Microsphere as a novel drug delivery

Abstract

Microspheres are spherical & free flowing particles ranging in average particle size from 1 to 50 microns which consist of proteins or synthetic polymers. Some of the problems of overcome by producing control drug delivery system which enhances the therapeutic efficacy of a given drug. One such approach is using microspheres as carriers for drugs. The target site drug deliver with Specificity & maintain the the concentration at site of interest without untoward effects. It will find the central place in novel drug delivery. Drugs can be targeted to specific sites in the body using microspheres. Degree of targeting can be achieved by localization of the drug to a specific area in body (for example in lungs), to a particular group of cells (for example, kupffer cells) and even to the intracellular structures (as lyzosomes or cell nucleus). The rate of drug release from the microspheres dictates their therapeutic action. Release is governed by the molecular structure of the drug and the polymer, the resistance of the polymer to degradation, and the surface area along with the porosity of the microspheres. The internal structure of the microspheres can vary as a function of the microencapsulation process employed. Controlled drug release from microspheres occurs by diffusion of the drug through a polymeric excipient, diffusion of the entrapped drug through the pores in the polymeric microspheres.