RU2847348C1 - Antiparasitic agent for the treatment and prevention of ectoparasites in dogs. - Google Patents

Abstract

FIELD: veterinary medicine.

SUBSTANCE: an insecticide and acaricide intended for oral administration in the form of chewable tablets, containing, by weight: fluralaner - 14-18, dried beef liver - 50-60, microcrystalline cellulose - 4-10, aspartame - 0.1-0.39, macrogol 3350 - 6-10, polyethylene glycol 400 - 1-4, glycerol - up to 100. The product is intended for the prevention of ctenocephalidosis or linoagnathosis, ixodidosis, acarosis and the prevention of infection with S. canis, O. Cynotis and D. Canis. The product is intended for single oral administration. EFFECT: the insectoacaricidal agent provides high and long-lasting therapeutic and prophylactic efficacy, rapid therapeutic action against ectoparasites, safety in a dosage form that is convenient for use in dogs, prevention of re-infection with ectoparasites for 84 days, and is well tolerated by animals.

6 cl, 8 tbl, 8 ex

Description

The invention is intended for the treatment and prevention of arachnoentomoses in dogs. It proposes an insecticidal acaricide based on fluralaner, an isoxazoline, in the form of a chewable tablet with an appealing taste, characterized by rapid release of the active ingredient.

Field of technology to which the invention relates

The invention relates to veterinary medicine, parasitology, veterinary arachnoentomology, and pharmacology, and is intended for the treatment and prevention of ectoparasitosis in dogs. It ensures good palatability, rapid release of the active ingredient, high and long-lasting therapeutic and prophylactic efficacy, ease of use, and safety. The invention is offered as a chewable tablet.

A pressing issue in modern veterinary medicine is finding cost-effective, safe, and effective means for preventing and treating animal ectoparasitoses. In recent decades, new classes of chemical compounds with insectoacaricidal action have been developed and introduced into veterinary practice in various dosage forms: drops for external use, sprays, shampoos, collars, tablets, ointments, etc. Widely used are products based on imidacloprid and fipronil, a class of neonicotinoids and phenylpyrazoles, in the form of solutions for external use. These drugs, as well as others based on juvenile hormone analogues, carbamates, synthetic pyrethroids, usually in the form of complex agents, are effective against canine entomoses and acaroses, allowing for the prevention of re-infestation for about one month after application [2, 4]. The disadvantages of these products are: difficulties in dosing, incorrect application of the drug by owners; possible reduction in effectiveness due to washing the dog, regular swimming in bodies of water, as well as concerns from owners about the impact of the product on family members, including children; the development of cross-resistance in ticks and insects to the widely used fipronil and pyrethroids in combination preparations, as well as the likelihood of developing local skin allergic reactions, systemic neurological disorders and gastrointestinal tract dysfunction [1, 9].

Medicinal products in solid dosage form for oral administration, used in veterinary practice for the treatment and prevention of ectoparasitoses, contain spinosad from the spinosyn group (Comfortis, Elanco), moxidectin from the class of macrocyclic lactones, as part of the drug OkVetExpressTabs, RU 2782929 [13], lufenuron from the class of benzoylamides, as part of the drug Inspector QUADRO, JSC NPF EKOPROM, RU 2657508 [12]. The disadvantage of these products is the fact that spinosad and lufenuron have an insecticidal effect, and when used in combination with moxidectin, toxicity and the risk of side effects increase; in case of generalized demodicosis and ixodidosis, the products are not 100% effective. The use of macrocyclic lactone medications in dog breeds with the MDR1 gene mutation requires special caution and dosage adjustments [8]. One of the disadvantages of the above-mentioned tablets is their poor palatability.

In this regard, a current trend in veterinary pharmacy is the creation of tablets in chewable form that are convenient for feeding and for self-consumption.

The pharmaceutical substances contained in chewable tablets have both local and systemic effects. The advantages of chewable tablets also include the rapid development of the pharmacological effect, ease of use, and high compliance from pet owners. In veterinary medicine, the number of drugs produced in the form of chewable tablets with insectoacaricidal action is limited. These are mainly drugs based on the new class of isoxazolines, which includes fluralaner (Bravecto, MSD Animal Health), sarolaner (Simparica, Zoetis LLC), afoxolaner (Frontline NexGard, as part of the complex drug NexGard Spectra, Boehringer Ingelheim LLC) (RU 2791637, RU 2772279, US 2015/0057239, WO 2023198476) [14-17] [5].

