Characterizations and Release Behavior otPoly[(R)-3-hydroxy butyrate]-C0-Methoxy Poly(ethylene glycol)with Various Block Ratios

摘要

Poly[(R)-3-hydroxy butyrate](PHB)and methoxy poly(etbylene glycol)(mPEG)were conjugated by the transesterification reaction with tin(II)-ethylhexanoate(Sn(Oct)-II)as a catalyst.Hydrophobic PHB and hydrophilic mPEG formed an amphiphilic block copolymer which was formed with the self-assembled polymeric micelle in aqueous solution.In this study,we tried to determine the optimum ratio of hydrophobic/hydrophilic segments for controlled drug delivery.The particle size and shape of the polymeric micelle were measured by atomic force microscopy(AFM)and transmission electron microscopy(TEM).Their size were 61-102 nm with various block ratios.Griseofulvin was loaded in the polymeric micelle as a hydrophobic model drug.The loading efficiency and release profile were measured by high performance liquid chromatography(HPLC).The model drug in our system was constantly released for 48 h.