Introduction. The spread of antibiotic- and antiseptic-resistant hospital-acquired infections is a highly relevant problem both in Ukraine and in other countries, even those with developed and modern healthcare systems. For example, cases of the spread of nosocomial strains in the United States , the European Union , Canada, the United Kingdom, Japan, etc. have been described. The World Health Organization describes the problem of the spread of nosocomial strains as global and one that needs to be addressed as soon as possible. In Ukraine, additional negative factors contributing to the spread of nosocomial infections include - a significant increase in the burden on health care facilities, especially military ones, due to a significant number of patients with gunshot wounds and mine-blast injuries sustained as a result of the armed aggression of the rf . Gunshot wounds and mine-blast traumas are considered infected by default; - shortage of medical personnel in healthcare facilities in Ukraine; - widespread self-medication among the population, including with antibiotics, which results in pathogens gaining resistance to a wide range of antibiotic drugs. Materials and methods. Method of antiseptic treatment of infected Petri dishes. An 18-24 hour culture of microorganisms was used. Muller-Hinton agar was used for bacteria. Sabouraud agar was used for Candida albicans. The bacterial suspension was applied to a sterile Petri dish, the suspension was evenly distributed over the surface, and the Petri dish was placed in a sterile microbiological box for 20-25 minutes until the suspension was completely dry. After the suspension was completely dry, the infected surface of the Petri dish was treated with the IOON MED device. To establish the safety of the antiseptic synthesized by the IOON MED device, as well as to determine its effectiveness in vivo, a study was conducted on white laboratory mice. For the study, 30 healthy, young, linear white mice of both sexes were selected. The animals were divided into 3 groups of 10 animals each, each group was isolated in a cage, separately from the main population and other groups. The study was conducted to model purulent peritonitis in experimental animals according to FDA recommendations. Animals in experimental group were injected with a lethal (LD100) dose of Pseudomonas aeruginosa intraperitoneally and 4 hours after the administration of the bacterial suspension, 1 ml of freshly synthesized IOON MED antiseptic at the maximum titer was injected and the animals were monitored for 24 hours, after which mortality in the group was recorded. Results and discussion. In fact, the antiseptic generated by the IOON MED device exhibits properties similar to the control products on the market. All antiseptic solutions generated by devices 1-5 showed antimicrobial activity against S. aureus - no staphylococcal growth was observed on the Petri dishes, while the control showed classic bacterial growth. On Petri dishes treated with test solutions from the IOON MED device (1-5), the growth of single colonies is observed, just as in the control groups, where Petri dishes with microorganisms were treated with hydrogen peroxide and chlorhexidine. The control hydrogen peroxide did not actually affect the biofilm and did not differ from the control, while chlorhexidine, similarly to the IOON MED solution samples, caused the death of all microorganisms in the biofilms. Thus, test groups 1-5 are statistically significantly different from the control group in terms of the degree of antimicrobial effect, while no statistical differences were observed from the effect of chlorhexidine. For samples 2, 3, 5, the titer of antimicrobial action was 1:64. For sample 4, the titer was 1:128. Thus, it can be reliably stated that the average titer of activity of the antiseptic solution generated by IOON MED based on the results of a twofold dilution of the solution is at least 1:64. In the group of mice that were injected with 1 ml of IOON MED antiseptic solution 3 hours after infection, 6 animals died, while in the control group of untreated mice all 10 animals died. The difference in the groups is statistically significant. Conclusion. The solution generated by the electrochemical device IOON MED is able to kill bacteria inside the biofilm formed on a fragment of the endotracheal tube by the multidrug-resistant strain Acinetobacter baumannii 718. Of the controls, only chlorhexidine showed antiseptic properties against bacteria inside biofilms. There is no statistical difference between the effectiveness of chlorhexidine and the test solutions 1-5. For the solutions generated by the electrochemical device IOON MED, titers were established - the maximum twofold dilutions that showed antiseptic properties. The average titer was 1:64, for individual samples 1:128 for multidrug-resistant S. aureus. The antiseptic solution generated by the IOON MED device showed statistically significant therapeutic antimicrobial activity in a model of purulent peritonitis in mice. Keywords. Antiseptic, electrochemical, antimicrobial, titer, peritonitis model in mice, atomic hydrogen, active chlorine