Research and Application of Biodegradable Polymer Containing Poly(lactic acid) in Preparation of Drug Loaded Microspheres or Microcapsules

The research background and current status of biodegradable polymeric materials containing polylactic acid (PLA) for the preparation of the drug loaded microspheres or microcapsules are reviewed. The preparation methods of three different kinds of polymer materials are described in detail,including lactide ring-opening polymerization,polycondensation of lactic acid to prepare polylactic acid(PLA); copolymerization of lactide ring opening with glycolic acid to prepare poly(lactic acid-co-glycolic acid )copolymer (PLGA),polyethylene glycol monomethyl ether (mPEG) with lactide ring-opening or with lactic acid to prepare poly(lactic acid-co-polyethylene glycol monomethyl ether) diblock copolymer(mPEG-PLA).The microspheres' preparation and release mechanism and advantages of application in drug,especially polypeptide,micromocular proteins are also described. Main problems of application,especially the study and development in our country are introduced,and the prospect of these polymers is discussed.It's suggested that this kind of polymers will be one ofimportant drug delivery carrier of modern biological drug.