The closest analogue of the claimed invention is known from the source RU 2646 483 [11]. This patent describes solid pharmaceutical compositions based on isoxazoline compounds for oral administration, among which 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4 H -1,2-oxazol-3-yl]-2-methyl- N -[2-oxo-2-(2,2,2 trifluoroethylamino)ethyl] benzamide (fluralaner) is declared as the active substance and excipients are provided, including: polyethylene glycols, starch, soybean oil, glycerin, aspartame, magnesium stearate, sodium lauryl sulfate, flavoring, etc., which are part of the drug Bravecto. At the moment, the palatability of this drug is one of the best on the market, but it is still not satisfactory enough. Thus, the market for antiparasitic drugs for animals still needs to be expanded, and new drugs need to be developed that are palatable to pets, particularly dogs, to satisfy owners' demands for ease of administration of the drug into the animal's body while maintaining a pharmaceutically effective content of the active ingredient.

There is no domestically produced fluralaner-based drug on the domestic market. Therefore, the issue of import substitution is acute.

The objective of this invention is to create an antiparasitic agent based on isoxazoline - fluralaner in the form of a chewable tablet with an attractive taste and rapid release of the active substance, convenient, safe and non-toxic, with a high rate of insectoacaricidal action for the treatment and prevention of ectoparasitosis in dogs and high persistence of action.

This problem is solved by creating a special composition of the active ingredient and excipients. The excipients include a flavoring agent—dried beef liver. Therefore, the product contains a minimal amount of artificial additives and no natural-identical flavors. This composition imparts an attractive taste and aroma to animals, clearly resembling the treats they receive as a reward. Microcrystalline cellulose is used as a disintegrant at a concentration of 5% by weight. The tablets according to the invention disintegrate rapidly, allowing the active ingredient to have maximum contact with the dissolution medium for a short time.

This effect can be quantitatively assessed using the “Dissolution” test provided for by the State Pharmacopoeia of the Russian Federation for the tablet dosage form [3].

The technical result of the invention consists in obtaining a safe domestic medicinal product in the form of a chewable tablet with an attractive taste, providing a high rate of insectoacaricidal action, a long-term preventive effect against ectoparasitoses using available auxiliary components and a method that is simple in terms of equipment design.

The proposed medicinal product contains: fluralaner 8-24%, preferably 14-18%, dried beef liver 50-60%, microcrystalline cellulose 4-10%, aspartame less than 0.4%, macrogol 3350 6-10%, polyethyleneglycol 400 2-3% and glycerin up to 100%.

This composition is unique and unexpected for a specialist, the effect of the above combination of components was that the content of microcrystalline cellulose (MCC) can be reduced from 25% to 4-10%. The possibility of using such low quantities of MCC in the production of tablets with a rapid disintegration effect is absolutely unexpected for a specialist, since it is known from the prior art that the efficiency of the disintegrating action of MCC is low, and it is required up to 20% [14]. The specified combination of components also made it possible to reduce the content of aspartame from 0.5% to less than 0.4% and even to 0.3%. Moreover, it is known that aspartame is an artificial sweetener that has been widely used since the 1980s in the composition of various food products and beverages, as well as in the composition of toothpaste and medicines. Assessments of aspartame do not provide any serious grounds for doubting its safety at the doses it is typically consumed in. However, they do indicate potential effects that require further, more thorough research [15]. Therefore, the ability to reduce the amount of aspartame in the drug without compromising its palatability is an absolute success of the developed product. It was also possible to reduce the macrogol content from almost 16% to 6-10% without losing its potency.

The choice of the active substance is determined by the mechanism of action and pharmacokinetic characteristics in the animal body. The mechanism of action of fluralaner is based on the blockade of ligand-gated chloride channels: GABA and glutamate receptors, leading to paralysis and death of insects and ticks. Fluralaner has high selectivity for arthropod neurons compared to mammalian neurons [6]. It is effective against ixodid ticks ( Ixodesricinus , Ixodesscapularis , Ixodushexagonus , Dermacentorreticulatus , Rhipicephalus sanguineus, etc.), mites Demodex spp., Otodectes spp., Sarcoptes spp. and fleas ( Ctenocephalidesfelis and C. canis ) [10]. It has high lipid solubility and is easily absorbed. It is characterized by a high degree of binding to plasma proteins (≤99.9%), a relatively high volume of distribution and a low clearance value, which ensures effective concentrations of the substance for 12 weeks after a single application of the drug [7].

