WO2012001083A2

WO2012001083A2 - Novel eprinomectin injectable compositions

Info

Publication number: WO2012001083A2
Application number: PCT/EP2011/060969
Authority: WO
Inventors: Hannelie Cilliers
Original assignee: Ceva Sante Animale Sa
Priority date: 2010-06-29
Filing date: 2011-06-29
Publication date: 2012-01-05
Also published as: WO2012001083A3; RU2013103140A; RU2578036C2

Abstract

An improved injectable parasiticide composition for treating infections caused by ectoparasites and endoparasites, wherein the formulation comprises a solvent system comprising polyethylene glycol and optionally other excipients and a pharmaceutically acceptable solvent or mixture of solvents and co-solvents, said novel formulation being capable of improving the bioavailability and residence time of the parasiticide in the treated non human mammals. Preferred compositions according to the invention comprise parasiticides which are macrocyclic lactones having poor liphophilic properties, such as for example eprinomectin.

Description

NOVEL EPRINOMECTIN INJECTABLE COMPOSITIONS

FIELD OF THE INVENTION

[001] This invention relates to novel compositions useful in the field of veterinary medicine and more particularly in relation to anti-parasitic formulations comprising macrocyclic lactones like eprinomectin, having improved bioavailability and long lasting therapeutic effects.

BACKGROUND OF THE INVENTION

[002] Warm-blooded animals are subject to attack by parasites, and man has long sought to combat such parasites afflicting domestic companion animals, farmed livestock and exotic animals, to alleviate suffering and for commercial gain. Internal and external parasites, such as gastrointestinal worms and lice, are organisms that feed on a host animal's tissue, blood, and tissue fluids and can interfere with production. Internal parasites can cause appetite suppression, reduced feed digestibility and nutrient absorption, blood loss, and anemia, which in turn can lead to decreased weight gain and milk production, weakened immune system, and tissue and organ damage. External parasites can cause hair loss and scabbing, blood loss and anemia, and skin irritation, as well as acting as a disease vector. The effects of external parasites on production can include decreased weight gain and milk production, hide damage, and damage to facilities and fences from rubbing and scratching.

[003] The macrocyclic lactones, such as for example, avermectins and milbemycins, are very potent antiparasitic agents at low dose and are useful against a broad spectrum of endoparasites and ectoparasites in mammals as well as having agricultural uses against various parasites found in and on crops and soils. They are active against many immature nematodes (including hypobiotic larvae) and arthropods. Moreover, a single therapeutic dose can persist in concentrations sufficient to be effective against incumbent nematode infections for prolonged periods after treatment.

[004] The avermectins in commercial use are ivermectin, abamectin, doramectin, eprinomectin, and selamectin. Commercially available milbemycins are milbemycin oxime and moxidectin. The basic avermectin compounds are isolated from the fermentation broth of the soil micro-organism Streptomyces avermitilis and these compounds are described in US patent No. 4,310,519. Furthermore, derivatives of these basic avermectin compounds have been prepared by a variety of chemical means.

[005] Specifically, eprinomectin, which is also named 4'-epi-acetylamino-4'-deoxy- avermectin Bl, is a novel semi-synthetic derivative of the avermectin family characterized by the following structure :

[006] Eprinomectin is a mixture of two homologues, eprinomectin Bla (90%) and eprinomectin Bib (10%), the difference between them being the existence of a methylene group in C-25. These structures possess a wide activity spectrum against nematodes and anthropods and their effectiveness against both endo-and ectoparasites has led them to be called endectocides.

[007] The pharmaceutical activity of these molecules increases the permeability of parasites muscle and nervous cells to chlorine ions, thus causing the parasite's paralysis and death. They bind to the glutamate-controlled chlorine channels of invertebrates' cells. They may also bind to other GABA-controlled chlorine channels. Since mammals do not possess this type of glutamate-controlled chlorine channel, these molecules provide a high degree of safety, even if used at high doses.

[008] Macrocyclic lactones are generally liphophilic compounds with rather high partition coefficients or logP values, say for example about 6 for moxidectin, about 5.6 for doramectin, and about 4.8 for ivermectin, except for eprinomectin which has the lowest logP value of about 4.4 (See Example 2; and Kaliszan R. and al., Pure Appl. Chem., Vol. 73, No. 9, pp. 1465-1475, IUPAC 2001). They are thus generally well absorbed when administered orally, parenterally, or as pour-on formulations. They are extensively distributed throughout the body, including gastro intestinal system, lungs and skin, and concentrate particularly in adipose tissue, with a high residence time and half life (Ti_/2) in the animal's tissues.

[009] Residence time and half life of these macrocyclic lactones may however be affected by the body condition of the animal, the route of administration as well as the formulation and/or solvents. For example, it is known that oily formulations have longer residence time than aqueous formulations. Also, parenteral and topical formulations generally have better residence time than oral formulations. For example, residence timeof macrocyclic lactones when administered as pour-on formulations can be about 12.8 days for moxidectin and doramectin, about 8.4 days for ivermectin, and about 4.16 days for eprinomectin.

[0010] Eprinomectin-based products currently available in the market include formulations for external use such as pour-on formulations containing 0.5% w/v eprinomectin solution which can be applied over the skin of the animal. Eprinomectin received a marketing authorization for topical pour-on administration, and is currently marketed by Merial under the trademark Eprinex for treating and/or preventing roundworms, lungworms, grubs, lice, mites, and horn flies in cattle. The Eprinex pour- on formulation currently comprises 5 mg eprinomectin, 0.10 mg butylhydroxytoluene, 0.06 mg Vitamin E and excipients. [0011] Although pour-on methods have some advantages with regards to the applicator's safety, it is also largely affected by several factors which may reduce its efficacy due to the imprecision of its dosage. The uptake efficiency or adsorption of the drug is generally affected by the conditions of animal's skin like fur, presence of cuts, wounds, burns, as well as by the cleanness of the skin of animals (presence of dust, mud, etc...)- Also, environmental factors, including climatic conditions like rains, solar radiations etc... may affect the adsorption efficacy.

