Polymer drugs and polymeric drugs X:: Slow release of 5-fluorouracil from biodegradable poly(γ-glutamic acid) and its benzyl ester matrices

We prepared poly(gamma-glutamic acid)(gamma-PGA) benzyl ester(gamma-PBG) 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 degraded in an acidic solution gradually for up to 130 days, and degraded 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 buffer solution. A slow release of 5-FU from gamma-PBG films was achieved. The release rate was affected by the pH of the outer solution and the loading drug. We observed an initial burst-release on the first day, after that, the release of 5-FU was diffusion-controlled gamma-PBG may be a novel biodegradable material that may be useful in the pharmaceutical, biomedical, and agricultural fields.