[In-vitro degradation of the chitosan membranes under various syntheses conditions].

The hydrolytic degradation of polymer films, which were obtained by application of 2% and 3% chitosan solutions in 1% acetic acid on a base sheet has been investigated. As the solvent was removed, these firms were either treated with 0.5% NaOH for 3 min or with phosphate buffer (рН 8) for 10 min. The degrees of degradation for the obtained samples were studied during 1-96 h in solutions with pH values of 5.0, 7.0 and 8.5. The results revealed resistance of the films within the first 6 h, followed by their subsequent degradation. The rate of degradation depended on pH of the solution, chitosan percentage and the treatment methods of films. The materials with the initial chitosan content of 3% were more resistant to the hydrolytic degradation, but the decreasing in pH accelerated the weight loss of the film. However, if the membranes were treated with phosphate buffer, the rate and degree of sample degradation were slowed down. Thus, the results are considered as a basis for the further development of biomaterials to treat the skin surface damages.