[0012] All these adverse conditions make it compulsory to more than double the necessary quantity of drug in order to combat the parasite. The requirement for this supplementary addition of eprinomectin has economic consequences regarding the cost per treated animal, may have a negative impact on the environment, and further can lead to potential side effects resulting from high drug dosage. [0013] Eprinomectin has been suggested for use as subcutaneous or intramuscular injectable formulations. In fact, in addition to its endectocide activity, eprinomectin was shown not to be eliminated through milk fat in production animals. Studies concluded that only 0.1% of the applied drug was eliminated through the milk, that is to say, 50 times less when compared to other known macrocyclic lactones, such as for example, ivermectin or moxidectin.

[0014] While eprinomectin would be, in theory, the preferred macrocyclic lactone particularly for treating dairy cattle, it however presents poor lipophilic property, low residence time and a shorter lasting effect or a shorter duration of action when compared to other macrocyclic lactones.

[0015] There is thus clearly a need for improving bioavailability and increasing the residence time or half life of eprinomectin drug in the body of the animal, and for providing methods of administering drugs with low toxicity and high tolerability. Also, in selecting formulation vehicles, the skilled person has to consider a number of issues including, solubility of eprinomectin, the affinity of the drug to certain vehicles, whether it will affect any essential auxiliaries, pH, stability over time, viscosity, and naturally the risk of any toxic effect upon the animal to be treated, but still maintaining very low residues in milk. Therefore, formulation of this parasiticide is a complex task and not a routine experimentation. [0016] To this regard, the US patent No. 5,773,422 describes formulations for parenteral or topical administration of an avermectin based upon the use of the N-methylpyrrolidone or 2-pyrrolidone or mixtures thereof to dissolve an avermectin, such as ivermectin. Also, European application EP 873 127 describes injectable macrocyclic lactone anthelminthic formulations for injection, containing a macrocyclic lactone, vegetable oil and aromatic alcohol as solvent having four or more carbon atoms. Preferred aromatic alcohol solvent includes benzyl alcohol, ethyl benzyl alcohol, phenethyl alcohol and other aromatic monohydric alcohols. Also, preferred vegetable oils are soybean oil, sesame oil and corn oil. It is disclosed that the use of these particular formulations allows the remanency of the anthelmintic on external and internal parasites. However, none of these prior known formulations solved the problem of increasing the residence time and bioavailability of the drug in the treated non human mammals.

[0017] Although polyethylene Glycol (PEG) was never described for increasing drug bioavailability and residence time, it has been surprisingly found in the present invention that the inclusion of an effective amount of PEG had a dramatic effect on the bioavailability of eprinomectin in parasiticidal formulations. Lower proportions of eprinomectin within the injectable formulations were thus required. Also, the novel eprinomectin compositions according to the present invention unexpectedly presented a longer lasting effect and a greater efficacy particularly against gastro-intestinal strongyles and ectoparasites in ruminant and dairy cattle. Furthermore, the eprinomectin compositions yielded stable eprinomectin plasma concentrations after administration, leading to an overall greater efficacy within the whole cattle herd coupled with lesser risks of inducing resistance to the active drug. SUMMARY OF THE INVENTION

[0018] Accordingly, it is an object of the present invention to provide an improved long- lasting veterinary injectable composition comprising a therapeutically effective amount of eprinomectin in a solvent system comprising a polyethylene glycol (PEG), and optionally other solvents and excipients.

[0019] In particular it is an object of the invention to provide a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin and PEG as solvent, for controlling a broad range of endoparasites and ectoparasites in non human mammals.

[0020] A still further object of the invention is to provide a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin and PEG as solvent, for treating and/or preventing infections caused by endoparasites and/or ectoparasites in non human mammals, particularly dairy cattle. Compositions according to the present invention are particularly effective for controlling digestive and pulmonary strongyles. [0021 ] An even further object of the invention is to provide a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin and PEG wherein eprinomectin active compound has an enhanced bioavailability and a greater half-life (Ti/₂) compared to known macrocyclic lactones such as ivermectin, doramectin, and moxidectin and compared to pour-on eprinomectin formulations.

[0022] An essential object of the invention is to provide a veterinary composition comprising a therapeutically effective amount of eprinomectin and PEG as solvent, for parenteral administration to bovines, more specifically lactating cows, in such a manner that less residues of macrocyclic lactone, particularly of eprinomectin, are found in the milk or the meat and offal of cows as compared to eprinomectin pour-on application. [0023] An alternate embodiment of the present invention provides an injectable parasiticidal composition prepared for treating animals, comprising a poorly lipophilic macrocyclic lactone, le_., having a partition coefficient or log P lesser than about 5, preferably from about 4 to about 5, and most preferably about 4.4 or about 4.5 in a physiologically acceptable solvent system suitable for injection, wherein the composition comprises polyethylene glycol that is effective to improve bioavailability and provides a long lasting effect or longer duration of action of the less lipophilic macrocyclic lactone.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1: is a graph showing with a linear scale the mean and SD plasma concentration profiles of eprinomectin (ng/mL) obtained after single subcutaneous administration of 200 μg/kg of EPRINOJECT and single Pour-on application of 500 μg/kg EPRINEX to cows. Figure 2: is a graph showing with a Log scale the mean and SD plasma concentration profiles of eprinomectin (ng/mL) obtained after single subcutaneous administration of 200 μg/kg of EPRINOJECT and Single Pour-on application of 500 μg/kg EPRINEX to cows. DETAILED DESCRIPTION

[0024] The present invention relates to an improved long-lasting injectable veterinary composition comprising a therapeutically effective amount of eprinomectin in a solvent system comprising polyethylene glycol (PEG) and optionally other solvents and excipients.

