No abstract

We prepared poly(γ-glutamic acid)(γ-PGA) benzyl ester(γ-PBG) by the esterification of γ-PGA and benzyl bromide and evaluated the degradation behavior and its usefulness as a drug delivery system (DDS) matrix using 5-fluorouracil (5-FU) as a model drug. γ-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 γ-PBG film was only 10% in a phosphate buffer solution. A slow release of 5-FU from γ-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. γ-PBG may be a novel biodegradable material that may be useful in the pharmaceutical, biomedical, and agricultural fields.

A conjugate of poly(y-glutamic acid)(y-PGA) with 5-fluorouracil (5-FU) (y-poly(a-hydroxymethyl-5-fluorouracil-glutamate)), y-PFUG, was prepared as a polymeric prodrug matrix. The release of 5-FU and the degradation behavior of y-PFUG, which is soluble in polar organic solvents were studied. y-PFUG films were prepared by casting from DMF. The y-PFUG matrix degraded in 7 days and incorporated 5-FU was released in 3 days. 5-FU release was accelerated by mixing free 5-FU into y-PFUG. Here, y-PFUG functioned as a hydrophobic degradable matrix. Analogous with y-PFUG, y-PGA conjugated with a drug may be useful as a biodegradable polymeric prodrug.