the present invention provides a simple and improved multi - layered osmotic device that is capable of delivering a first active agent in an outer lamina to one environment of use and a second active agent in the core to another environment of use . particular embodiments of the invention provide osmotic devices in which the first and second active agents are similar or dissimilar . an erodible polymer coat between an internal semipermeable membrane and a second active agent - containing external coat comprises poly - copolymer . this particular erodible polymer results in an improved multi - layered osmotic device possessing advantages over related devices known in the art . the active agent in the core is delivered through a pore containing an erodible plug . the osmotic device can be coated by a final finish coat .