[0025] It has now been surprisingly found that while eprinomectin is poorly lipophilic compared to other macrocyclic compounds (Le_., moxidectin, doramectin, or ivermectin), injectable eprinomectin-based formulations may be prepared with an effective amount of PEG solvent, and these formulations have, previously unreported, improved properties in terms of residence time and consequently a higher lasting effect/duration of action when compared to other macrocyclic compounds. Further, the eprinomectin compositions according to the present invention have shown superior bioavailability, improved solubilizing properties of eprinomectin prior to administration, as well as a faster delivery of eprinomectin to the target sites.

[0026] The novel formulations of the present invention comprises from about 0.1 to about 10%, preferably from about 1 to about 5 %, most preferably about 1% of eprinomectin. The eprinomectin would typically be completely dissolved in the formulation. A formulation of the invention may comprise at least 20% PEG by weight. The formulation of the present invention may also comprise between 20 and 98% PEG by weight, preferably about 40% and 95% or most preferably about 93% PEG by weight.

[0027] A range of PEG solvents according to molecular weight is commercially available, and any of those, or others that may yet be made available, may be chosen for convenience provided that the PEG is presented or rendered available as a liquid during formulation. Typically, PEG 200 to 1500 can be used for the purposes herein, preferably low molecular weight PEG 200 to PEG 600 can be usefully employed in this invention. A preferred solvent system consists of PEG 200. PEG for use in the present invention is commercially available from numerous sources such as Sigma Chemical Co. or Fisher Scientific Co.

[0028] In a most preferred embodiment, the injectable veterinary eprinomectin composition according to the present invention comprises eprinomectin, PEG, N-methyl pyrrolidone and benzyl alcohol.

[0029] Further a pH regulator may be used to adjust the pH in the range of about 5.5 to about 9.5. Examples of pH regulators for use according to the present invention include citric acid, acetate, phosphoric acid, ascorbic acid, gluconic acid, succinic acid, tartaric acid, lactic acid, and the like, their salts thereof, and mixtures thereof.

[0030] The invention further relates to a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin and PEG as solvent, optionally with other solvents and excipients, for treating and/or preventing infections caused by endoparasites and/or ectoparasites in non human mammals.

[0031] In a preferred embodiment, the present invention relates to a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin and a solvent system comprising PEG, N-methyl pyrrolidone and benzyl alcohol, for treating and/or preventing infections caused by endoparasites and/or ectoparasites in non human mammals. [0032] The injectable veterinary composition according to the present invention may comprise a therapeutically effective amount of eprinomectin from about 0.5 to about 5%, benzyl alcohol in an amount of about 0.5 to about 5%, N-methyl pyrrolidone in an amount of about 0.5 to about 5 % and is formulated in polyethylene glycol,. Preferably, the injectable veterinary composition comprises eprinomectin in an amount of about 0.1 to about 1%, benzyl alcohol in an amount of about 0.1 to about 1%, N methyl pyrrolidone in an amount of about 0.5 to about 5 , and is formulated in polyethylene glycol

[0033] The injectable veterinary eprinomectin may comprise in addition to PEG, N- methyl pyrrolidone and benzyl alcohol, and optionally one or more pharmaceutically acceptable components that are suitable for use with non human mammals without undue adverse side effects (such as toxicity, irritation, and allergic response) commensurate with a reasonable benefit/risk ratio.

[0034] For example, the composition may include a liquid excipient or a pharmaceutically acceptable solvent or combination of solvents or co-solvents selected from the group consisting of pyrrolidone, propylene glycol, glycerol formal, isosorbid dimethyl ether, ethanol, dimethyl sulfoxide, glycerol, triethylene glycol tetrahydrofufuryl alcohol, triacetin, and the like. [0035] The reference parameter of lipophilicity, namely, the partition coefficient or log P, provides the thermodynamic measure of the hydrophilicity-lipophilicity balance of a chemical compound in a system comprising two immiscible liquids comprising an aqueous phase and an organic phase. Once the compound is fully equilibrated with the two solvents, the partition coefficient can be calculated by dividing the amount of compound present in the organic phase by the amount of compound present in the aqueous phase and applying the logarithms. As discussed above, eprinomectin has a low log P value of about 4.4 when compared to other known macrocyclic lactones, and consequently has a low residence time or half-life after injection to non human mammals.

[0036] As will become evident from the following examples, a surprisingly higher half life of around 12 days has been obtained by subcutaneous injection of the eprinomectin composition according to the present invention.

[0037] By "injectable formulation" or "injectable composition" is meant a formulation or composition that can be drawn into a syringe and injected subcutaneously, intravenously, intraperitoneally, or intra-muscularly into a non human mammals without causing adverse effects. According to a preferred embodiment of the present invention, the eprinomectin veterinary composition is administered to the non human mammals by subcutaneous injections.

[0038] As used herein "bioavailability" means the extent or rate at which an active agent is absorbed into a living system or is made available at the site of physiological activity. For active agents that are intended to be absorbed into the bloodstream, bioavailability data for a given formulation may provide an estimate of the relative fraction of the administered dose that is absorbed into the systemic circulation. "Bioavailability" can be characterized by one or more pharmacokinetic parameters.

