Analysis of model drug release kinetics from complex matrices of polylactide-chitosan

In the present paper the Authors analyse the experimental results of a model drug (ibuprofen) release approximated with three commonly used semi-empirical models: Korsmeyer-Peppas, first order kinetics and Gallagher-Corrigan equation. Drug carriers in the form of films composed of chitosan matrix and polylactide microparticles were produced by ultrasonic emulsification with solvent evaporation followed by film casting technique. Additionally, polylactide shield layers (5μm thick) were attached to both sides of obtained films by means of spray-coating process. A microscopic analysis confirmed the uniform distribution of polylactide microparticles (diameter: 1-2 μm) within chitosan films. Based on the of microscopic study, molecular drug dispersion within composite matrices was found. Fraction of ibuprofen released into medium of pH equal to 1.4 or 7.2 (GI tract) was measured by means of UV-VIS spectrophotometry. The finest approximation was obtained by fitting two-stage release model derived by K. M. Gallagher and O. I. Corrigan to the release data. Analysis of model parameters led to the conclusion that the increase of composite films thickness as well as weight fraction of PLA microparticles within films prolong drug release