POLYMER DRUGS AND POLYMERIC DRUGS X - SLOW-RELEASE OF 5-FLUOROURACIL FROM BIODEGRADABLE POLY(GAMMA-GLUTAMIC ACID) AND ITS BENZYL ESTER MATRICES

We prepared poly(gamma-glutamic acid)(gamma-PGA) benzyl ester(gamma-PB G) by the esterification of gamma-PGA and benzyl bromide and evaluated the degradation behavior and its usefulness as a drug delivery system (DDS) matrix using B-fluorouracil (5-FU) as a model drug. gamma-PBG d egraded in an acidic solution gradually for up to 130 days, and degrad ed very slowly in a phosphate buffer solution (pH 7.4). After 150 days , the weight loss of the gamma-PBG film was only 10% in a phosphate bu ffer solution. A slow release of 5-FU from gamma-PBG films was achieve d. The release rate was affected by the pH of the outer solution and t he loading drug. We observed an initial burst-release on the first day , after that, the release of 5-FU was diffusion-controlled gamma-PBG m ay be a novel biodegradable material that may be useful in the pharmac eutical, biomedical, and agricultural fields.