[0039] "Pharmacokinetic parameters" describe the in vivo characteristics of an active agent over time, such as plasma concentration (C), C_ms, C_n, C₂₄, T_max, and AUC. "C_max" is the measured plasma concentration of the active agent at the point of maximum, or peak, concentration. "C_mi_n" is the measured plasma concentration of the active agent at the point of minimum concentration. "AUC" is the area under the curve of a graph of the measured plasma concentration of an active agent, measured from one time point to another time point. For example AUCo-_t is the area under the curve of plasma concentration versus time from time 0 to time t, where t can be the last time point with measurable plasma concentration for an individual formulation. The AUCo-_∞ or AUC_O-_INF is the calculated area under the curve of plasma concentration versus time from time 0 to time infinity. In steady-state studies, AUCo-x is the area under the curve of plasma concentration over the dosing interval (ie_., from time 0 to time τ (tau), where tau is the length of the dosing interval. Other pharmacokinetic parameters are the parameter K_e or Kei, the terminal elimination rate constant calculated from a semi-log plot of the plasma concentration versus time curve; Ti_/2 the terminal elimination half-life, calculated as 0.693/Kei; CL/F denotes the apparent total body clearance after administration, calculated as Total Dose/Total AUC_∞; and V_area F denotes the apparent total volume of distribution after administration, calculated as Total Dose/(Total AUC_∞xK_ei).

[0040] As used herein "T_max" refers to the observed time (days) for reaching the maximum concentration of the eprinomectin drug in plasma of an animal after injection to the non human mammals.

[0041] As used herein "peak concentration" (C_max) of eprinomectin in a blood plasma", "area under curve (AUC) of eprinomectin in a blood plasma", "half life of eprinomectin (Ti_/2) in blood plasma" are pharmacokinetic parameters known to one skilled in the art. (Pharmaceutical Research, Volume 8, Number 4 / April, 1991 Laursen et al., Eur. J. Endocrinology, 135: 309-315, 1996).

[0042] The "area under curve (AUC)" measures the concentration of eprinomectin in a blood serum of a subject within time after administration of a dosage of eprinomectin to the subject either by injectable route. "C_max" is the maximum concentration of eprinomectin in the blood serum of a subject following a single dosage of eprinomectin to the subject.

[0043] As used herein, "about" will be understood by a person of ordinary skill in the art and will vary to some extent on the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art given the context in which it is used, "about" will mean up to plus or minus 10% of the particular term. [0044] In the formula according to the present invention, the drug eprinomectin in association with PEG has improved bioavailability and increased residence time which results in slow release of the drug or provides a long lasting effect of the drug. Thus, the drug's antiparasitic effect lasts for a longer period due to its presence in the blood. Further, it has been established that there is lesser variation of eprinomectin plasma concentrations which translates into a better efficacy in the herd as well as a less risk of inducing any resistance. [0045] The veterinary eprinomectin composition for parenteral administration to non human mammals, delivers less than about 0.5 mg/kg of eprinomectin, and preferably less than about 0.4mg/kg, or between about 0.1 to about 0.4mg/kg. Preferably, the eprinomectin dose within the composition ranges between about 0.1 to 0.3 mg/kg and about 0.3 mg/kg and is about 0.2mg/kg. The required dosage of the injectable veterinary composition is thus lower than dosage for current pour on formulations. Indeed, as indicated above, the recommended eprinomectin subcutaneous dose is about 0.2mg/kg. In one embodiment such dosages are administered to the animal only once (as a single administration) in an interval period of 40 days without any other doses of eprinomectin being given in this period. This is less compared to 14, 21, 28 days for the pour-on or subcutaneous formulations of eprinomectin and ivermectin.

[0046] The injectable veterinary eprinomectin formulations according to the present invention exhibits an elevation in the peak plasma concentration (C_max) of eprinomectin and an increase in the area under the plasma curve (AUC) over time and further a superior half life (Ti_/2) as compared to current macrocyclic lactone formulations. The increase in C_max and AUC leads to a greater efficiency of the macrocyclic lactone composition of the invention and allows lower doses to be administered and can still be effective in removing parasites. [0047] In a preferred embodiment, the methods and compositions of the present invention are characterized by: (i) a peak concentration (C_max) of eprinomectin in blood plasma of said non human mammals of about 45 to about 75 ng/mL, or about 45 to about 60 ng/niL, and preferably about 50 ng/niL; (ii) an area under concentration curve (AUC) of eprinomectin in blood plasma of said non human mammals of about 7000 to about 9000 (ng/ml)xh, or about 8000 to about 8500 (ng/ml)xh, and preferably about 8300 (ng/ml)xh; (iii) the half life (Ti_/2) of eprinomectin in blood plasma is about 10-15 days, or 11-13 days, and preferably at least 12 days; and/or (iv) a T_max greater than 1.5 days, or about 2 to 3 days, and preferably about 2.5 or 2.3 days. Methods of measuring concentration eprinomectin in blood plasma are well known to skilled person in the art and are described in the Examples below using a previously published method (Danaher and al., "Development and optimization of an improved derivatisation procedure for the determination of avermectins and mylbemycins in bovine liver", The Analyst, 126, 576- 580).

[0048] These enhanced rates and levels of delivery are correlated with increased therapeutic efficacy of the methods and formulations of the invention for prophylaxis and/or treatment of the indicated parasitic diseases and conditions in non human mammals.

[0049] The present invention thus provides a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin, a PEG solvent and optionally other solvents and excipients, wherein eprinomectin active compound has an enhanced bioavailability and a greater half-life (Ti_/2) as shown in the Examples and/or when compared to known macrocyclic lactone, such as ivermectin, doramectin, and moxidectin. [0050] Formulations of the present invention may be sterile and/or non-sterile injectable formulations. For instance, the formulation may be an aqueous or oleaginous suspension. The suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The injectable formulation may also be a sterile injectable solution or suspension in a non- toxic parenterally acceptable diluent or solvent. Suitable diluents and solvents for injectable formulations include 1,3-butanediol, water, Ringer's solution and isotonic sodium chloride solution. Sterile, fixed oils are conventionally employed as a solvent or suspending medium. Suitable fixed oils include, but are not limited to, synthetic mono-or di-glycerides; fatty acids, such as oleic acid and its glyceride derivatives; and natural pharmaceutically- acceptable oils, such as olive oil, castor oil, and polyoxyethylated derivatives thereof (Sigma Chemical Co.; Fisher Scientific).

