Toxicological assessment is a mandatory research step in the development of new insecticidal drugs. At the All-Russian Research Institute of Veterinary Entomology and Arachnology, a prototype of the insecticidal bait Mukhnet IF was obtained with an active ingredient content of 0.06% ivermectin and 0.015% fipronil, which showed a highly effective effect against houseflies. This work presents the results of the study of acute oral toxicity of the above agent. For this, male white mice with a live weight of 16-26 g were selected. They were kept on a starvation diet for one day in individual houses with water. The drug was given in mg/kg body weight the next day. A total of 33 doses have been tested, ranging from 100 mg/kg to 40,000 mg/kg. The animals were observed for 14 days. According to the research results, it was revealed that at doses up to 20,000 mg/kg there were no signs of intoxication, but when tested at 25,000 mg/kg in some mice, these signs were noted, and at 30,000, 35,000 and 40,000 mg/kg deaths were recorded 20±10, 45±30 and 60±20%, respectively. It was not possible to test the drug over the last above dose due to incomplete eaten by mice. According to the degree of danger for warm-blooded animals, the drug belongs to the 4th class of low-hazard drugs (average lethal dose of 5000 mg/kg or more) in accordance with the classification of GOST 12.1.007-76. When analyzing the literature data on the toxicological characteristics of preparations containing ivermectin and chlorfenapyr, it was revealed that the insecticidal agent in its acute toxicity for warm-blooded animals is comparable to known analogues.
