Gastric retention dosage form having multiple layers

摘要

The present invention is directed to a multilayered dosage form which is adapted for retention in the stomach and useful for the prolonged delivery of an active agent to a fluid environment of use. The active agent dosage form is a multilayer core, often bilayer, formed of polymer matrices that swell upon contact with the fluids of the stomach. At least one layer of the multilayered dosage form includes an active agent. A portion of the polymer matrices are surrounded by a band of insoluble material that prevents the covered portion of the polymer matrices from swelling and provides a segment of the dosage form that is of sufficient rigidity to withstand the contractions of the stomach and delay expulsion of the dosage form from the stomach until substantially all of the active agent has been dispensed.