[0051] In addition, the injectable formulation may further include one or more additional anti-parasitic agents, such as without any limitations, salicylanilides compounds, avermectins, and/or mylbemicins. [0052] Furthermore, the injectable formulation may further include any of the following many other ingredients in a pharmaceutically acceptable amount such as, for example, one or more protective light stabilizers, crystallization inhibitors, colloids, adhesives, thickeners, thixotropic agents, penetrating agents, stabilizers, sequestering antioxidants, solubilizing agents, fluidizing agents, complexing agents, vitamins, minerals, preservatives, buffering agents, antiseptic agents or a combination thereof. More generally, the active ingredients may be combined with any solid or liquid additives corresponding to the usual techniques of formulation development. Examples of antioxidants include without limitation, sulfate compounds, L-cysteine, thiodipropionic acid, thiolactic acid, monothioglycerol, propyl galate sodium metabisulfite, sodium formaldehyde, sulfoxylate acetate, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), vitamin E, ascorbic acid (vitamin C), vitamin B12, or a combination of these agents. Illustrative thickening agents include methylcellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, polyvinylpyrrolidone, and mixtures thereof. Illustrative complexing agents include EDTA and salts thereof, phosphate, nitrate, acetate, citrate, and mixtures thereof. Illustrative antiseptics include methyl p-oxybenzoate, propyl p-oxybenzoate, PHB ester, chlorobutanol, benzyl alcohol, butanol, butane- 1, 3 -diol, chlorohexidin salts, benzoic acid and its salts, sorbic acid, and mixtures thereof. [0053] The formulations of the present invention can be administered to non human mammals, especially mammals, including, but not limited to ruminant mammals, e.g., bovines or ovines, more generally cows, sheep, goats, buffaloes, oxen, bulls, horses, pigs, cats, dogs, hamsters, mice, rats, monkeys, rabbits, deers, llamas, and yaks, and more particularly dairy and/or breeding cattle such as cows and goats. In a preferred embodiment, the non human mammals are bovines. In most preferred embodiments, the non human mammals are milking cows or lactating cows or dairy cows.

[0054] The present invention further relates to a veterinary composition comprising a therapeutically effective amount of eprinomectin and PEG as solvent, optionally with other solvents and excipients, for parenteral administration to bovines, more specifically for dairy cows, in such a manner that less residues of macrocyclic lactone, particularly eprinomectin, are found in the milk or in the meat and offal of cows as compared to pour on applications.

[0055] In effect, a surprising feature of the invention is that after administration of the eprinomectin injectable veterinary formulation according to the present invention, the cows continue milking without delay with less residues of macrocyclic lactone in milk.

[0056] The present invention also relates to a veterinary injectable composition comprising a therapeutically effective amount of eprinomectin and PEG as solvent, optionally with other solvents and excipients, for controlling a broad range of endoparasites and ectoparasites in non human mammals. Such eprinomectin formulations are thus particularly useful for treating and/or preventing infections caused by endoparasites and/or ectoparasites in non human mammals, particularly in dairy cattle. Thus the formulation may be given to a healthy animal for the purpose of preventing a parasitic infection. The formulation may be given to an animal that is already infected, such as an animal that has suffered weight loss due to the infection.

[0057] In various embodiments, the compositions used in the methods of the invention may further comprise a second pharmaceutically active compound. Representative classes of second pharmaceutically active compounds include, but are not limited to, other antibacterials, antifungals, antiparasitics, antivirals, and antiinflammatories. [0058] Compositions and methods according to the present invention are particularly effective for controlling digestive and pulmonary strongyles and ectoparasites.

[0059] In a further aspect, the present invention relates to a method of treating and/or preventing infections caused by endoparasites and/or ectoparasites, which comprises administering to non human mammals an effective amount of an anti-parasitic formulation as described herein.

[0060] According to this aspect, mammals which may be treated include, but are not limited to ruminant mammals, e_^g_., bovines or ovines, more generally cows, sheep, goats, buffaloes, oxen, bulls, horses, pigs, cats, dogs, hamsters, mice, rats, monkeys, rabbits, deers, llamas, and yaks, and more particularly dairy and/or breeding cattle. In most preferred embodiments the non human mammal is a milking cow or goat. [0061] In another embodiment for treatment against ectoparasites, the ectoparasite may be one or more insect or arachnid including those of the genera Ctenocephalides, Rhipicephalus, Dermacentor, Ixodes, Ambylomma, Haemaphysalis, Hyalomma, Sarcoptes, Psoroptes, Otodectes, Chorioptes, Hypoderma, Damalinia, Linognathus, Haematopinus, Solenoptes, Trichodectes, and Felicola.

[0062] In yet another embodiment for the treatment against ectoparasites, the ectoparasite is from the genera Ctenocephalides, Rhipicephalus, Dermacentor, Ixodes and/or Boophilus. The ectoparasites treated include but are not limited to fleas, ticks, mites, mosquitoes, flies, lice, blowfly and combinations thereof. Specific examples include but are not limited to cat and dog fleas (Ctenocephalides felis, Ctenocephalides sp. and the like), ticks (boophilus sp., Ixodes sp., Dermacentor sp., Amblyoma sp. and the like), and mites (Demodex sp., Sarcoptes sp., Otodectes sp. and the like), lice (Trichodectes sp., Cheyletiella sp., Lignonathus sp., and the like), mosquitoes (Aedes sp., Culux sp., Anopheles sp., and the like) and flies (Hematobia sp., Musca sp., Stomoxys sp., Dematobia sp., Coclyomia sp., and the like). In yet another embodiment for the treatment against ectoparasites, the ectoparasite is a flea and/or tick. [0063] Additional examples of ectoparasites include but are not limited to the tick genus Boophilus, especially those of the species microplus (cattle tick), decoloratus and anulatus; myiases such as Dermatobia hominis (known as Berne in Brazil) and Cochlyomia hominivorax (greenbottle); sheep myiases such as Lucilia sericata, Lucilia cuprina (known as blowfly strike in Australia, New Zealand and South Africa), flies whose adult constitutes the parasite, such as Haematobia irritans (horn fly); lice such as Linognathus vitulorum, etc.; and mites such as Sarcoptes scabici and Psoroptes ovis. The above list is not exhaustive and other ectoparasites are well known in the art to be harmful to animals and humans. These include, for example migrating dipterous larvae.

