MXPA97007257A - A parasiticide composition injectable long and procedure to prepare - Google Patents

Abstract

A long-acting injectable parasiticide composition comprising ivermectin in a concentration of 1% (w / w), benzyl alcohol, polyvinylpyrrolidone, N-methyl-2-pyrrolidone in a proportion between 40-65% / v / w is described) of the total and adyuvant

Description

AN INJECTABLE PARASITICIZE COMPOSITION OF LONG ACTION AND PROCEDURE TO PREPARE IT The object of the present invention is a new long-acting injectable parasiticide composition and the process for preparing it.

Ivermectin is a semisynthetic derivative consisting of a mixture of two components, 22.23 dihydroavermectin Bla and 22.23 dihydroavermectin Blb. The starting avermectin B1 is a macrocyclic lactone obtained from the fermentation broth cultures of Streptomyces avermitilis and the selective hydrogenation of the double bond existing at the C22-C23 positions of the macrolide structures of avermectin Bx leads to the synthesis of ivermectin, such as It is described in the literature.

Ivermectin, a macrocyclic lactone, whose formula developed is where R2 is isopropyl (20%) or sec-butyl (80%), it is a broad spectrum antiparasitic not only against internal parasites, but also against external parasites and even endoparasitic stages of some arthropods. It is active against genera of nematodes that affect domestic animals and livestock such as those of the superfamilies Trichostrongyloidea, Strongyloidea, Metastrongyloidea, Rhabditoidea, Asearidoidea, Oxyuroidea, Spiruroidea, Filaroidea and Trichurioidea. Its great liposolubility, high penetration in the organism and long half-life, explain the wide use of ivermectin as an anthelmintic.

The oral route has been the usual one for the administration of antiparasitic drugs to large animals. Patents EP 473223, EP 537000, EP 537998, US 4,440,740 describe solid formulations of ivermectin.

Highly effective injectable formulations have also been described and the practicality of their application caused the appearance of a series of preparations, for example those described in the following patents, which relate to liquid administration forms: EP 146414, EP 413538, EP 535734, EP 538750 and US 4,389,397.

In particular, in patent EP 146414, certain liquid, non-aqueous formulations containing ivermectin and more specifically, those containing 1% ivermectin in a vehicle formed by a mixture of 40% glycerol formal - 60% propylene glycol.

An inventive long-acting injectable parasiticidal composition containing ivermectin, which exhibits pharmacokinetic properties comparatively superior to known formulations, is an object of the present invention.

Said novel injectable long-acting injectable composition also has acceptable levels of residuality for the consumption of meat by humans, in conditions of total safety. The European Union has established for ivermectin in cattle the maximum residual amounts of 100 μg / kg in liver and 40 μg / kg in fat.

Likewise, the object of the present invention is a method of preparing said novel long-acting injectable parasiticidal composition.

It is therefore the object of the present invention an injectable composition long-acting injectable, comprising ivermectin in sufficient quantity to achieve a final concentration of about 1% (w / w), benzyl alcohol, polyvinylpyrrolidone, N-methyl-2 pyrrolidone in a proportion between 40-65% (v / p) of the total formulation and glycerin to complete the final 100% of the weight.

In addition to these components, the formulation may contain stabilizers / antioxidants, such as thiodipropionic acid, acetyl cysteine, cysteine, sodium metabisulfite, EDTA, sodium EDTA, sodium citrate, N-propyl gallate, butyl-hydroxytoluene, or a mixture of two or more of one of these products, in a proportion of 0.01 to 2% w / w. Also optionally the formulation may include a colorant, for example, Beta-carotene, in a proportion of 0.005-0.05 w / w.

Another object of the present invention is the process for preparing the long-acting injectable parasiticidal composition, which comprises mixing ivermectin in an amount sufficient to achieve a final concentration of about 1% (w / w) with benzyl alcohol and polyvinylpyrrolidone, followed by addition of the mixture to N-methyl-2-pyrrolidone, the latter in a proportion of between 40-65% (v / p) of the total formulation. Then add the antioxidant or mixture of antioxidants dissolved in water if necessary. The mixture is stirred until total dissolution and glycerin is added until reaching 100% final weight.

