(of a drug or fertilizer) capable of gradual release of an active agent over a period of time, allowing for a sustained effect; timed-release; long-acting; prolonged-action; slow-release.
Main Entry: sus·tained–re·lease Pronunciation: s&s-"tAnd-ri-"lEs Function: adjective : designed to slowly release a drug in the bodyover an extended period of time <sustained–release capsules> sustained–release drug delivery system> —compare TIMED-RELEASE
[suh-steynd-ri-lees] 
