Device for introduction of liquid medication into a flexible bag

A device for the introduction of liquid medication into a flexible bag for intravenous solution, said bag having extending from the top thereof an additive-receiving flexible tube-like orifice and an outlet adapted to lead to an intravenous solution set, said device comprising an elongated generally cylindrical hollow tubular member having an open end and a closed end, a boss extending from said closed end, carried by the boss a cannula having a sharpened outer end, a rigid cylindrical sheath of fixed length surrounding said cannula and affixed to said boss, said sharpened outer end extending slightly beyond the free end of said sheath, said orifice having a diameter greater than that of said cannula, said sharpened outer end being adapted to be received in said flexible tube-like orifice and said sheath being adapted to engage said orifice to limit the advancement of said cannula into the orifice;

• within said tubular member, a thrust portion, a fluid passage extending longitudinally through the center of said thrust portion, the lower end of said fluid passage communicating with the upper end of said cannula at said boss, a cylindrical vial having a resilient stopper in its open end sealing on the inside walls of said vial, interlocking means on said thrust portion and cooperating interlocking means on said stopper, whereby upon interlocking of said plug with said thrust portion said vial is first held in an assembled but non-operating position and upon further interlocking of said plug with said cylindrical member, said plug is adapted to be pierced by said fluid passage and said fluid passage communicated with said vial without the application of substantial axial pressure on said plug and said plug is locked securely to said cylindrical member to permit aspiration upon withdrawal of said vial or to permit expulsion of the contents of said vial upon exertion of pressure on said vial.