SCIENCE-BASED APPROACH TO THE EXPERIMENTAL DEVELOPMENT OF A BIODEGRADABLE CHITOSAN BASED CARRIER.

The aim of the study was to develop a science-based approach to the development of a carrier of a pharmaceutical substance using the modification of chitosan. Studies were carried out to determine the upper limit of acidity - ascorbic and acetic to obtain salt forms of chitosan, the choice of modification of chitosan and the experimental development of a method for obtaining its solid salt form. A scientifically based approach to research has made it possible to develop a technology for obtaining a water-soluble biodegradable carrier based on salt forms of chitosan. The experimental approach to research made it possible to establish the upper limit of the acidity of the medium, at which transparent solutions of chitosan were obtained, for acetic and ascorbic acids, which are necessary for modifying the native form of chitosan and obtaining its salt forms. Taking into account the better organoleptic properties compared to chitosan acetate, as well as higher pH values, which are close to the pH of wound exudate, and higher viscosities of the obtained solutions of salt forms of chitosan, it was possible to select a water-soluble form - chitosan ascorbate for further development of the composition of the dosage form. The optimal mode of freeze-drying in laboratory conditions was established to obtain a solid form of chitosan ascorbate with the following parameters: freezing for 2-3 hours at a temperature of minus 80 °C; drying mode for 40 hours, pressure - 0.34 mbar; post-drying mode for 8 hours, pressure - 0.12 mbar; condenser temperature minus 80°C.