Antitumor effect of implanted ethylene-vinyl alcohol copolymer matrices containing anticancer agents on Ehrlich ascites carcinoma and P388 leukemia in mice.

Abstract
Ethylene-vinyl alcohol (EVA1) copolymer was evaluated as a vehicle for controlled or sustained release of 5-fluorouracil (5-FU) and adriamycin. The variation of initial drug concentration and, to an even greater extent, the variation in comonomer ratio, affected the drug release rate as well as the cumulative amount of the drug released. An increase in the ethylene content of the EVA1 copolymer decreased drug release. EVA1 copolymer can apparently be used as a membrane for controlling the release of 5-FU or adriamycin. The antitumor activity of EVA1 copolymer matrices containing these anticancer agents was evaluated against Ehrlich ascites carcinoma (EAC) 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 3, both i.p. The suppressive effect of matrices containing anticancer agents on the increase in body weight was higher than that of the free drugs. A prolongation of the life span of tumor-bearing mice following implantation of therapeutic matrices was also noted. Implantation of the EVA1 copolymer matrix containing an anticancer agent was less effective against the P388 leukemia than the EAC. EVA1 copolymer matrices containing anticancer agents may be effective in cancer chemotherapy. Matrices composed of EVA1 copolymer could be useful vehicles for implanted delivery systems for anticancer agents.