the total composition) of closantel in the sodium form thereof, soybean oil.

14 Advantageously, in the oleaginous oral compositions with endoparasitic and ectoparasitic activity according to the invention, when they are administered to an animal, the weight ratio of the macrocyclic lactones to the closantel and/or salts thereof is in general between 1:200 and 1:10, and preferably between 1:100 and 1:50. According to yet another preferred arrangement of the invention, the oral composition is a medicinal product.

According to yet another preferred arrangement of the invention, the oral composition is used for preparing a medicinal product for the prevention and/or treatment of endoparasites and/or of ectoparasites.

The oral compositions according to the invention may be administered to the animals orally (in the form of a drench for example) either directly or extemporaneously prediluted with, inter alia, water.

The oral compositions according to the invention may advantageously comprise other medicinal active principles with a view to broadening the spectrum of activity of the composition, to improving the antiparasitic effectiveness and/or to preventing and/or treating other pathologies of the animal.

The compositions are prepared and packaged, in a manner known to those skilled in the art, so as to preserve the integrity of the molecules.

The invention will be understood more fully on reading the additional description which follows and which refers to examples of preparation of oleaginous oral compositions in accordance with the invention, and of demonstration of their particular properties. It should be clearly understood, however, that these examples are 15 only given as illustrations of the invention and in no way constitute a limitation thereof.

EXAMPLE 1 Bioavailability of ivermectin and of closantel in sheep when administered orally, and composition acceptability by the animals.

A-1st trial a) Procedure: Each of the 4 groups of 6 sheep, each sheep weighing between 25 and 40 kg, the groups being composed homogeneously of sheep of European race and of both sexes, was treated orally with one of the following oral compositions: An oleaginous oral composition A and an organic composition B are prepared according to the techniques known to those skilled in the art, and commercial oral preparations of formula C and D are used.

The content of compositions A to D is illustrated in table I below. The amounts of the components are expressed as percentage by weight, gram, relative to the total volume, 100 ml, of the composition. The final volume is obtained by addition of soybean oil to composition A, by addition of water to composition B, and by addition of the excipient for the commercial compositions D and C.

The oleaginous suspension of formula A is an oleaginous composition according to the invention.

The organic solution B is an organic composition containing the macrocyclic lactone, and the closantel in the form of the sodium salt, representing the compositions described in the literature or equivalent 16 to those that are commercially available. In order to have better stability, this solution is first of all prepared with an exclusively organic vehicle in which the concentrations of ivermectin and of closantel in the form of the sodium salt are multiplied by four. In order to avoid severe irritations when administered to the animals, it is diluted four-fold with water at the time of its use.

Composition C corresponds to a commercial product "Oramec®" marketed by the laboratories MERIAL Animal Health Limited.

Composition D corresponds to the product "Flukiver®" marketed by Janssen Animal Health BVBA.

Table I FORMULA

_COMPOSITION

A C D (diluted) Ivermectin 0.08 0.08 0.08** (22,23-dihydroavermectins Bla/Bib) Closantel* 4.0 4.0 Anticaking agent 1.58 (colloidal silica) Antioxidant agent 0.03 0.0075

(BHA/BHT)

Preserving agent 1.00 (benzyl alcohol) Polyvinylpyrrolidone Propylene glycol 25 ml Water q.s. 100 ml 20.72 Soybean oil q.s. 100 ml Excipient q.s. 100 ml 100 ml The closantel is introduced in the form of the sodium salt in an amount sufficient to guarantee a closantel content of 4% in the final composition.

