Design, Development and Characterization of Valsartan Microsponges by Quasi Emulsion Technique and the Impact of Stirring Rate on Microsponge Formation

Microsponges are highly cross linked, patented, porous polymeric microparticles and each particle consists of a myriad of interconnected voids within a non-collapsible structure. Moreover, they may enhance stability, reduce side effects and modify drug release favourably. They are designed to deliver a pharmaceutical active ingredient efficiently at the minimum dose and also to enhance stability reduce side effects and modify drug release. The rationale behind present work was to formulate valsartan entrapped micro porous micro particles (microsponges) to control the release of the drug. Valsartan microsponges was prepared using quasi emulsion solvent diffusion method. In order to optimize the micro sponge formulation, factors affecting the physical properties of micro sponges were determined. Compatibility of the drug with excipients was studied by FT-IR, Production yield, loading efficiency and surface morphology of microsponges were performed. It was shown that the drug: polymer ratio and stirring rate influenced the particle size and drug release behaviour of micro sponges. The results showed that, generally an increase in the ratio of the drug: polymer and stirring rate resulted the cumulative percentage drug release up to 8 hrs for M7, M8, M9 were 72%, 89% and 94% respectively and entrapment efficiency values of 33.8 - 84.5 respectively.