PREPARATION AND IN-VITRO EVALUATION OF NIFEDIPINE LOADED ALBUMIN MICROSPHERES CROSS-LINKED BY DIFFERENT GLUTARALDEHYDE CONCENTRATIONS

Nifedipine-loaded albumin microspheres were prepared by a chemical cro ss-linking method to develop a sustained release form. The effects of cross-linking agent (glutaraldehyde) on the percentage of drug loading , biodegradability of albumin microspheres and drug release kinetics w ere investigated in this study. Moreover, the kinetics of nifedipine r eleased from different albumin microspheres were analysed using four d ifferent theoretical models, that is, zero order, first order, planar matrix and spherical matrix model. Albumin microspheres prepared with different amounts of glutaraldehyde indicated different release kineti cs. Increasing the glutaraldehyde concentration decreased the release rate of nifedipine from albumin microspheres as a result of formation of greater structural strength and more tightly texture. Besides, albu min microspheres gave an adequate fit to either zero order or spherica l matrix model, depending on the extent of cross-linking reaction. Cop yright (C) 1996 Elsevier Science B.V.