17 The ivermectin present in the commercial formulation was assayed and an overdose of 10% was demonstrated relative to the amounts stated on the label of the marketed product. Thus, there is 0.088% of ivermectin in the final composition.

b) Method of treatment of the groups: b-1) Treatment: Each animal of each group was given, orally in a single administration, using a drug-dosing pistol, the following volumes: group A: 1 ml per 4 kg of live weight 200 pg/kg of ivermectin and 10 mg/kg closantel), group B: 1 ml per 4 kg of live weight 200 ig/kg of ivermectin and 10 mg/kg closantel), group C: 1 ml per 4 kg of live weight 200 jpg/kg of ivermectin), and group D: 1 ml per 5 kg of live weight 10 mg/kg of closantel).

b-2) Blood samples and analysis: 9 ml of blood were taken from each animal, on heparin tubes, before treatment and after treatment with one of compositions A, B, C and D at 2, 4, 8, 12, 24, 48 and 72 hours and then after 7, 14, 21, 28 and 35 days.

The sample analysis was carried out according to conventional techniques known to those skilled in the art.

c) Comparative study of the bioavailability of the active molecules: c-1) Ivermectin: The plasma concentrations (standard deviation), expressed in ng of ivermectin per ml as a function of time, are given in table II below: 1, 18 Table II Time in days Concentrations Time in days Composition A Composition B Composition C 0.00 LDD LDD LDD 0.08 0.20 0.28 2.21 3.16 4.88 8.72 0.16 3.19 1.82 9.11 5.48 9.34 10.59 0.33 14.68 4.95 16.15 4.70 13.24 5.02 0.50 20.19 1.42 15.87 4.70 14.26 4.13 1.00 16.62 3.18 10.65 4.13 10.24 4.30 2.00 7.86 2.45 4.34 1.44 4.08 2.26 3.00 4.44 1.70 1.67 0.87 1.81 1.10 7.00 0.78 0.58 0.30 0.14 0.28 0.15 14.00 0.18 0.24 0.21 0.21 LDD 21.00 LDD 0.12 0.17 LDD 28.00 0.03 0.01 LDD LDD 35.00 LDD LDD LDD LDD: Value less than the limit of detection, it is replaced with the value 0.025 ng/ml, which corresponds to LDD/2, for the calculations and the representations as graphs.

c-2) Closantel: The plasma concentrations (standard deviation), expressed in ptg of closantel per ml as a function of time, are given in table III below: 19 Table III Time in days Concentrations Time in days Composition A Composition B Composition D 0.00 LDD LDD LDD 0.08 LDD 4.51 6.79 0.57 1.27 0.16 4.98 3.32 18.62 12.29 8.58 4.16 0.33 32.86 15.11 43.90 13.04 43.06 14.98 0.50 44.21 9.42 55.72 9.51 51.44 5.60 1.00 63.24 11.54 65.11 8.1 69.13 7.68 2.00 59.56 10.10 60.46 5.53 64.22 5.33 3.00 57.99 9.47 59.33 6.81 60.37 4.92 7.00 47.43 7.68 48.63 5.80 50.41 3.85 14.00 42.95 9.68 43.13 5.90 43.93 4.75 21.00 38.11 8.82 37.73 5.70 38.59 4.82 28.00 30.63 7.44 30.13 5.20 30.92 3.44 35.00 24.52 6.05 26.08 5.06 26.44 3.34 LDD: Value less than the limit of detection, it is replaced with the value 0.05 g/ml, which corresponds to LDD/2, for the calculations and the representations as graphs.

B 2 nd trial a) Procedure: Each of the 5 groups of 6 sheep, each sheep weighing between 24 and 34 kg, the groups being composed homogeneously of sheep of European race and of both sexes, was treated orally with one of the following oral compositions: An oleaginous oral composition A, an oleaginous oral composition E and an oleaginous oral composition F are prepared according to techniques well known to those skilled in the art, and commercially available oral preparations of formula C and D are used.

20 The content of compositions A, C, D, E and F is illustrated in table IV below. The amounts of the components are expressed as percentage by weight, gram, relative to the total volume, 100 ml, of the composition. The final volume is obtained with soybean oil in compositions A, E and F, and the excipient for the commercial compositions C and D.

The oleaginous suspension of formula A corresponds to an oleaginous composition according to the invention, which composition is identical to composition A used in the first trial.