[0064] The composition can also be used to treat against endoparasites such as those helminths selected from the group consisting of Anaplocepheda, Ancylostoma, Anecator, Ascaris, Capillaria, Cooperia, Dipyllidinum, Dirofilaria, Echinococcus, Enterobius, Fasciola, Haemonchus, Oesophagostumum, Ostertagia, Toxocara, Strongyloides, Toxascaris, Trichinella, Trichuris, and Trichostrongylus . Specifically bots, strongyles, ascarids and pinworms, roundworms like Wirewormf Haemonchus placet), Brown stomach worm (Ostertagia spp.), Nodular worm (Oesophagostomum spp.), Hookworm (Bunostomum spp.), Bankrupt worm (Cooperia spp.), Parafilaria bovicola( a/se bruising), tapeworms like milk tapeworm (Moniezia spp.). Flukes, ihis group includes liver fluke species (Fasciola spp. - liver fluke and giant liver fluke) and conical fluke (Calicophoron - formerly Paramphistomum) the latter which occur in the gastrointestinal tract.

[0065] Further with or without the addition of additional pesticidal agents the composition of the invention can also be used to treat other pests which include but are not limited to pests:

from the order Isopoda, for example Oniscus asellus, Armadillidium vulgare and Porcellio scaber;

from the order Diplopoda, for example Blaniulus guttulatus;

from the order Chilopoda, for example Geophilus carpophagus and Scutigera spp.;

from the order Symphyla, for example Scutigerella immaculata; from the order Thysanura, for example Lepisma saccharina;

from the order Collembola, for example Onychiurus armatus;

from the order Orthoptera, for example Acheta domesticus, Gryllotalpa spp., Locusta migratoria migratorioides, Melanoplus spp. and Schistocerca gregaria; from the order Blattaria, for example Blatta orientalis, Periplaneta americana, Leucophaea maderae and Blattella germanica;

from the order Dermaptera, for example Forficula auricularia;

from the order Isoptera, for example Reticulitermes spp.;

from the order Phthiraptera, for example Pediculus humanus corporis, Haematopinus spp., Linognathus spp., Trichodectes spp. and Damalinia spp.;

from the order Thysanoptera, for example Hercinothrips femoralis, Thrips tabaci, Thrips palmi and Frankliniella accidentalis;

from the order Heteroptera, for example Eurygaster spp., Dysdercus intermedins, Piesma quadrata, Cimex lectularius, Rhodnius prolixus and Triatoma spp.;

from the order Homoptera, for example Aleurodes brassicae, Bemisia tabaci, Trialeurodes vaporariorum, Aphis gossypii, Brevicoryne brassicae, Cryptomyzus ribis, Aphis fabae, Aphis pomi, Eriosoma lanigerum, Hyalopterus arundinis, Phylloxera vastatrix, Pemphigus spp., Macrosiphum avenae, Myzus spp., Phorodon humuli, Rhopalosiphum padi, Empoasca spp., Euscelis bilobatus, Nephotettix cincticeps, Lecanium corni, Saissetia oleae, Laodelphax striatellus, Nilaparvata lugens, Aonidiella aurantii, Aspidiotus hederae, Pseudococcus spp. and Psylla spp.; from the order Lepidoptera, for example Pectinophora gossypiella, Bupalus piniarius, Cheimatobia brumata, Lithocolletis blancardella, Hyponomeuta padella, Plutella xylostella, Malacosoma neustria, Euproctis chrysorrhoea, Lymantria spp., Bucculatrix thurberiella, Phyllocnistis citrella, Agrotis spp., Euxoa spp., Feltia spp., Earias insulana, Heliothis spp., Helicoverpa spp., Mamestra brassicae, Panolis flammea, Spodoptera spp., Trichoplusia ni, Carpocapsa pomonella, Pieris spp., Chilo spp., Pyrausta nubilalis, Ephestia kuehniella, Galleria mellonella, Tineola bisselliella, Tinea pellionella, Hofmannophila pseudospretella, Cacoecia podana, Capua reticulana, Choristoneurafumiferana, Clysia ambiguella, Homona magnanima, Tortrix viridana and Cnaphalocerus spp.; from the order Coleoptera, for example Anobiur punctatum, Rhizopertha dominica, Bruchidius obtectus, Acanthoscelides obtectus, Hylotrupes bajulus, Agelastica alni, Leptinotarsa decerlineata, Phaedon cochleariae, Diabrotica spp., Psylliodes chrysocephala, Epilachna varivestis, Atomaria spp., Oryzaephilus surinamensis, Anthonomus spp., Sitophilus spp., Otiorrhynchus sulcatus, Cosmopolites sordidus, Ceuthorrhynchus assimilis, Hypera postica, Dermestes spp., Trogoderma spp., Anthrenus spp., Attagenus spp., Lyctus spp., Meligethes aeneus, Ptinus spp., Niptus hololeucus, Gibbiur psylloides, Tribolium spp., Tenebrio molitor, Agriotes spp., Conoderus spp., Melolontha melolontha, Amphimallon solstitialis and Costelytra zealandica;

from the order Hymenoptera, for example Diprion spp., Hoplocampa spp., Lasius spp., Monomorium pharaonis and Vespa spp.;

from the order Diptera, for example Aedes spp., Anopheles spp., Culex spp., Drosophila melanogaster, Musca spp., Fannia spp., Calliphora erythrocephala, Lucilia spp., Chrysomyia spp., Cuterebra spp., Gastrophilus spp., Hyppobosca spp., Stomoxys spp., Oestrus spp., Hypoderma spp., Tabanus spp., Tannia spp., hortulanus, Oscinella frit, Phorbia spp., Pegomyia hyoscyami, Ceratitis capitata, Dacus oleae, Tipula paludosa, Hylemyia spp. and Liriomyza spp.;

from the order Siphonaptera, for example Xenopsylla cheopis and Ceratophyllus spp.;

