NEW CONTROLLED RELEASE BEAD, A METHOD OF PRODUCING THE SAME AND MULTIPLE UNIT FORMULATION COMPRISING IT

摘要

A controlled release bead comprises: (i) a core unit of a substantially wate r- soluble or water-swellable inert material; (ii) a first layer on the core unit of a substantially water-insoluble polymer; (iii) a second layer covering the first layer and containing an active ingredient; and (iv) a third layer of polymer on the second layer effective for controll ed release of the active ingredient, wherein the first layer is adapted to control water penetration into the core. A method of producing th e controlled release bead is also disclosed.