Abstract
The aim of this work was to formulate and evaluate controlled-release oxypentifylline (OXP) microspheres that fulfill the requirements for extended release medications using Ammonio Methacrylate Copolymer RS100 as polymeric material. The microspheres were prepared by quasi-emulsion solvent diffusion technique. The effect of process variables such as a drug to polymer ratio, stirring rate, and concentration of emulsifier on mean particle size, yield, entrapment efficiency and in-vitro release characteristics of microspheres were studied. The prepared microspheres were spherical in shape. The size range varied from 325.45 to 518.54 mu m. The microspheres showed high entrapment efficiency (94.22%) and the drug release was extended up to 24 h. The optimum microsphere formulation was selected and subjected for in-vivo studies, which revealed that the bioavailability of the drug from the prepared microspheres was increased by more than 3.4 times. This study showed that Ammonio Methacrylate Copolymer RS100 can be used successfully to sustain the release of OXP.