Suspension E corresponds, similarly, to the oleaginous composition of formula A, but containing only closantel, in the form of the sodium salt.

Suspension F corresponds, similarly, to the oleaginous composition of formula A, but containing only ivermectin.

Composition C corresponds to a commercial product "Oramec®" from the laboratories of MERIAL Animal Health Limited, which commercial composition is identical to composition C used in the first trial.

Composition D corresponds to a commercial product "Flukiver® from Janssen Animal Health BVBA, which commercial composition is identical to composition D used in the first trial.

21 Table IV FORMULA

COMPOSITION

A E F C D Ivermectin 0.08 0.08 0.08** (22,23-dihydroavermectins Bla/Bib) Closantel* 4.0* 4.0* Anticaking agent 1.58 1.58 1.58 (colloidal silica) Antioxidant 0.03 0.03 0.03

(BHA/BHT)

Preserving agent 1.00 1.00 1.00 (benzyl alcohol) Soybean oil q.s. 100 ml 100 ml 100 ml Excipient q.s. 100 ml 100 ml The closantel is introduced in the form of the sodium salt in an amount sufficient to guarantee a closantel content of 4% in the final composition.

The ivermectin present in the commercial formulation was assayed and an overdose of 10% was demonstrated relative to the amounts stated on the label of the marketed product. Thus, there is 0.088% of ivermectin in the final composition.

b) Method of treatment of the groups: b-l) Treatment: Each animal of each group is given, orally in a single administration, using a drug-dosing pistol, the following volumes: group A: 1 ml per 4 kg of live weight 200 rig/kg of ivermectin and 10 mg/kg closantel), group E: 1 ml per 4 kg of live weight 10 mg/kg closantel), group F: 1 ml per 4 kg of live weight 200 rg/kg of ivermectin), group C: 1 ml per 4 kg of live weight 200 jg/kg of ivermectin), and 22 -group D: 1 ml per 5 kg of live weight 10 mg/kg of closantel).

b-2) Blood samples and analysis: The procedure is described in the first trial.

c) Comparative study of the bioavailability of the active molecules: c-1) Ivermectin: The plasma concentrations (standard deviation), expressed in ng of ivermectin per ml as a function of time, are given in Table V below: Table V Time in days Concentrations Time in Composition A Composition F Composition C 0.00 0 0 0 0.08 7.21 4.58 2.04 1.06 19.72 20.05 0.16 11.91 5.94 6.87 2.68 23.03 14.40 0.33 16.36 5.36 14.69 2.17 22.49 8.48 0.50 16.81 4.27 14.99 4.60 20.6 7.38 1.00 14.29 4.97 12.36 6.32 14.5 5.16 2.00 6.91 2.76 5.34 3.00 7.13 2.31 3.00 3.92 1.30 3.17 1.96 3.78 1.92 7.00 0.9 0.26 0.73 0.44 0.87 0.42 14.00 0.21 0.17 0.16 0.10 0.14 0.10 21.00 0.03 0.07 0.04 0.06 0.03 0.04 28.00 LDD LDD LDD 35.00 LDD LDD LDD LDD: Value less than the limit of detection, it is replaced with the value 0.025 ng/ml, which corresponds to LDD/2, for the calculations and the representations as graphs.

23 c-2) Closantel: The plasma concentrations (standard deviation), expressed in pg of closantel per ml as a function of time, are given in table VI below: Table VI Time in days Concentrations Time in Composition A Composition E Composition D 0.00 LDD LDD LDD 0.08 9.34 4.74 5.43 8.51 6.36 6.27 0.16 25.22 8.65 13.63 11.70 18.23 7.59 0.33 44.18 10.52 28.06 8.48 40.54 11.77 0.50 51.62 8.28 38.77 7.47 47.34 13.15 1.00 59.25 9.10 49.7 5.82 59.63 8.85 2.00 56.17 6.22 50.61 7.66 57.33 8.41 3.00 50.28 5.76 45.52 6.06 54.2 7.65 7.00 41.44 6.52 38.66 7.05 45.11 7.15 14.00 30.98 7.71 30.8 6.56 35.31 7.02 21.00 24.62 6.83 25.17 6.78 30.23 5.17 28.00 19.06 6.17 18.93 4.74 22.87 4.63 35.00 14.88 5.82 15.13 4.43 16.74 5.31 LDD: Value less than the limit of detection, it is replaced with the value 0.05 pg/ml, which corresponds to LDD/2, for the calculations and the representations as graphs.

