Microspheres - A Novel Drug Delivery System: An Overview

Microspheress are characteristically free flowing powders consisting of proteins or synthetic polymers which are biodegradable in nature. Microspheress are particles between 0.1 and 200μm in size. A well designed controlled drug delivery system can overcome some of the problems of conventional therapy and enhance the therapeutic efficacy of a given drug. There are various approaches in delivering a therapeutic substance to the target site in a sustained controlled release fashion. A Microspheress has its drug dispersed throughout the particle i.e. the internal structure is a matrix of drug and polymeric excipients It is the reliable means to deliver the drug to the target site with specificity, if modified, and to maintain the desired concentration at the site of interest without untoward effects. Microspheress received much attention not only for prolonged release, but also for targeting of anticancer drugs to the tumour. Microsphere are spherical microparticles, and are used where consistent and predictable particle surface area is important. . A microspheres has a drug located centrally within the particle, where it is encased within a unique polymeric membrane. In future by combining various other strategies, microspheres will find the central place in novel drug delivery, particularly in diseased cell sorting, diagnostics, gene & genetic materials, safe, targeted and effective in vivo delivery and supplements as miniature versions of diseased organ and tissues in the body.