DRUG SYNTHESIS METHODS AND PRODUCTION TECHNOLOGY POLY(3-HYDROXYBUTYRATE)-CHITOSAN: A NEW BIODEGRADABLE COMPOSITION FOR PROLONGED DELIVERY OF BIOLOGICALLY ACTIVE SUBSTANCES

摘要

A new polymer composition based on bacterial poly-3-hydroxybutyrate and chitosan encapsulating the wide-spectrum antibiotic rifampicin was developed. Both biopolymers are biocompatible and can undergo enzymatic and hydrolytic degradation. Variations in the ratio of poly-3-hydroxybutyrate and chitosan in the mixture, altering the ratio of hydrophilic and hydrophobic components, influenced not only the sorption capacities for water and drug but also the controlled release profile of the drug. Analysis of kinetic curves for rifampicin release showed that drug release was determined by the superimposition of two processes: drug desorption by a diffusional mechanism and hydrolytic degradation of poly-3-hydroxybutyrate, which was most marked after the initial diffusional stage. Kinetic parameters (the constant of hydrolysis of poly-3-hydroxybutyrate k and the coefficient of diffusion of rifampicin D) were required for a full description of the poly-3-hydroxybutyrate-chitosan-rifampicin system. The fact that the kinetic curves had a prolonged linear region suggests that this composition may have value as a biodegradable therapeutic system for local controlled drug release.