C Results: Bioavailability is defined, inter alia, by the amount of active material(s) that arrives in the circulation, i.e. by the Cmax (maximum plasma concentration) represented by the top of the peak on the curve, and by the AUC (area under the curve for the plasma). For each parasite, the minimum amount of the active material required to reach a lethal activity on the target parasites is known. Thus, the reference products, Oramec® for ivermectin and Flukiver® for closantel, give 24 us the minimum thresholds to be reached for the least sensitive (dose-limiting) parasite.

As shown in Figures 1 and 3, given in the appendix, the maximum amount of circulating ivermectin obtained (plasma peak) with composition A according to the invention is 21.61 ng/ml (trial 1) and 12.54 ng/ml (trial and it is between 10.13 ng/ml (trial 1) and 27.98 ng/ml (trial 2 at t 0.50 d) for the commercial reference product, composition C (the measurements obtained in trial 2 at t 0.16 d and at t 0.30 d confirm the extreme variability of the plasma concentrations observed for ivermectin in composition

C).

These results confirm what is known in the literature for composition C, namely a very great variability of the Cmax. On the other hand, the results obtained with composition A according to the invention are within a narrower Cmax range, even taking into account the variability due to an in vivo test. An increase of more than 19% is noted when comparing the maximum circulating amount of ivermectin obtained in the second trial with composition A according to the invention to the maximum circulating amount of ivermectin obtained in the first trial with the commercial composition C.

These results demonstrate the better reliability of the administration of ivermectin when it is introduced in compositions according to the invention compared with the commercial compositions which comprise only ivermectin. Thus, to obtain the maximum circulating amount of ivermectin, it is sufficient to use, for composition A in accordance with the invention, only 0.065% w/w of ivermectin. Moreover, if the overdose of 10% of ivermectin in formula C is also taken into account, the required amount of macrocyclic lactone is reduced by 25% while at the same time keeping the desired antiparasitic activity.

25 The weight ratio of ivermectin to closantel is 1:50 in composition A and can be taken to 1:62.5 while keeping the desired antiparasitic activity of the macrocyclic lactone.

It is noted that, compared to compositions comprising ivermectin and closantel in solution in organic medium (composition the compositions according to the invention have a Cmax and AUC value that is increased for ivermectin and conserved for closantel.

As shown in Figures 2 and 4, the compositions, whatever their formulation, give maximum amounts of closantel that are respectively very similar, between 49.70 and 69.16 pg/ml, which shows, moreover, good reproducibility given the variability due to in vivo tests carried out at different times. It is deduced from this that the composition according to the invention has not modified the bioavailability and, consequently, the effectiveness of closantel.

Acceptability by the animals treated: In the course of the trials, the applicant moreover evaluated the taking of the oleaginous oral composition according to the invention in order to verify that it was well accepted by the treated animal compared with already marketed oral compositions.

The animals' behavior was observed by the operator who administers the treatment. No difference was detected as regards the accepting of the drinkable compositions by the animals in the various groups.

Thus, the oleaginous oral composition according to the invention is well accepted and tolerated by the treated animals, which confirms the ease of use for the individual administering the composition according to 26 the invention and the safety of use, since the animal does not refuse the treatment.

EXAMPLE 2 Comparative study of the stability of ivermectin and of closantel.

An oleaginous oral composition A according to the invention in the form of a suspension, an oleaginous oral composition G in the form of a solution and an oral composition in organic medium B are prepared according to techniques known to those skilled in the art.

