DETERMINING PARAMETERS OF THE AEROSOL "METRAZOL-BIO" ACUTE TOXICITY AND CUMULATIVE PROPERTIES
Introduction. The indispensable prerequisite of using a new intrauterine aerosol “Metrozol-bio”, which is designed for prevention and treatment of postnatal intrauterine infections of cows, mares, swine, sheep and goats, is conducting preliminary toxicological studies on laboratory animals. The goal of the work was to determine the parameters of acute toxicity and cumulative properties of aerosol “Metrazol-bio” on laboratory animals. Materials and methods. The study of acute toxicity of an intrauterine aerosol “Metrazol-bio” with the active substance Chlorhexidine bigluconate was performed on 50 mice, weighing 18-20 g, and 40 white nondescript rats, weighing 180-200 g, which were in vivarium conditions at 18-25° C and humidity of 50-60% in standard plastic cages on a standard diet. The trial medication was injected over the skin (cutaneus) and intragastric. Calculation of median lethal dose (LD<sub>50</sub>) and other indicators was determined by Litchfield and Wilcoxon method modified by Roth (1963) and the method described in the publication “Preclinical studies of veterinary medications” (2006). Results of research and discussion. Intrauterine aerosol “Metrazol-bio” at intragastric administration to mice was studied in the dose range from 2,500 to 10,000 mg/kg live weight. Laboratory rats were administered a preparation in the dose range from 3,400 to 10,500 mg/kg live weight. In 20-30 minutes after administration of toxic doses of the preparation depression of laboratory mice took place and after 24 hours the animals died. After the administration of toxic doses of the preparation, depression of laboratory rats occurred in 30-40 minutes and after 24 hours the animals died. According to the research of “Metrazol-bio” acute toxicity parameters, it was set the value of LD<sub>50</sub> at intragastric administration to white mice, which was 5283 (4593,9- 6075,5) mg/kg. LD<sub>50</sub> at intragastric administration to rats accounted for 6100 (4149.7-8967) mg/kg. This allows relating the aerosol “Metrazol-bio” to the fourth class of danger (according to GOST (National State Standard) 12.1.007-76). The specified cumulation factor after repeated oral administration to white mice amounted 7,4, allowing to carry the medication to preparation without cumulative effect (if Kcum> 1). Conclusions and prospects for further research. According to the research of “Metrazol-bio” acute toxicity parameters it was set the value of LD<sub>50</sub> at intragastric administration to whitemice amounts to 5283 mg/kg. The value of LD<sub>50</sub> at intragastric administration to rats amounts to 6100 mg/kg. This allows attributing aerosol “Metrazol-bio” to the fourth class of danger. The specified cumulation coefficient amounted to 7.4, which allows attributing medication to preparation without cumulative effect. Further studies will relate to the definition of chronic toxicity, embryotoxic and teratogenic properties of “Metrazol-bio”.