Stavudine Loaded Microcapsules using various Cellulose Polymers: Preparation and In-Vitro Evaluation

Abstract

The objective of the present study was to prepare and characterize the microcapsules for the controlled release of Stavudine using cellulose acetate butyrate (CAB), ethyl cellulose (EC), hydroxy propyl methyl cellulose phthalate (HPMCP). The microcapsules were prepared by solvent evaporation method using acetone and liquid paraffin as a drug dispersion and liquid manufacturing phase, respectively. The prepared microcapsules were characterized for particle size distribution (PSD), percent drug content, entrapment efficiency, Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and in vitro dissolution studies. The prepared microcapsules were filled in hard gelatin capsules and kept for accelerated stability study as per ICH guidelines for about 3 months. The prepared microcapsules were spherical and free flowing. The entrapment efficiency was found to be 25-45%. The release of drug from the microcapsules was extended upto 12 hours and more. FTIR and DSC thermo graphs showed stable character of stavudine. Scanning electron microscopic study revealed that then microcapsules were spherical and porous in nature. The release kinetics study revealed that the prepared microcapsules were best fitted to the Higuchi model, first order and followed by Zero order and indicating that the drug release was diffusion controlled. The release was mainly influenced by the type of polymer and its viscosity. The DSC study revealed that there is no drug to polymer interaction and showed the stable character of the drug which was further confirmed by the assay of accelerated stability of microcapsules.