Background. Due to the high prevalence of chronic venous insufficiency among the population, with a decrease in the quality of life of patients and their early disability, there is a need to develop modern effective and safe means for the prevention and treatment of this pathology. We have developed the optimal composition and technology of a gel for external use based on a nanobiocomposite of dihydroquercetin and arabinogalactan, which has a venoprotective effect. The article presents data on the results of a preclinical study of the safety and specific activity of the gel.The aim. To study the specific activity (decongestant, antitranssudative action) and safety of a gel for external use based on nanobiocomposite of dihydroquercetin and arabinogalactan used for the treatment of chronic venous insufficiency in the framework of preclinical studies.Materials and methods. The object of the study was a gel for external use based on dihydroquercetin and arabinogalactan nanobiocomposite. The study was conducted on 32 white male rats of the same age, for 15 days. The study of the pharmacological activity of a gel based on a nanobiocomposite of dihydroquercetin and arabinogalactan, was carried out on a model of acute venous stagnation in the tail of a rat (edema of non-inflammatory genesis), the dynamics of tail volume growth in the experimental and control group of animals was evaluated. The irritant effect of the gel on the skin of animals was also determined, the permeability of the capillaries of the skin was determined.Results. When studying the pharmacological activity of the gel on a model of acute venous stagnation in the tail, it was shown that a soft dosage form for external use developed on the basis of nanobiocomposite of dihydroquercetin and arabinogalactan has decongestant and antitranssudative activity. The presence of a locally irritating effect in the gel under study has not been established in the framework of the experiment.Conclusion. In the course of preclinical study of the gel of the nanobiocomposite dihydroquercetin and arabinogalactan on laboratory animals, its antitranssudative activity and safety have been proven.