Patent ID: 8163306

Claim:
An orally administerable drug delivery system comprising: (1) a core comprising one or more active ingredient composition layers and one or more separate swellable composition layers, the one or more active ingredient composition layers comprising at least one pharmaceutically active ingredient and one or more pharmaceutically acceptable excipients, wherein in at least one active ingredient composition layer, at least one pharmaceutically acceptable excipient is a rate controlling excipient, and (2) a water insoluble polymer coating surrounding the core; wherein one or more of the swellable composition layers is located in an immediate vicinity of one or more preselected portions of the coating in order to be in communication with said preselected portions of the coating, and the one or more active ingredient composition layers are in the vicinity of another portion of the coating; wherein the water insoluble polymer coating comprises one or more passageways through the preselected portions of the coating, said one or more passageways penetrating to at least one swellable layer; and wherein the at least one or more preselected portions of the coating that is in communication with the swellable layer and has a passageway is removed after contact with an aqueous environment and wherein the remaining portion of the coating is not removed.