Role of Microspheres in Drug Delivery-An Overview

From the last two decades, pharmaceutical scientists are developing the microspheres, free flowing powdered advanced drug delivery systems, not only as carrier systems to deliver different drugs at the controlled rate, but also to gain the therapeutic benefit to treat different diseases like cancer and growth disorders and also for radiological applications. Pharmaceutically, microspheres are solids; approximately spherical particles ranging in size from 1-1000 µm. They are made up of polymeric substances, in which the drug is dispersed throughout the microspheres matrix. Microspheres, due to high surface area and low particle size significantly increase the absorption rate and bio-availability. They are also useful to provide the controlled release or sustained release and site specific drug delivery. In future by combining various other strategies microsphere will find a central place in advanced drug delivery, particularly in diagnostics, diseased cell sorting, gene and genetic material delivery, targeted and effective in-vivo delivery. The present review explains the methodology of preparation of microspheres, method of evaluation and their recent applications and also updates the recent research on microspheres.