The claimed invention is implemented as follows.

Samples of dried beef liver, aspartame, and fluralaner are added to a mixing device and held until the components are completely uniformly distributed. Samples of macrogol 3350 and polyethyleneglycol 400 are placed in a separate container and heated to 70°C in a water bath with occasional stirring until the macrogol is completely melted. The melt is slowly added to the mixing device until the polyethyleneglycols are completely distributed throughout the mixture. The resulting mixture is cooled to 4°C. After cooling, a sample of glycerin is added and mixed until it is completely distributed throughout the mixture. Lastly, a sample of microcrystalline cellulose is added and mixed until a homogeneous mixture is obtained, preventing heating and sticking of the semi-finished product. After confirming the quality and homogeneity of the mixture, it is transferred to tableting. All active ingredients and excipients are used at the above-mentioned concentrations.

The drug Bravecto in tablet form with the active ingredient fluralaner can be used as one of the analogues of the claimed antiparasitic drug.

Examples of specific performance.

For specific implementation, the following compositions were used:

Sample No. 1: fluralaner 16.07%, dried beef liver 58.22%, microcrystalline cellulose 5%, aspartame 0.3%, macrogol 3350 8.3%, polyethyleneglycol 400 2.1% and glycerol up to 100%;

Sample No. 2: fluralaner 15.3%, dried beef liver 60%, microcrystalline cellulose 4%, aspartame 0.1%, macrogol 3350 9%, polyethyleneglycol 400 2.0% and glycerol up to 100%;

Sample No. 3: fluralaner 14.0%, dried beef liver 55.1%, microcrystalline cellulose 8%, aspartame 0.35%, macrogol 3350 6%, polyethyleneglycol 400 3% and glycerol up to 100%;

Sample No. 4: fluralaner 18.01%, dried beef liver 59.7%, microcrystalline cellulose 10%, aspartame 0.39%, macrogol 3350 10%, polyethyleneglycol 400 2% and glycerol up to 100%;

Sample No. 5: fluralaner 15.9%, dried beef liver 55.02%, microcrystalline cellulose 5%, aspartame 0.3%, macrogol 3350 8.5%, polyethyleneglycol 400 2.2% and glycerol up to 100%;

Sample No. 6: fluralaner 16.0%, dried beef liver 58.25%, microcrystalline cellulose 5.1%, aspartame 0.31%, macrogol 3350 8.2%, polyethyleneglycol 400 2.15% and glycerol to 100%.

For Bravecto, 6 tablets were randomly selected from packages purchased from different batches.

Example 1. Evaluation of the release of fluralaner from chewable tablets of the claimed medicinal product and Bravecto in the Dissolution Test

The dissolution test is one of the main analytical tests for all solid dosage forms for internal use. In accordance with the requirements of the General Pharmacopoeia article 1.4.2.0014.15 "Dissolution for solid dosage forms", an analysis of chewable tablet samples of the claimed medicinal product and Bravecto was carried out. Dissolution medium: aqueous solution with the addition of sodium dodecyl sulfate, dissolution medium volume - 900 ml; test temperature - 37°C; paddle stirrer rotation speed - 100 rpm; test time - 45 min. To determine the degree of fluralaner release, high-performance liquid chromatography with ultraviolet detection was used, detector wavelength: 265 nm, mobile phase flow rate: 1.0 ml/min, column: C18, 4.6×250 mm, sorbent diameter - 5 μm, thermostat temperature: 40.0°C, eluent: acetonitrile/60 mm aqueous solution of orthophosphoric acid in a ratio of 80/20; elution mode: isocratic.

Table 1. Results of the “Dissolution” test for the claimed medicinal product and the drug Bravecto in the form of chewable tablets weighing 700 mg

The claimed medicinal product Bravecto No. Average fluralaner content in tablets, mg Amount of fluralaner released into solution Acceptance criterion, Q+5% at Q=75.0% No. Average fluralaner content per tablet, mg Amount of fluralaner released into solution Acceptance criterion, Q+5% at Q=75.0% mg % mg % 1 112.5 100.3 89.16 > 80.0 1 112.5 83.4 74.13 <80.0 2 98.1 87.20 2 79.1 70.31 3 97.4 86.58 3 81.8 72.71 4 96.9 86.13 4 82.6 73.42 5 98.0 87.11 5 82.9 73.69 6 96.8 86.04 6 81.7 72.95

All studied samples of the proposed medicinal product, under the selected conditions, met the requirements of the XIV State Pharmacopoeia: at least 86% of the active substance contained in the chewable tablet was released into the dissolution medium. On average, 72.86% of the active substance was released into the dissolution medium from Bravecto tablets containing 112.5 mg of fluralaner, which does not meet the requirements of the State Pharmacopoeia.

