US Patent 7955619 Abuse resistant drugs, method of use and method of making

An abuse resistant oral pharmaceutical composition, comprising: a barrier layer, comprising a first polymer; a diffusion layer, comprising a second polymer, substantially covering the barrier layer, wherein the diffusion layer is bonded to the barrier layer and comprises a drug that is substantially homogeneously distributed within the second polymer and diffuses from the diffusion layer within the gastrointestinal (GI) tract; and optionally an expansion layer comprising an expandable polymer, wherein the expansion layer is substantially covered by the barrier layer. Methods of making the same and methods of using the same are also provided.