The content of compositions A, B and G is illustrated in table VII. The amounts of the components are expressed as percentage by weight (gram) relative to the total volume (100 ml) of the composition. The results of the stability tests are summarized in table VIII.

27 Table VII: Qualitative and quantitative compositions of the compared formulations

COMPOSITIONS

FORMULA

A B G Ivermectin 0.08 0.32 0.08 (22,23-dihydroavermectins Bia/Bib) Closantel* 4.0 16.0 Anticaking agent 1.58 (colloidal silica) Antioxidant 0.03 0.03 0.03

(BHA/BHT)

Polyvinylpyrrolidone Preserving agent 1.00 1.00 (benzyl alcohol) Soybean oil q.s. 100 ml Propylene glycol q.s. 100 ml Polyoxyethylenated glycerides 100 ml comprising glycose q.s.

The closantel is introduced in the form of the sodium salt in an amount sufficient to guarantee a closantel content of 4% in the final composition.

Table VIII: Comparative measurements of the stability of the formulations over time 0 T 0 months T 4 months 0 C 40 0 C 25 0 C 40 0

C

Clos Iver Clos Iver Clos Iver Clos Iver Comp. A 96.15 100.2 96.15 100.2 96.27 100.2 99.6 101.9 Comp. B 95.75 97.32 95.75 97.32 96.17 97.16 90.94 81.53 Comp. G 95.02 102.7 95.02 102.7 90.19 100.3 84.36 98.41 28 T 6 months 0 C 40 0

C

Clos Iver Clos Iver Comp. A 95.0 99.67 97.4 99.8 Comp. B 94.40 96.74 ND ND Comp. G 86.54 97.96 ND ND The amount of active principles (ivermectin and closantel) in the compositions is assayed and the percentage of active material remaining relative to the amount introduced is calculated. The result is given in table VIII. It is noted that, after 6 months at 250C, composition A still contains more than 98.8% of closantel relative to the amount initially introduced, and that composition G, on the other hand, now only contains 91% thereof. At 400C, the stability of closantel in composition A is 100%. A significant difference in the stability of closantel in compositions A and G is therefore noted. The stabilities of ivermectin and of closantel used in an oleaginous composition A, in which the ivermectin is in solution and the closantel is in suspension in accordance with the invention, are completely stable compared with composition G in which the ivermectin is in solution and the closantel is in solution, and compared with solution B which comprises an organic solvent.

It is recognized that a demonstration of 6 months of stability at a temperature of 40°Celsius is equivalent to a stability of 24 months (2 years) under ambient conditions.

EXAMPLE 3 Oleaginous composition in accordance with the invention for oral administration: doramectin 0.06% (w/v) closantel (sodium salt) 4.0% (w/v) 00 29 c- anticaking agent (colloidal silica) 1.0% (w/v) antioxidant (BHT) 0.1% (w/v) ethyl oleate 22.0% (w/v) sesame oil q.s. for 100.0 ml I EXAMPLE 4 00 l Oleaginous composition in accordance with the invention Sfor oral administration: eprinomectin 0.06% (w/v) C closantel (sodium salt) 4.0% (w/v) anticaking agent (colloidal silica) 1.0% (w/v) antioxidant (BHT) 0.1% (w/v) capric/caprylic triglycerides q.s. for 100.0 ml In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

N:\Melbourne\Cases\Patent\54000-54999\P54986.AU\Specie\P54986.AU Specification 2008-6-11.doc

Claims (21)

1. An oleaginous composition, characterized in that it comprises: an oleaginous vehicle, S- at least one compound chosen from macrocyclic lactones, in solution in the oleaginous vehicle, 00 t~ at least one compound chosen from closantel or a salt thereof, in suspension in said oleaginous vehicle. 8 0C

2. The composition as claimed in claim 1, characterized in that it exhibits a stability of the active principles of at least 90% for 2 years.

3. The composition as claimed in claim 2, characterized in that it exhibits a stability of the active principles of at least 95% for 2 years.

