A syringe assembly comprising a barrel 12 for containing one or more medicaments； at that, the barrel has front outlet 12a for allowing the expulsion from the said barrel through said outlet, and a first stopper 14 disposed in the barrel and axially moveable therein and defining a first volume 16 in the barrel axially forwards of the first stopper and a second volume 18 in the barrel axially rearwards of the first stopper. At that, the two way valve is moveable from the sealing configuration to the open configuration by an increase in fluid pressure in either of the first and second volumes. The syringe assembly additionally comprises a second stopper 20 disposed in the barrel axially rearward of the first stopper and axially moveable therein, the second stopper providing a fluid tight seal at a rear end of the second volume. The syringe assembly further comprises a first plunger rod 22 connected to the first stopper and extending axially rearwardly through the second stopper, the second stopper sealingly engaging with the first plunger rod but permitting axial sliding of the first plunger rod therethrough. At that, the first plunger rod is axially moveable so as to axially move the first stopper and pressurise either of the first volume and second volume causing the two way valve to move into the open configuration and fluidly connect the first volume and second volume.
