A controlled release device useful especially as an oral dosage form for man comprises a water impermeable capsule having at least one orifice which orifice is closed by a water swellable or water dispersable plug. Preferably the capsule is a cylinder formed e.g. of polyethylene closed at one end. The...http://www.google.es/patents/US5474784?utm_source=gb-gplus-sharePatente US5474784 - Dispensing device
