Patent attributes
A syringe assembly for use as a pre-filled syringe is disclosed. The syringe assembly includes a syringe barrel defining a chamber and having a stopper disposed therein. A plunger rod includes an inner member engaged with a portion of the stopper and an outer member adapted for rotational advancement with respect to the inner member to axially displace the outer member with respect to the inner member. The plunger rod is transitionable from a collapsed position in which a portion of the inner member is nested within the outer member, to an extended position in which the same portion of the inner member extends outside the outer member. The inner member includes a radial extension and the outer member defines a helical track adapted to receive the radial extension therein.