Preparation and In Vitro Release Property of PLA Microspheres Enclosing Antitumor Agent

Recently, many antitumor agents developed. Irinotecan hycrochloride (CPT) has a great side effect even though it is well effective against the cancer. Drug delivery system (DDS) medicine indicates that the release rate of medicine is constant for a long time. Therefore, in order to materialize the general idea of DDS, we applied microencapsulation technique to prepare biodegradable polymer microspheres (MS) enclosing antitumor drug having no side effect. Polylactide microparticles enclosing antitumor agent were prepared by solvent evaporation method under various operation conditions. The effects of operation parameter on release rate of drug and morphology of microparticles were studied

Preparation of Monodispersed Hydrophilic Polymer Microspheres in Gel Permeation Chromatography

Monodispersed porous polymer microspheres having diameter of ca. 50 μm were successfully prepared by suspension polymerization of styrene, polyoxyethylene methacrylate and ethylenegycol dimethacrylate. Monodispersed O/W emulsion was firstly made by SPG membrane emulsification technique, following droplets-swelling method of monodispersed seed emulsion by the addition of secondary emulsion. The effect of solvent used in suspension polymerization on porous structure of prepared polymer microspheres was investigated in this paper by identification with scanning electron microscopy, porosimeter and the performance in gel permeation chromatography. It was found that benzene, 1-butanol and butyl acetate worked as poor solvent for polymer prepared in this study and that polymer microspheres prepared with these solvents had larger pores. Gel permeation chromatography measurements indicates that polystyrene having molecular weight smaller than 50,000-100,000 can be clearly separated by using gel columns packed with polymer microspheres prepared with poor solvents