Example 2. Titration of a therapeutic dose and evaluation of the effectiveness and rate of therapeutic action of the claimed medicinal product for entomoses in dogs.

Studies to study the therapeutic efficacy of the claimed medicinal product for entomoses were conducted on spontaneously infected with parasites dogs of different breeds and mongrel dogs of different sexes, ages and body weights (puppies from 8 weeks to 6 years of age, with a body weight of 6 to 37 kg). A total of 68 dogs infected with entomoses were selected for the studies, including 48 dogs with Ctenocephalides canis and 20 dogs with Linognatus setotus . When titrating the therapeutic dose for ctenocephalidosis, the claimed medicinal product was used in doses of 10, 25 and 70 mg / kg by active ingredient (active ingredient); for linognatosis - at a dose of 25 mg / kg by active ingredient. The drug Bravecto for these diseases was administered at a dose of 25 mg / kg by active ingredient. The animals ingested the claimed medication and Bravecto chewable tablets; in other cases, they were fed with food or administered forcefully. Animals were treated with the medication once. Following administration, the animals were monitored daily, including their general condition, food and water intake, and behavior. The skin and fur were examined at 6, 8, 12, and 24 hours during the first 24 hours after administration, as well as at 21, 28, 56, and 84 days. Efficacy was assessed using a critical laboratory test, calculating the average number of parasites detected (Tables 2 and 3). Infected dogs were assessed for symptoms of allergic dermatitis (redness, papules, scaling, crusting, etc.) before administration of the medication and Bravecto, and the percentage reduction in these symptoms was calculated after treatment.

Table 2 - Efficacy of the claimed medicinal product and the drug Bravecto for entomosis in dogs during the first day after using the claimed medicinal product and the drug Bravecto

Infestation intensity (number of parasites, specimens/animal) / Efficiency Before the experience In 6 hours Efficiency, % In 8 hours Efficiency, % In 12 hours Efficiency, % In 24 hours Efficiency, % Dogs infected with Ctenocephalides canis are treated with the claimed product at a dose of 10 mg/kg 17.6±1.3 6.2±1.0 64.77 4.4±0.3 75.0 2.9±0.2 83.52 2.5±0.1 85.80 Dogs infected with C. canis are treated with the claimed product at a dose of 25 mg/kg 19.1±1.7 - 100 - 100 - 100 - 100 Dogs infected with C. canis are treated with the claimed product at a dose of 70 mg/kg 18.5±1.4 - 100 - 100 - 100 - 100 Dogs infected with C. canis treated with Bravecto 18.9±1.2 5.4±0.2 71.43 - 100 - 100 - 100 Dogs infected with Linognathus setosus, treatment with the claimed product 6.1±1.0 5.9±1.1 3.27 5.9±1.0 3.27 5.8±0.9 4.91 5.8±1.1 4.91 Dogs infected with L. setosus treated with Bravecto 7.0±1.2 6.9±1.2 1.43 6.8±1.3 2.86 6.8±1.2 2.86 6.7±1.1 4.29

Table 3 - Efficacy of the claimed drug and the drug Bravecto in entomosis of dogs in subsequent study periods

Infestation intensity (number of parasites, specimens/animal) Before the experience In 21 days Efficiency, % In 28 days Efficiency, % After 56 days Efficiency, % After 84 days Efficiency, % Dogs infected with Ctenocephalides canis are treated with the claimed product at a dose of 10 mg/kg 17.6±1.3 2.7±0.1 84.69 2.9±0.2 83.52 3.5±0.2 80.11 3.7±0.2 78.98 Dogs infected with C. canis are treated with the claimed product at a dose of 25 mg/kg 19.1±1.7 - 100 - 100 - 100 - 100 Dogs infected with C. canis are treated with the claimed product at a dose of 70 mg/kg 18.5±1.4 - 100 - 100 - 100 - 100 Dogs infected with C. canis treated with Bravecto 18.9±1.2 - 100 - 100 - 100 - 100 Dogs infected with Linognathus setosus, treatment with the claimed product 6.1±1.0 - 100 - 100 - 100 - 100 Dogs infected with L. setosus treated with Bravecto 7.0±1.2 1.1±0.0 84.29 - 100 - 100 - 100

