抄録
Ethylene-vinyl acetate (EVA) copolymer was evaluated as a carrier for controlled release of 5-fluorouracil (5-FU). In order to study the effect of comonomer ratio modifications on the drug release kinetics, the release of 5-FU dispersed in polymer matrices composed of different ratios of ethylene and vinyl acetate was investigated. The vinyl acetate content of EVA copolymer was varied from 8 to 40% w/w. An increase in vinyl acetate comonomer content increased the drug release from the polymer matrix. The release rate could be controlled by modifying the ethylene/vinyl acetate ratios in the polymer matrices. The antitumor activity of EVA copolymer matrices containing 5-FU was evaluated against Ehrlich ascites carcinoma in mice, on the basis of changes in body weight and animal survival data. Tumor cell injections were performed on Day 0 and matrix implantations on Day 4, both intraperitoneally. The suppressive effect of matrices containing 5-FU on the increase in body weight was higher than that of the free drug. A prolongation of the life-span of tumor-bearing mice following implantation of therapeutic matrices was also noted. These results indicated that EVA matrices containing 5-FU may be effective in cancer chemotherapy. Matrices composed of EVA copolymer could be useful vehicles for implanted, inserted, or surface-applied delivery systems for anticancer agents.
