Preparation ,Characterization and Evaluation of controlled release microspheres Containing Amphotericin B


The purpose of this research work was to prepare , characterize and evaluate microspheres for controlled release delivery of Amphotericin B (AmB) , as a model drug, with two natural polymers like Bovine Serum Albumin (BSA) and gelatin by a solvent/ evaporation method, induced by addition of glutaraldehyde (GA) as a cross-linking agent. The microspheres were characterized by Fourier transform infrared spectroscopy FT-IR, differential scanning calorimetry (DSC), and photomicrographs microscopy. The effect of different process parameters, such as drug/polymer ratio and Bovine Serum Albumin (BSA) / gelatin ratio, on the morphology, size distribution, in vitro drug release and release kinetics of microspheres were studied. The microspheres had mean diameters between 16-60 μm. The results show that the drug release rate from smaller microspheres was faster than from larger microspheres. Also the increasing the drug content of microspheres from 5 mg to 15 mg led to significantly faster drug release from microspheres. The total amount of drug released from microspheres after 12h in phosphate buffer saline, pH 7.4 at 37°C were 72% - 98% . The coefficient of determination indicated that the release data was best fitted with zero order kinetics. Higuchi equation explains the diffusion controlled release mechanism. Finally , The results show that biological activities for the microspheres loaded with AmB exceed biological activities against three types of fungal isolates including Candida albicans, Trichophyton rubrum, and Aepergillus fumigates in comparison with activity of AmB alone.