Table 4 - Reduction of symptoms of allergic dermatitis in dogs affected by Ctenocephalides canis after the use of the claimed product and Bravecto at a dose of 25 mg/kg, %

Symptoms Reduction of dermatitis symptoms after using the drug, % Number of cured dogs from the total number in the group Reduction of dermatitis symptoms after using the claimed product, % Number of cured dogs from the total number in the group Erythema 83.33 10/12 100.0 12/12 Peeling 83.33 10/12 91.67 11/12 Alopecia 91.67 11/12 100.0 12/12 Papules 83.33 10/12 100.0 12/12 crusts 83.33 10/12 100.0 12/12 Excoriation 91.67 11/12 100.0 12/12

The results of testing the claimed medicinal product at doses of 25 and 70 mg/kg demonstrated 100% efficacy against canine ctenocephalidosis 6 hours after treatment, as well as 100% efficacy against linognathosis on the 21st day after administration of the claimed medicinal product, the duration of action of the medicinal product being 12 weeks. The claimed medicinal product at a dose of 10 mg/kg demonstrated insufficient insecticidal activity - at a level of 78.98-85.80% throughout the entire experiment. The drug Bravecto, in turn, caused the death of all fleas in dogs 8 hours after treatment, providing 100% efficacy on days 21, 28, 56, and 84. For linognathosis, the drug Bravecto demonstrated 100% efficacy on days 28, 56, and 84. When observing experimental animals after the administration of the claimed drug at a dose of 70 mg/kg, one-time vomiting and lethargy were observed in two dogs; after treatment with Bravecto, itching was recorded in one dog.

It was established that the dose of the claimed drug - 25 mg/kg did not cause side effects during the entire observation period and is the optimal therapeutic dose for the treatment of entomoses.

In dogs affected by ctenocephalidosis, positive dynamics in the course of allergic dermatitis were noted (Table 4). After administration of the claimed drug and Bravecto at a dose of 25 mg/kg, there were no new lesions of scratching, flaking, or redness. The overall condition of dogs with symptoms of allergic dermatitis improved by 83.33% to 100% after treatment with Bravecto and by 91.67% to 100% after administration of the claimed drug alone.

Example 3. Evaluation of the effectiveness and rate of therapeutic action of the claimed medicinal product in ixodidosis in dogs

The study was conducted on spontaneously tick-infested dogs of various breeds and mongrel species of varying sex, age, and body weight. Twenty-six dogs with attached ixodid ticks were recruited for the study. The proposed medication and Bravecto were administered orally at a single dose of 25 mg/kg. Following treatment with the medication and Bravecto, the animals were monitored daily, including their general condition, food and water intake, and behavior. The skin and fur were examined after 10, 12, 24, 36, and 48 hours, and on days 14, 28, 56, and 84. The efficacy of the treatment was assessed using a laboratory diagnostic test, calculating the average number of parasites detected (Table 5).

Table 5 - Efficacy of the claimed drug and the drug Bravecto in ixodidosis in dogs

The claimed medicinal product The drug Bravecto Indicators Number of infected dogs, head Average number of ectoparasites before and after treatment, specimens/head Number of infected dogs, head Average number of ectoparasites before and after treatment, specimens/head Before the experience 13 6.1±0.3 13 6.9±0.2 In 10 hours 0 0 1 1.4±0.1 Efficiency, % 100 - - 79.71 In 12 hours 0 0 0 0 Efficiency, % 100 - 100 - In 24 hours 0 0 0 0 Efficiency, % 100 - 100 - In 36 hours 0 0 0 0 Efficiency, % 100 - 100 - In 48 hours 0 0 0 0 Efficiency, % 100 - 100 - In 14 days 0 0 0 0 Efficiency, % 100 - 100 - In 28 days 0 0 0 0 Efficiency, % 100 - 100 - After 56 days 0 0 0 0 Efficiency, % 100 - 100 - After 84 days 0 0 0 0 Efficiency, % 100 - 100 -

Ten hours after administration of the claimed medicinal product, no ixodid ticks were detected during clinical examination of the animals. No re-infestation by ticks was observed for 84 days. Bravecto caused complete tick death within 12 hours and maintained its acaricidal activity for 84 days. No adverse events or complications were observed with the use of the claimed medicinal product or Bravecto.

