Multi-Compartment Pre-filled Mixing Syringes with Bypass

A multi-compartment medical device for segregated storage and on demand mixing of at least two components and expression of a resulting mixture from the device, comprising:

• a) a tubular barrel extending along an axis and having a front end and a rear end spaced axially behind the front end wherein the front end has an opening to express the mixture and a removable cap on said opening;
• b) a gasket sealing the rear end of the tubular barrel and having an aperture;
• c) a plunger located between the gasket and front end that is axially slidable within the tubular barrel that subdivides the tubular barrel into a front compartment between the plunger and the opening and a rear compartment between the plunger and the gasket;
• d) a stem attached to the plunger and projecting axially rearward out of the rear end through the gasket, said stem sealing the aperture and axially slidable through the gasket aperture;
• and
• e) at least one bypass in the barrel that is positioned between the front end and the rear end of the tubular barrel so as to enable fluid movement of the components between the front compartment and rear compartment;
• wherein the plunger and the rear compartment are located axially behind the front compartment.