CHITOSAN MICROSPHERES OF NIFEDIPINE AND NIFEDIPINE-CYCLODEXTRIN INCLUSION COMPLEXES

Chitosan microspheres of nifedipine and nifedipine-cyclodextrin comple xes were prepared by the glutaraldehyde cross-linking of chitosan. Mic rospheres having different degrees of swelling were made by varying th e cross-linking density. Drug incorporation efficiencies exceeding 70% could be achieved for this drug. In vitro release rates were influenc ed by the cross-linking density, particle size and initial drug loadin g in the microspheres. While the solubility of nifedipine was enhanced by inclusion into a cyclodextrin complex, the drug release from the c omplex was significantly reduced. In addition the drug release mechani sms were discussed.