The polyvinylpyrrolidone "which has been used in the composition of the invention is Kollidon K 17 PF, with a value of K of 16-18 and a relative viscosity of solution in 5% distilled water of 1,250-1,370. Preferably, Kollidon K 17 PF is used in a proportion of between 7-11% (w / w) of the total mixture.

The benzyl alcohol is incorporated into the mixture in a suitable proportion to reach a final concentration of between 1.5 and 2% (w / w).

The following examples are intended to illustrate the invention for better understanding without intending to introduce limitations.

EXAMPLE 1: Preparation of the composition In a stainless steel vessel, 1,000 g of Ivermectin, 8,977 g of Kollidon K 17 PF, and 1,795 g of benzyl alcohol are dissolved in 53,860 ml of N-Methyl-2-pyrrolidone.

(Pharmasolve). 0.03 g of N-propyl gallate is then added. The mixture is stirred until total dissolution. It is brought to 100,000 g with glycerin. The solution obtained is pre-filtered and finally filtered on a Nylon 66 or Teflon end filter with a pore diameter of 0.45 microns.

EXAMPLE 2: Pharmacokinetic Behavior of a Composition of Ivermectin at 1% w / w in N-methyl-2-pyrrolidone and polyvinyl pyrrolidone prepared according to Example 1 Six healthy Holstein Argentine bovine animals, castrated males, of a weight between 150-200 kg. The animals were dewormed with a benzoimidazole 20 days before the start of the test.

The composition of Example 1 was administered to the animals subcutaneously at a rate of 1 ml per 50 kg of weight. Blood samples were taken in heparinized syringes, prior to administration and, subsequently, at the following times: 0, 5, 1,2, 3, 4, 5, 6, 7, 8, 10, 12, 15, 20, 25 and 30 days. The plasma was separated by centrifugation and saved until its assay. The test was performed by high pressure liquid chromatography with ultraviolet detection. For this, the samples were treated by solid liquid extraction in C18 cartridges. After this process they were injected into the chromatograph. The percentage of ivermectin extraction was 80%. The level of quantification of the method was 0.5 ng / ml. The repeatability had a variability of less than 2% for a concentration of 5 ng / ml. The pharmacokinetic analysis was performed by means of a linear regression program called Strip (Brown and Manno, 1978). The pharmacokinetic parameters were obtained by classical methods.

The concentrations of ivermectin as a function of time are presented in Table I. The plasma profile of ivermectin can be seen in Figure 1, where concentration versus time has been represented. The area under the curve (ABC), which in this case is of the order of 300, indicates what percentage of the dose actually reaches plasma and contributes to the pharmacological action. The pharmacokinetic parameters are presented in Table II.

The results obtained show higher plasma peaks and longer lasting plasma concentrations than in the classic preparations of ivermectins, such as those formulated in propylene glycol-glycerol formal mentioned above. In the present case, an average maximum concentration (Cmax) of the order of 30 ng / ml has been found (Table I, day 3) and an ABC of the order of 300 (Figure 1). But the most differential characteristic with respect to the aforementioned known formulations is found in the elimination half-life (TI / 2 ß in Table II), which in this experience gave an average of almost 9 days, unlike the known formulations with elimination half-lives of order 5-6 days. Likewise, the concentrations at day 30 in this experiment give an average of 2.81 ng / ml, while they are of the order of 1 ng / ml for the aforementioned classical compositions.

Table I: Plasma concentrations of ivermectin after administration of a formulation at 1% w / w in N-methyl-2-pyrrolidone and polyvinyl pyrrolidone to 6 young cattle at a rate of 1 ml per 50 kg.

Table II. Pharmacokinetic parameters for a preparation of ivermectin at 1% w / w in N-methyl-2-pyrrolidone and polyvinyl pyrrolidone in six young cattle, after subcutaneous administration.

EXAMPLE 3: Determination of ivermectin residues after administration of a 1% w / w Ivermectin composition in N-methyl-2-pyrrolidone and polyvinyl pyrrolidone prepared according to Example 1. 21 calves between 100-150 kg were separated. The composition of Example 1 was administered subcutaneously at a rate of 1 ml per 50 kg of weight. From day 0 (administration) 3 animals were sacrificed weekly from 3 weeks to 9 weeks.

Samples of plasma, liver, fat, muscle, muscle injected area and kidney were taken.

