prolonged release [Gk, pro, before, longus, long] , a term applied to a drug that is designed to deliver a dose of a medication over an extended period. The most common device for this purpose is a soft, soluble capsule containing minute pellets of the drug for release at different rates in the GI tract, depending on the thickness and nature of the oil, fat, wax, or resin coating on the pellets. Another system consists of a porous plastic carrier impregnated with the drug and a surfactant to facilitate the entry of GI fluids that slowly leach out of the drug. Ion exchange resins that bind to drugs and liquids containing suspensions of slow-release drug granules are also used to provide medication over an extended period. Various mechanisms and vehicles have also been developed to prolong the release of drugs after injection. Also called timed release.
