Abstract
The use of ethylcellulose microcapsules possessing a reservoir system to achieve sustained release of sulfamethizole or 5-fluorouracil was examined in vitro. As a first step, the drugs were dispersed in cellulose acetate matrices, then the matrices were microencapsulated by means of coacervation-phase separation of ethylcellulose from diethyl ether solution by nonsolvent addition. The surfaces of microcapsules were rounded, whereas the milled matrices were sharp-edged. In microcapsules of both drugs, longer release half-lives were obtained than with the corresponding matrices.
