FROM FORMULATION VARIABLES TO DRUG ENTRAPMENT EFFICIENCY OF MICROSPHERES: A TECHNICAL REVIEW

Purpose of writing this review on microspheres was to compile the recent literature with special focus on formulation variables which affect the drug entrapment efficiency of microspheres. There are various approaches in delivering a therapeutic substance to the target site in a controlled release fashion. One such approach is using microspheres as carriers for drugs. Microencapsulation is used to modify and delayed drug release form pharmaceutical dosage forms. 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