Patent ID: 8394052

Claim:
A plunger-barrel apparatus for use in a syringe-in-syringe mixing system adapted for mixing a two-part composition, the plunger-barrel apparatus comprising: a hollow plunger-barrel body sized and configured for insertion into a syringe barrel and having a continuous wall defining an internal chamber for containing a composition therein, the hollow plunger-barrel body having a plunger receiving end and a dispensing end, the plunger receiving end having an opening sized and configured for receiving therethrough a sealing plug of an auxiliary plunger; and an integrally formed sealing plug and rupturable membrane disposed over the dispensing end of the hollow plunger-barrel body, the integrally formed sealing plug and rupturable membrane including: a sealing plug portion laterally disposed around the dispensing end of the hollow plunger-barrel body and having a distal end that terminates at or near an opening through the dispensing end and an outer surface that is adapted to sealingly engage against an inner surface of the syringe barrel into which the hollow plunger-barrel body is sized and configured to be inserted; and a rupturable membrane portion integrally formed with the distal end of the sealing plug portion, the rupturable membrane portion having a cross-sectional thickness that is substantially less than a cross-sectional thickness of the sealing plug portion to facilitate rupture of the rupturable membrane portion during use, the rupturable membrane portion providing a continuous sealing barrier across the distal end of the sealing plug portion so as to cap and seal off the dispensing end of the hollow plunger-barrel body and prevent passage of a composition through the dispensing end until irreversible rupture of the rupturable membrane portion through application of sufficient pressure to a composition contained within the internal chamber so as to irreversibly rupture the rupturable membrane portion.