Samples of 5 g were homogenized in Ultra-Turrax at 2 minutes with 15 ml of acetonitrile. The homogenate was centrifuged for 5 min at 300 rpm. 15 ml of supernatant were transferred to flasks and diluted with water to a 70% aqueous solution. 50 μ of triethylamine was added.

C8 bond-Elut cartridges were activated with acetonitrile and acetonitrile: water (30:70). The total sample was passed through the C8 cartridge. The cartridge was eluted with 5 ml of acetonitrile and the eluate evaporated under nitrogen. The residue was resuspended in 1 ml of methanol. An aliquot of 500 μl was transferred to a silanized tube and evaporated. 100 μ of the derivatizing agent (1-methyl-imidazole-acetic anhydride-dimethylformamide (2: 6: 9) was added and the tube was baked at 95 ° C for one hour, after cooling, 1 ml of chloroform was added, vortexed and transferred to Sep-Pack cartridges The cartridge was eluted with 9 ml of chloroform, evaporated and resuspended in 500 μl of methanol and injected into the high pressure liquid chromatography system with fluorometric detection (HPLC) .The chromatographic conditions were: Mobile phase: acetonitrile: water (97: 3), flow: 1 ml / min, excitation: 364 nm.

The results are expressed in ppb as averages of the concentrations observed in each trio of animals, in Table III.

According to the residual limits established by the European Union, the experimental animals used in this study showed an average of concentrations in the target tissues within the acceptable range for consumption, from 41 days post-administration.

Table III: Concentrations of ivermectin in various tissues and plasma between three and 9 weeks after administration of the composition prepared according to Example 1, in samples of animals treated with 1 ml per 50 kg of weight subcutaneously.

Claims (10)

CLAIMS Having thus specially described and determined the nature of the present invention and the manner in which it is to be put into practice, it is claimed to claim as property and exclusive right:

1. - A long action injectable parasiticide composition characterized in that it comprises ivermectin in a concentration of 1% (w / w), benzyl alcohol, polyvinyl pyrrolidone, N-methyl-2-pyrrolidone in a proportion between 40-65% (v / p) of the total formulation, adjuvants and glycerin until reaching 100% final weight.

2. - A parasiticide composition according to claim 1, characterized in that the concentration of polyvinyl pyrrolidone is from 7 to 11% (w / w).

3. - A parasiticide composition according to claim 1, characterized in that the concentration of the benzyl alcohol is 1.5 to 2% (w / w).

4. - A parasiticide composition according to claim 1, characterized in that the adjuvants are antioxidants / stabilizers.

5. - A parasiticide composition according to claim 1, characterized in that the antioxidants / stabilizers are selected from thiodipropionic acid, acetyl cysteine, cysteine, sodium metabisulfite, EDTA, sodium EDTA, sodium citrate, N-propyl gallate, butyl-hydroxy -tolueno.

6. - Method for preparing an injectable parasiticide composition of ivermectin characterized by comprising mixing ivermectin in sufficient quantity to achieve a final concentration of 1% (w / w) with benzyl alcohol and polyvinyl pyrrolidone, add adjuvants to said mixture, followed by addition of the mixture to N-methyl-2-pyrrolidone, the latter in a proportion of between 40-65% (v / p) of the total formulation; the mixture is stirred until total dissolution and glycerin is added until reaching 100% final weight.

7. - Process according to claim 6, characterized in that the polyvinyl pyrrolidone is incorporated in an amount sufficient to reach a final concentration of between 7 and 11% (w / w).

8. - Process according to claim 6, characterized in that the benzyl alcohol is incorporated in an amount sufficient to reach a final concentration between 1.5 and 2% (w / w).

9. - Process according to claim 6, characterized in that the adjuvants that are added are antioxidants / stabilizers.

10. - Process according to claim 6, characterized in that the antioxidants / stabilizers that are added are selected between thiodipropionic acid, acetyl cysteine, cysteine, sodium metabisulfite, EDTA, sodium EDTA, sodium citrate, N-propyl gallate, butyl- hydroxy-toluene. The benzyl alcohol is incorporated in an amount sufficient to reach a final concentration between 1.5 and 2% (w / w). SUMMARY A long-acting injectable parasiticide composition comprising ivermectin in a concentration of 1% (w / w), benzyl alcohol, polyvinylpyrrolidone, N-methyl-2-pyrrolidone in a proportion between 40-65% / v / w is described) of the total and adjuvants.