Example 4. Evaluation of the effectiveness of the claimed drug for acarosis in dogs

The study was conducted on spontaneously infested mite-infested dogs of various breeds and mongrel species of different sexes, ages, and body weights. The animals were divided into equal groups based on the pair-analog principle. A total of 21 dogs infested with Sarcoptescanis , 24 dogs infested with Otodectescynotis , and 20 dogs infested with Demodexcanis were selected for the study. The claimed medicinal product and Bravecto were administered orally at a single dose of 25 mg/kg. After treatment with the medicinal product and the preparation, the animals were observed daily: their general condition, food and water intake, and behavior were taken into account. The skin and fur were examined after 14, 28, 56, and 84 days, and the efficacy was recorded using laboratory diagnostics using the "critical test" type, with the average number of detected parasites calculated (Table 6).

Table 6 - Efficacy of the claimed drug and the drug Bravecto for acarosis in dogs

The claimed medicinal product The drug Bravecto Indicators Number of infected dogs, head Average number of ectoparasites before and after treatment, specimens/head Number of infected dogs, head Average number of ectoparasites before and after treatment, specimens/head Sarcoptescanis Before the experience 10 8.2±0.3 11 7.9±0.2 In 14 days 4 2.6±0.1 6 3.3±0.1 Efficiency, % 68.29 - 58.22 - In 28 days 0 0 1 0.2±0.1 Efficiency, % 100 - 97.47 - After 56 days 0 0 0 0 Efficiency, % 100 - 100 - After 84 days 0 0 0 0 Efficiency, % 100 - 100 - Otodectescynotis Before the experience 12 13.7±1.2 12 12.9±1.5 In 14 days 5 5.4 ±0.6 6 6.1±0.7 Efficiency, % 60.58 - 52.71 - In 28 days 0 0 1 0.2±0.1 Efficiency, % 100 - 98.44 - After 56 days 0 0 0 0 Efficiency, % 100 - 100 - After 84 days 0 0 0 0 Efficiency, % 100 - 100 - Demodexcanis Before the experience 10 9.1±0.9 10 9.3±0.8 In 14 days 5 3.6±0.5 5 4.0±0.4 Efficiency, % 60.43 - 56.99 - In 28 days 0 0 1 0.7±0.2 Efficiency, % 100 - 92.47 - After 56 days 0 0 0 0 Efficiency, % 100 - 100 - After 84 days 0 0 0 0 Efficiency, % 100 - 100 -

Twenty-eight days after treatment with the claimed agent, dead ticks, deformed larvae, and eggs were detected in scrapings of animals infected with S. canis , O. cynotis , and D. canis . Further observation of the experimental animals for 84 days revealed that all treated animals were free of ticks. A similar recovery rate was observed after administration of Bravecto. However, on the 28th day of the experiment, a D. canis tick was detected in skin scrapings of one dog (92.47%), while isolated O. cynotis (98.44%) and S. canis (97.47%) ticks were observed. No side effects or complications were observed during the administration of the test agents.

Example 5. Evaluation of the prophylactic efficacy of the claimed medicinal product for ectoparasitosis in dogs

A study of prophylactic efficacy was conducted on 48 clinically healthy dogs of various breeds that had not been treated with insectoacaricidal preparations for at least 30 days. No ectoparasites were detected on the skin or fur surface of the animals during a clinical examination. The animals were divided into 8 experimental groups of 6 dogs, each of which was infested with 50 female and 10 male Ixodes ricinus ticks. After two days, the dogs of four experimental groups were given a single oral dose of the claimed medicinal product at a dose of 25 mg/kg; dogs of the other groups did not receive treatment and served as controls. After 28, 56, and 84 days from treatment, all dogs were again infested with 50 female I. ricinus ticks, and an examination for the presence of live or dead ticks was performed 4, 8, 10, and 24 hours after each reinfestation. The drug's efficacy at each time point was calculated by comparing the experimental group with the corresponding control group. The claimed drug demonstrated 86.4% activity at 4 hours, 97.5% at 8 hours, and 100% at 10 and 24 hours after application. Ten hours after reinfestation, efficacy was 99.9%, 99.6%, and 95.4% at 28, 56, and 84 days post-treatment, respectively. Thus, throughout the entire 12-week period of effectiveness, the claimed drug ensures complete eradication of ticks within 10 hours of infestation, which helps, among other things, prevent tick-borne diseases.

Example 6. Evaluation of the palatability of chewable tablets of the claimed medicinal product and the drug Bravecto

The taste appeal of chewable tablets was assessed during the study of the therapeutic and prophylactic efficacy of the claimed product and the drug Bravecto against ectoparasitosis on 208 dogs (Table 7).

