Abstract
Ethylene-vinyl alcohol (EVAl) 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 alcohol was investigated. The ethylene content of EVAl copolymer was varied from 32 to 60 mol%. An increase in ethylene comonomer content decreased the drug release from the polymer matrix. The release rate could be controlled by modifying the ethylene/vinyl alcohol ratios in the polymer matrices. Fabrication parameters such as drug content and surface area of matrices also affected the release kinetics. The release rates were shown to be proportional to release media temperature, but independent of the pH. Matrices composed of EVAl copolymer appeared to be stable on long-term storage with respect to release rate and could be useful vehicles for the controlled release of hydrophilic drugs.
