[Effect of physicochemical parameters on the formation of chitosan-based gels]

The possibility for forming physical gels based on Pchelozan (bee chitosan with a molecular weight of 230 kDa and an acetylation degree of 26-65%) has been demonstrated. Conditions for obtaining the gels (1% solution in 1% glycolic acid, 25 degrees C, pH 5.5-7.5) were selected. The effects of (1) the concentration of the original solution, (2) the degree of acetylation of Pchelozan, and (3) the value of pH on the process of gel formation, were studied. The gels obtained may be classified with reversible toxotropic systems. These gels are stable for a long time when stored within a temperature range of 18-55 degrees C. The gel with a degree of acetylation of 34% was characterized by irreversible syneresis.