Investigation of the effects of newly developed drugs containing several compounds on laboratory animals is an important step in scientifically establishing their effective dosage and safety. The purpose of this study was to investigate the effect of the new drug "Imun-depo" on the development of laboratory animals (white mice), their haematological parameters, and the viability of Tetrahymena pyriformis ciliate cells. The study material was female white laboratory mice of improved convential type in the amount of 60 animal units (30 units each in the control and experimental groups). The drug was administered to white laboratory mice intragastrically at a dose of 1.0 ml/animal from 14 days of age for 60 days. A set of methods was used to assess the state of the internal environment in the vivarium, the quality of drinking water, the dynamics of body weight and internal organs, behavioural responses of mice, haematological indicators of their body, and the viability of Tetrahymena pyriformis ciliates. It was found that the indicators of the internal environment of the vivarium and drinking water were within the limits of regulatory requirements. It was found that the drug at a dose of 1.0 ml/animal had an effect on body weight gain, while the weight of the thymus, thyroid gland, kidneys, liver, and spleen did not change. It was proved that in the blood of white laboratory mice, the haemoglobin content, the number of red blood cells, and the haematocrit level increased (within the reference values). Moreover, the indicators of the leukocyte formula of the mice’s blood did not change. In the blood serum, there was an increase (within the reference values) in the content of globulins, total protein, alanine aminotransferase activity, and a decrease in total cholesterol. According to the effect of the “Imun-depo” preparation on the viability of Tetrahymena pyriformis ciliate cells, the absence of toxic effects was noted. Scientifically based results of the effect of the “Imun-depo” preparation on the body of white laboratory mice are necessary for further experimental studies with the use of the drug to productive animals as a feed additive to the main diet
white mice; keeping conditions; body weight dynamics; morphology and biochemistry of blood; Tetrahymena pyriformis ciliates; “Imun-depo” preparation