Kinetics of the release of a drug from a soluble or hydrolyzable polymer matrix

Film systems based on chitosan with different molecular weights (334 000 and 113000 Da) and amikacin, an aminoglycoside series antibiotic, are studied. The Ritger–Peppas, Hixson–Crowell, and Hopfenberg equations for describing the kinetics of drug release are tested. It is demonstrated that the release of amikacin from chitosan acetate films under conditions of concurrent diffusion and dissolution (hydrolysis) of the polymer matrix are more closely described by the Hopfenberg equation. It has been established that the isothermal annealing of the film causes a decrease in the kinetic constants characterizing the rate of drug release from the polymer matrix.