Table 7. Eatingability of chewable tablets of the claimed medicinal product and the drug Bravecto

Tablet edibility Number of dogs treated, % Bravecto (n=68) The claimed remedy
(n=139) Voluntarily within 1 minute 71 83 Voluntarily within 1-5 minutes 6.4 3.6 Introduction with food/treat 11.4 8.5 Forced introduction 10.7 4.9 Introduction by a veterinarian 0.5 0.0

It was found that 77.4% of dogs voluntarily consumed Bravecto chewable tablets within 5 minutes of being offered, 11.4% of dogs ate the tablets with food or a treat, and 11.2% of dogs were forced to take Bravecto. Chewable tablets of the claimed medication were more readily accepted by dogs within 5 minutes of being offered (86.6%), with only 4.9% of all animals receiving the drug forcibly.

Example 7. Study of acute toxicity parameters of the claimed medicinal product on white mice

A key parameter for developing and implementing medicinal products is determining their toxicity. Therefore, we conducted a toxicological screening of the proposed medicinal product, proposed in this application. The studies were conducted in accordance with the Methodological Recommendations of the State Pharmacological Committee and the guidelines for preclinical trials of medicinal products. Acute oral toxicity was studied using white, outbred male mice weighing 18-22 g. Two groups of 10 animals each were formed, each receiving a single intragastrically administered dose of the proposed medicinal product at the maximum recommended doses: 10,000 and 5,000 mg/kg. The animals' general condition and behavior, potential mortality, intoxication symptoms, and food and water intake were monitored for 14 days. At the end of the observation period, the experimental animals were decapitated and subjected to a postmortem examination.

The claimed product, at all doses tested, did not cause any symptoms of intoxication or death in animals throughout the entire observation period. The mice were active, readily consumed food and water, responded to external stimuli, and exhibited normal general condition and behavior. Table 8 presents the results of intragastric administration to mice.

Table 8 - Results of intragastric administration of the claimed medicinal product to mice

Dose,
mg/kg Total number of mice survived fell 10000 10 0 5000 10 0

Since the 10,000 mg/kg dose was the maximum possible for intragastric administration to laboratory animals and there were no signs of intoxication, the maximum oral dose was tentatively taken as the _LD50 . Taking into account the established _LD50 values, according to the generally accepted hygienic classification GOST 12.1.007-76, the claimed product belongs to hazard class IV—low-hazard substances.

Example 8. Study of acute toxicity parameters of the claimed medicinal product on white rats

To study acute oral toxicity, a group of animals was formed consisting of six albino male rats weighing 170-190 g. The claimed product was administered to the rats once via a gastric tube at the maximum administered dose of 12,000 mg/kg. Clinical observation of the animals revealed that no symptoms of intoxication were observed after oral administration. The animals were active, readily consumed food and water, and their general condition and behavior were within physiological norms. Due to the low toxicity of the drug, the maximum oral dose of 12,000 mg/kg was conventionally taken as the LD _50. According to the generally accepted hygienic classification GOST 12.1.007-76, the claimed medicinal product belongs to hazard class 4 (low-hazard substances).

Based on the results of the research, the following conclusions were made.

The use of the proposed drug provides high therapeutic and prophylactic efficacy in ectoparasitosis of dogs for 84 days after a single administration.

Compared to Bravecto, this product is more palatable to dogs, exhibits rapid insecticidal acaricidal action, effectively reduces the symptoms of allergic dermatitis, and causes no side effects. This is due to the optimal combination of fluralaner, flavoring, and excipients, which facilitate rapid release of the active ingredient and the onset of its pharmacological action.

The results of an acute oral toxicity study of the drug demonstrate its safety and classification as a low-hazard substance according to GOST 12.1.007-76. The invention is industrially applicable and cost-effective to manufacture and use. It is available for dogs in the form of chewable tablets with an appealing flavor, ensuring ease of use.

List of sources used and taken into account when preparing the application:

1. Gerunova L.K., Smyslova P.Yu. Skin-resorptive effect of fipronil- and permethrin-containing drugs // Veterinary doctor. - 2018. - No. 5. - P. 31-36.

2. Zakusimova K.S., Semenko A.V. Distribution and methods of control of ectoparasites of carnivorous animals // Scientific Bulletin. Series: Veterinary medicine, quality and safety of livestock products. 2018. No. 293. P. 167-174.

