Albumin Microspheres: effect of process Variables on size Distribution and in Vitro Release

Abstract

Albumin microspheres used as target drug delivery systems were prepared from egg albumin by polymerization technique using glutaral dehyde as the cross linking agent. The present study was designed to evaluate the effect of process variables on the nicrosphere size distribution and in vitro drug release. Phase volume ratio and speed of agitation exerted greater influence on the microsphere size distribution whereas the albumin concentration and cross linking time effected only the yield and surface characteristics of the microspheres respectively. Lower phase volume ratios resulted in small and uniform microspheres with smooth surfaces in narrow size range. Speed of agitation exhibited an inverse relationship with size. In vitro release pattern of drug from the microspheres showed a biphasic profile and the release rates were prolonged upon increase in the concentration of cross linking agent and cross linking time.