4. The composition as claimed in any one of claims 1 to 3, characterized in that the vehicle is chosen so as to be suitable for oral administration.

The antiparasitic composition as claimed in any one of claims 1 to 3, characterized in that the weight ratio of the macrocyclic lactones to the closantel and/or salts thereof is between 1:200 and 1:10.

6. The composition as claimed in claim 5, characterized in that the weight ratio of the macrocyclic lactones to the closantel and/or salts thereof is between 1:100 and 1:50.

7. The composition as claimed in any one of claims 1 to 6, characterized in that the macrocyclic lactone is chosen from the group consisting of the compounds LL-F28249, of milbemycins and of avermectins.

N:\Melbourne\Cases\Patent\54000-54999\P54986.AU\Specis\PS4986AU Specification 2008-6-11.doc 00 31 S8. The composition as claimed in claim 7, characterized in that the macrocyclic lactone is chosen from the group consisting of ivermectin, abamectin, eprinomectin, doramectin, selamectin, milbemycin oxime, and moxidectin. \O r-

9. The composition as claimed in any one of claims 1 to 00 ln 8, characterized in that the closantel is present in the form of the sodium salt. C

10. The composition as claimed in any one of claims 1 to 9, characterized in that the particle size of closantel or of salts thereof is between 0.01 and 100 pm.

11. The composition as claimed in claim 10, characterized in that the particle size of closantel or of salts thereof is between 0.1 and 20 jm.

12. The composition as claimed in any one of claims 1 to 11, characterized in that the oleaginous vehicle is chosen from mineral oils, plant oils, semisynthetic plant oils and mixtures thereof.

13. The composition as claimed in any one of claims 1 to 12, characterized in that the oleaginous vehicle is chosen from plant oils.

14. The composition as claimed in claim 13, characterized in that the oleaginous vehicle is soybean oil. The composition as claimed in any one of claims 1 to 14, characterized in that it also comprises at least one of the following compounds: thickeners, anticaking agents, anti-aggregating agents, adsorbing agents, solubilizing agents, antioxidants, chelating agents, antimicrobial, antibacterial and antifungal preserving agents.

N:\Melkburne\Cases\Patent\540OO-54999\P54986.AU\Specis\P54986.AU Specification 2008-6-1l.doc 00 32

16. The composition as claimed in any one of claims 1 to characterized in that it comprises: between 0.01 and 0.48% by weight, relative to the total weight of the composition, of at least one ND macrocyclic lactone, between 1 and 24% by weight, relative to the total 00 I weight of the composition, of closantel or of a salt thereof, S 10 an oleaginous vehicle chosen from plant oils, C semisynthetic oils or mineral oils.

17. The composition as claimed in any one of claims 1 to 16, characterized in that it comprises: between 0.04 and 0.08% by weight, relative to the total weight of the composition, of avermectins Bi or 22,23-dihydroavermectins Bi (ivermectins), approximately 4% by weight, relative to the total weight of the composition, of closantel sodium, soybean oil.

18. The composition as claimed in any one of claims 1 to 17, for its use as a medicinal product, or antiparasitic composition.

19. Use of a composition as claimed in any one of claims 1 to 18, for preparing a medicinal product for the prevention and/or treatment of endoparasites and/or of ectoparasites, or a parasite chosen from plathelminthes, nemathelminthes and arthropods.

A method of preventing and/or treating endoparasites, or a parasite chosen from plathelminthes, nemathelminthes and arthropods which comprises administering a therapeutically effective amount of a composition as claimed in any one of claims 1 to 18. N:\Melbourne\CaseB\Patent\54000-54999\P54986.AU\Specis\P54986.AU Specification 2008-6-1l.doc 00 33

21. An oleaginous composition, uses of the composition or __methods involving the use of the composition, substantially as herein described with reference to any one of the Examples and/or Figures. 00 N:\Melbourne\cases\Patent\54000-54999\P54986.AU\Specig P54986.AU Specification 2008-6-1ldoc