^ from the class of arachnids, for example Scorpio maurus, Latrodectus mactans, Acarus siro, Argas spp., Ornithodoros spp., Dermanyssus gallinae, Eriophyes ribis, Phyllocoptruta oleivora, Boophilus spp., Rhipicephalus spp., Amblyomma spp., Hyalomma spp., Ixodes spp., Psoroptes spp., Chorioptes spp., Sarcoptes spp., Tarsonemus spp., Bryobia praetiosa, Panonychus spp., Tetranychus spp., Hemitarsonemus spp. and Brevipalpus spp. EXAMPLES

Example 1 - Preparation of injectable veterinary formulation of eprinomectin

The injectable veterinary eprinomectin composition was prepared by mixing following components as showed in the Table 1 below:

Table 1:

Example 2- Comparison of pharmacokinetic properties of the formulation of current invention versus current formulations

Table 2:

Inj 14.5 5.4 5.0 12.2

PO - 9.82 5.3 -

MRT(days)

Inj 25.7 11.80 5.4 12

PO 12.8 12.8 8.4 -

AUCO-inf ((ng/ml)xh) 6 719 / 549.6 12 264 / 4 334 6 384 / 2 919 8 326 / -

Sources Alvinerie et al, J Toutain et al, Lifschitz et al, Example 1

Vet Pharmacol Vet Parasitol. Vet Parasitol.

Ther. 1997 1997 2007 Jul

Apr;20(2):91-9. Sep;72(l):3-8. 20; 147(3-

Sallovitz et al, Gayrard et al, 4):303-10.

2000. J. Vet. 1999. Vet Gayrard et al,

Pharmacol. Ther, Parasitol, 81:47- 1999. Vet

23, Supp. 1, 55 Parasitol, 81:47- abstract H17 55

* Inj SC : Subcutaneous Injection: Inj: Inljection; PO: Pour On

The results show that application of a subcutaneous composition of eprinomectin at half the dose compared to a corresponding topical pour on formulation resulted in improved pharmacokinetic results, including greater C_max and/or greater bioavailability (AUC) of the eprinomectin.

Example 3 - Determination of pharmacokinetic data

The injectable eprinomectin composition which is designated EPRINOJECT was administered to 5 lactating cows. Blood samples of 10ml were collected by venepuncture of the anterior caval vein into heparinized tubes before treatment, and 6, 12, 24, 40, 48, 60 hours, 3, 5, 7, 11, 16, 21, 25, 35 and 43 days after treatment. The samples were centrifuged immediately at 10000 rpm for 10 min. Eprinomectin concentrations in blood plasma were determined by a validated HPLC method following derivatisation and applying fluorescence detection. The results are provided in the following Table 3. In particular, the ratio in the table 3: these values stand for the ratio between Pour-on/Injection. The t_max are equivalent (ratio = 0.8), the Cmax is 2.4 times higher with injection, AUC is 3 times higher with injection.

Table 3: Pharmacokinetic parameters

EPRINOJECT

Parameters (Unit) Mean ± SD Ratio

tmax (h) 55 ± 11 0.8

c ^max (ng/mL) 47.8 ± 9.58 2.4

AUCo (h* ng/mL) 7783 ± 1703 3.0

AUCo (h* ng/mL) 8309 ± 1775 3.1

Residence

(h) 300 ± 72

time

Also, the time above 1 ng/mL for eprinomectin calculated after single subcutaneous administration of 200 g kg of eprinomectin injectable composition of the present invention is provided in the following Tables 4.1 and 4.2.

Table 4.1 : Individual values

Table 4.2: Statistics

Example 4 - Comparative study with eprinomectin pour-on formulation

(Eprinex®= EPRINEX)

The veterinary eprinomectin composition according to the present invention (EPRINOJECT) was prepared as showed in the Example 1 hereabove.

Lactating dairy cows (10 in total, 5 per group) were divided into 2 treatment groups. Group 1 received EPRINEX (Merial), Pour-on, 500 g kg BW, and group 2 received EPRINOJECT, Subcutaneous, 200 μg/kg BW.

Blood samples (10 mL) were collected by venepuncture of the anterior caval vein into heparinized tubes before treatment, and 6, 12, 24, 40, 48, 60 hours, 3, 5, 7, 11, 16, 21, 25, 35 and 43 days after treatment. The samples were centrifuged immediately at 10000 rpm for 10 min.

Eprinomectin concentrations in blood plasma were determined by a validated HPLC method following derivatization and applying fluorescence detection using a previously published method (Danaher and al., "Development and optimization of an improved derivatisation procedure for the determination of avermectins and mylbemycins in bovine liver", The Analyst, 126, 576-580).

The results are provided in the following Table 5 and in Figures 1 and 2.

Table 5 : Pharmacokinetic parameters

Parameters (Unit) Mean ± SD

Ratio

EPRINOJECT EPRINEX

tmax (h) 55 ± 11 70 ± 30 0.8

Cmax (ng/mL) 50.3 ± 12.2 20.33 ± 10.34 2.4

AUCo (h*ng/mL) 7799 ± 1698 2538 ± 1211 2.07

AUCo (h* ng/mL) 8326 ± 1772 2677 ± 1177 3.1

MRT (h) 299 ± 72 299 ± 85 - Also, the time above 1 ng/mL for eprinomectin calculated after single subcutaneous administration to cows of 200 g kg of EPRINOJECT, composition of the present invention, is provided in the following Tables 6.1 and 6.2.

