Composite PHB/Chitosan Microparticles Obtained by Spray Drying: Effect of Chitosan Concentration and Crosslinking Agents on Drug Relesase

The purpose of this study was to prepare composite microparticles of poly(3-hydroxybutyrate) (PHB) containing the drug ketoprofen (KET) coated with a layer of crosslinked chitosan (CHI) for application as a controlled drug-release system. Microparticles of PHB containing KET as a model drug were prepared using the emulsion-solvent evaporation technique, and coated with a film of chitosan by spray drying to obtain the composite microparticles. The surface film was modified using glutaraldehyde or genipin as the crosslinking agent. The KET encapsulation efficiency of the PHB microparticle was 60%, and the same value was obtained after inclusion of the CHI film by the spray drying process. The influence of the concentration of chitosan used to obtain the composite microparticles and the crosslinking agent on the amount of drug released after 1 and 72 h was evaluated by statistical analysis, and both variables were found to affect the responses. The drug release from the composite microparticles coated with crosslinked chitosan was slow and sustainable, indicating that this represents a very promising polymeric carrier for drug delivery.