VARIABLES EFFECTING DRUG ENTRAPMENT EFFICIENCY OF MICROSPHERES: A REVIEW

Abstract

Microspheres are characteristically free flowing powders consisting of proteins or synthetic polymers which are biodegradable in nature and ideally having a particle size less than 200 μm. A well designed microsphere can overcome such problems by enhancing the loading efficiency of a particular drug and minimizing the wastage of drug. 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. For success of microspheres as drug delivery system its necessary to obtained desired particle size, maximum drug entrapment, mucoadhesion, swelling index and drug release. This can be obtained by optimizing the formulation as well as process variables but before designing the microspheres formulation deep understanding the effect of various variables on characteristics of microspheres is necessary. The intent of the paper is to highlight the reported study on various formulation variables those are might be useful to encountered several problems which is reason for low drug entrapment efficiency