Patent attributes
A syringe system for the administration of lyophilized drugs includes a syringe barrel and a stopper and a needled guard each coupled with the syringe barrel. A reconstitution plunger is removably coupled with the stopper. A diluent is withdrawn from the syringe into a vial containing a lyophilized drug, and the diluent and drug are mixed to form a therapeutic agent. The reconstitution plunger is then replaced by an administration plunger. The length of the reconstitution plunger is greater than the length of the administration plunger in order to prevent activation of the needle guard during reconstitution. Alternatively, a single plunger system may be used in which the plunger can transition from an extended length during reconstitution to a shortened length during administration. During administration, a radial element of the plunger contacts latch members of the needle guard, whereupon the shield advances to an extended position covering the needle.
