Medication container stopper which can be punctured by nozzle of a hypodermic syringe

Claim 1

An elastomeric stopper for a medication container, the stopper comprising: an elastomeric plug adapted to make a friction fit in an opening of the medication container, the plug having an exterior surface adapted to face away from the container interior and an interior surface adapted to face toward the container interior, the exterior surface of the plug having a cavity which opens and diverges away from the interior surface of the plug, the interior surface of the plug having a cavity which opens and diverges away from the exterior surface of the plug, each cavity having a bottom, the bottoms of the cavities being spaced apart so they are separated by, and define opposite faces of, a thin diaphragm formed integrally with the plug, one of the cavities having an elongated groove with a bottom which defines one face of the diaphragm, the bottom of the groove being substantially parallel to the other face of the diaphragm, and the diaphragm being of a thickness which permits the diaphragm to be ruptured by inserting a hypodermic syringe nozzle into one of the cavities; and a cylindrical bore extending from the exterior surface of the plug into the plug to merge with an outer portion of the cavity in the exterior surface of the plug to provide a guide for the nozzle of the hypodermic syringe.