Table 6.1 : Individual values

Table 6.2 : Statistics

Also, the time above 1 or 2 ng/mL for eprinomectin calculated after topical application of a single dose of 500 g kg of eprinomectin as EPRINEX pour-on in cows are provided in the following Tables 7.1 and 7.2.

Table 7.1 : Individual values

Table 7.2 : Statistics

Claims

1. An injectable parasiticide veterinary composition, comprising a therapeutically effective amount of a poorly lipophilic macrocyclic lactone and a solvent system comprising polyethylene glycol, optionally with other solvents and excipients.

2. The composition according to claim 1, wherein the macrocyclic lactone has a partition coefficient or log P lesser than about 5, or from about 4 to about 5, or about 4.5 or about 4.4.

3. The composition according to claim 1 or 2, wherein the macrocyclic lactone is eprinomectin.

4. The composition according to any one of the preceding claims, comprising at least about 20% PEG by weight.

5. The composition of claim 4, comprising between 20 and 98% PEG by weight or between 40 and 95% PEG by weight.

6. The composition of claim 4 or 5, comprising about 93% PEG by weight.

7. The composition according to any one of the preceding claims, wherein the solvent system further comprises a combination of benzyl alcohol and N-methyl pyrrolidone.

8. The composition according to any one of the preceding claims, further comprising a pharmaceutically acceptable vehicle selected from the group consisting of propylene glycol, glycerol formal, isosorbid dimethyl ether, ethanol, dimethyl sulfoxide, tetrahydrofufuryl alcohol, triacetin, and combinations thereof.

9. The composition according to any one of the preceding claims, wherein the solvent system is present in an amount sufficient to yield bioavailability and a long lasting effect of the eprinomectin.

10. The composition according to any one of the preceding claims, comprising the about 0.5 to about 5 % of eprinomectin, about 0.5 to about 5 % of benzyl alcohol, about 0.5 to about 5 % N-methyl pyrrolidone, and is formulated in polyethylene glycol.

11. The composition according to claim 10, comprising about 1 % of eprinomectin, about 1 % of benzyl alcohol, about 5 % of N-methyl pyrrolidone, and is formulated in polyethylene glycol.

12. The composition according to any one of the preceding claims, further comprising one or more anti-parasitic agents, such as salicylanilides compounds, avermectins and/or mylbemicins.

13. The composition according to any one of the preceding claims, further comprising one or more solid or liquid additives chosen from amongst protective light stabilizers, crystallization inhibitors, colloids, adhesives, thickeners, thixotropic agents, penetrating agents, stabilizers, sequestering antioxidants, solubilizing agents, fluidizing agents, complexing agents, vitamins, minerals, preservatives, buffering agents, antiseptics agents and combinations thereof.

14. The composition according to claim 13, wherein the antioxidant is chosen from amongst sulfate compounds, L-cysteine, thiodipropionic acid, thiolactic acid, monothioglycerol, propyl galate sodium metabisulfite, sodium formaldehyde, sulfoxylate acetate, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), vitamin E, ascorbic acid (vitamin C), vitamin B12, and combinations thereof.

15. The composition according to any one of the preceding claims, for treating and/or preventing infections caused by endoparasites and/or ectoparasites in non human mammals.

16. The composition according to claim 15, for treating and/or preventing digestive and/or pulmonary strongyles in non human mammals.

17. The composition according to claim 15 or 16, wherein said non human mammals are bovines or ovines.

18. The composition according to any one of claims 15-17, wherein said non human mammals are cows, sheep, goats, buffaloes, oxen, bulls, horses, pigs, cats, dogs, hamsters, mice, rats, monkeys, rabbits, deers, lamas, or yaks.

19. The composition according to any one of claims 15-18, wherein said non human mammals are cattle or breeding cattle.

20. The composition according to any one of claims 15-19, wherein said non human mammals is a dairy cow or dairy goat.

21. The composition according to any one of claims 15-20, wherein said composition is administered to said non human animal as a single administration within an interval period of 40 days.

22. The composition according to any one of the claims 15-21, wherein said composition is administered to said non human mammals via subcutaneous injection.

23. The composition according to any one of the preceding claims, characterized by (i) a peak concentration (C_max) of eprinomectin in blood plasma of said non human mammals of about 45 to about 75 ng/mL, or about 45 to about 60 ng/mL, and preferably about 50 ng/mL; (ii) an area under concentration curve (AUC) of eprinomectin in blood plasma of said non human mammals of about 7000 to about 9000 (ng/ml)xh, or about 8000 to about 8500 (ng/ml)xh, and preferably about 8300 (ng/ml)xh; (iii) the half life (T1/2) of eprinomectin in blood plasma is about 10-15 days, or 11-13 days, and preferably at least 12 days; and/or (iv) a T_max greater than 1.5 days, or about 2 to 3 days, and preferably about 2.5 or 2.3 days.

24. A method of treating and/or preventing infections caused by endoparasites and/or ectoparasites in non human mammals comprising injecting to said animals the composition of any one of the preceding claims.

25. The method according to claim 24, wherein said composition is administered to said non human animal as a single administration within a period within an interval period of 40 days.

26. The method according to claim 24 or 25, wherein the injection is a subcutaneous injection.

27. The method according to any one of claims 24-26, wherein the eprinomectin composition is injected to said human mammals in an effective dose of less than about 0.5 mg/kg.

28. The method according to claim 27, wherein the effective dose of eprinomectin is about 0.2 mg/kg.