3. OFS 1.4.2.0014.15 "Dissolution for solid dosage forms". State Pharmacopoeia of the Russian Federation, XIV ed. Vol. 2. 2018.

4. Smyslova P.Yu. Modern range and mechanisms of action of insectoacaricides for small domestic animals // Current issues of veterinary biology. 2013. No. 3 (19). P. 61-67.

5. FDA (2014). Corrected Freedom of Information Summary, original new animal drug application NADA 141-426, Bravecto (fluralaner Chewable Tablets, dogs). https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/1502.Retrieved March 19, 2020.

6. Gassel M., Wolf C., Noack S., Williams H., Ilg T. The novel isoxazoline ectoparasiticide fluralaner: selective inhibition of arthropod γ-aminobutyric acid- and L-glutamate-gated chloride channels and insecticidal/acaricidal activity. Insect Biochem. Mol. Biol. 2014, 45:111-124.

7. Kilp S., Ramirez D., Allan M. J., Roepke, R. K. A. Comparative pharmacokinetics of fluralaner in dogs and cats following single topical or intravenous administration. Parasites & Vectors. 2016. 9(1), 296.

8. Mealey K.L. Therapeutic implications of the MDR-1 gene. J. Vet. Pharmacol. Ther. 2004. 5:257-64.

9. Riviere J. E., Papich M. G. Veterinary Pharmacology and Therapeutics. Wiley_Blackwell, 2009. - 1544 r.

10. Rohdich N., Roepke R.K.A., Zschiesche E. A randomized, blinded, controlled and multi-centered field study comparing the efficacy and safety of Bravecto™ (fluralaner) against Frontline™ (fipronil) in flea_and tick-infested dogs. Parasit. Vectors. 2014, 7:83.

11. RU 2646483 “Solid pharmaceutical compositions for oral administration based on isoxaline compounds ” dated 05.03.2018.

12. RU 2657508 “Combined antiparasitic agent for the treatment and prevention of helminthiasis and arachnoentomoses of carnivorous animals” dated 14.06.2018

13. RU 2782929 "Complex antiparasitic agent for animal protection" dated 11.07.2022.

14. I.E. Smekhova, V.A. Weinstein, Yu.M. Ladutko, O.V. Druzhininskaya, N.N. Turetskova, Disintegrants and their influence on the dissolution of substances of different classes according to the biopharmaceutical classification system, Development and registration of drugs, 2018, No. 4 (25), pp. 62-72.

15. Aspartame Hazard and Risk Assessment Results Released, WHO website, published 14.07.2023 https://www.who.int/ru/news/item/14-07-2023-aspartame-hazard-and-risk-assessment-results-released

16. RU 2791637 "Isoxazoline compositions and their use in the prevention or treatment of parasitic infestations of animals" dated 03/13/2023

17. RU 2772279 "Solid pharmaceutical compositions for oral administration based on isoxazoline compounds" dated 18.05.2022

18. US 2015/0057239 “Solid oral pharmaceutical compositions for isoxazoline compounds” 02/26/2015

19. WO 2023198476 “Soft chewable veterinary dosage form” 10/19/2023.

Claims (8)

1. An insectoacaricidal agent intended for oral use in the form of a chewable tablet, containing an active ingredient, a flavoring agent and auxiliary substances with the following component content, wt.%: fluralaner 14-18 dried beef liver 50-60 microcrystalline cellulose 4-10 aspartame 0.1-0.39 macrogol 3350 6-10 polyethylene glycol 400 1-4 glycerol up to 100 2. An insectoacaricidal agent according to claim 1, wherein the tablets contain an active substance, a flavoring agent and auxiliary substances with the following component content, wt.%: fluralaner 16.07 dried beef liver 58.22 microcrystalline cellulose 5 aspartame 0.3 macrogoal 3350 8.3 polyethylene glycol 400 2.1 glycerol up to 100 3. An insectoacaricidal agent according to paragraph 1, where the agent is intended for use in dogs. 4. An insectoacaricidal agent according to claim 1, where the agent is intended for oral administration at a dose of 25 mg/kg. 5. An insectoacaricidal agent according to claim 1, wherein the agent is intended for the prevention of canine entomosis, in particular ctenocephalidosis or linognathosis; canine ectoparasitosis, in particular canine ixodidosis; canine acarosis, in particular the prevention of infection with S. canis , O. cynotis and D. canis. 6. An insectoacaricidal agent according to claim 1, where the agent is intended for single oral use.