Drug delivery system of microspheres can realize the target delivery of drugs .They exhibit a good prospects in the sustained-release and controlled-release drug delivery systems .In recent years

the application of pharmaceutical microspheres had been one of the research focus .Polymer carriers are developmented with pharmacology

biomaterials and clinical medicine

they are pharmaceutical excipients which possess excellent biocompatibility

biodeg radability

processing property and meeting safty standard .They include ethyl-cellulose

starch

chitosan

alginate

gelatin

silk fibroin

albumin

zein

PLA and PLGA .Currently

the application of polymer carriers on the pharmaceutical microspheres is attractive to the pharmacists .Based on the degradability

the polymer carriers can be divide into non-degradable and degradable polymer .This review summarizes the application and advances on the different types of polymer carriers for the pharmaceutical microspheres .