Aim. The research of antimicrobial and toxicological parameters of a promising pharmaceutical composition with indole-3-carbinol and meloxicam in the form of rectal suppositories. Materials and methods. The research of antimicrobial activity was carried out in vitro by diffusion in nutrient agar in the modification of "holes" on the reference strains of common pathogens Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Candida albicans. Adult rats were used for the study of acute toxicity. Suppository mass were administrated in the largest possible volume rectally or orally. The animals were periodically monitored according to the experimental plan – the assessment of physiological parameters before administration and after 6, 12, 18, 24 hours, at 3, 7 and 14 days. The animals were removed from experiment and necropsy provided after 1, 3, 7, and 14 days. Results. The sizes of zones of inhibition of the microorganisms growth were most significant (from 19.27±0.61 mm of E. coli to 40.80±0.42 mm of S. aureus) near sample of the combined composition suppository compared with other combination of active substances and excipients. During the observation of animals for 14 days and the study of internal organs after autopsy, deviations in physiological (weight, temperature, activity, respiratory rate) and macroscopic morphological indicators of animals from reference values were not detected. Conclusion. According to the results of microbiological studies, a moderate antimicrobial effect of suppositories of combined composition in relation to all the studied pathogens was revealed. The absence of manifestations of acute toxicity allows us to conclude that the pharmaceutical composition can be classified as practically non-toxic substances. The obtained results allow us to recommend a pharmaceutical composition with indole-3-carbinol and meloxicam on a polyethylene oxide basis in the form of suppositories for further preclinical studies of specific pharmacological effects as a prostate protective agent.