AN OVERREVIEW ON MICROSPHERES PREPARATION AND EVALUATION METHODS

The concept of targeted drug delivery is designed for attempting toconcentrate the drug inthe target tissues of interest while reducing the relativeconcentration of the medication in the remaining tissues i.e., other than target tissues, so that the drugis localized on the targeted site. Hence, other/surrounding tissues are notaffected by the drug. So, carrier technology offers an intelligent approachfor drug delivery systems by coupling the drug into carrier particles such asmicrospheres, nanoparticles, liposomes, niosomes etc., which modulatesthe release and absorption characteristics of the drugs. Microspheres arecharacteristically free flowing powders consisting of proteins or syntheticpolymers which are biodegradable in nature and ideally having a particlesize less than 200 μm. It is the reliable means to deliver the drug to thetarget site with specificity, if modified and to maintain the desiredconcentration at the site of interest without untoward effects.Microspheres received much attention not only for prolonged release, butalso for targeting of anticancer drugs to the tumour. In future by combining various otherstrategies, microspheres will find the central place in novel drug delivery systems, particularly indiseased cell sorting, diagnostics, gene & genetic materials, safe, targeted and effective in-vivo delivery and supplements as miniature versions of diseased organ and tissues in thebody.