Abstract: A self-displacing separator disc is positioned transversely of a tubular member to form a seal in the bore of the member, which may be a hypodermic syringe, to provide two or more separate chambers containing material which is to be kept separated until use thereof. The separator disc is constructed to respond differentially to force or pressure on one side thereof by having peripheral regions of different frictional response with respect to the bore wall such that the disc is displaced out of a transverse orientation upon exposure to force or pressure. Various different structures of discs are described to achieve self-displacement of the disc in a bore which preferably has a uniform internal diameter along its effective length.

Abstract: A multiple barrel hypodermic syringe is provided for mixing materials contained in the barrels prior to use. A typical two barrel syringe comprises a lower barrel for containing a sterile material such as a lyophilizable product, and an upper barrel containing a liquid diluent. The two barrels can be completely disengaged for separate replacement, alteration or reconstitution, etc., of their contents, if necessary.One or more slot vents are provided along either barrel to enable release of air, gas, moisture, etc., within the lower barrel when they are partially engaged. Upon further engagement in a sterile environment, the slot vents will be totally occluded by the mating surfaces of the two barrels; this enables the syringe to be sealed and the contents stored for future use.The hypodermic syringe of this invention also enables a lyophilization process to be carried out in situ followed by storage.