Abstract: A prefilled syringe has a tubular body which has an open front end and an open rear end. A front assembly is mounted on an outer periphery of a front end portion of the tubular body. A finger grip is mounted on an outer periphery of a rear end portion of the tubular body. A front sealing member is provided in the tubular body so as to be disposed forwardly of injection liquid and a rear sealing member is provided in the tubular body so as to be disposed rearwards of the injection liquid. A plunger rod is provided so as to be movable in the tubular body. A temporary stop member temporarily stops the plunger rod through retention of the temporary stop member by the finger grip such that the rear sealing member is temporarily stopped at a predetermined position of the tubular body. A retention canceling member cancels the retention of the temporary stop member by the finger grip without moving the plunger rod.

Abstract: A two-compartment type prefilled syringe includes a first rubber stopper fitted into a front sleeve, a second rubber stopper fitted into a rear end portion of a cartridge, a third rubber stopper for hermetically dividing the interior of the cartridge into front and rear compartments and a bypass formed by radially outwardly bulging a portion of a peripheral wall of the cartridge. In an axial direction of the cartridge, a length of the third rubber stopper is slightly smaller than an inner length of the bypass. When the third rubber stopper has been displaced into the bypass, the sealing property of the rear compartment with the front compartment is cancelled such that the dissolving agent, suspension or the like in the rear compartment is carried, via the bypass, into the front compartment containing dry medicament or the like.

Abstract: The present invention relates to a prefill syringe in which the space provided at the joining area between a cap or protector and a needle holder can be covered by an inexpensive material and a simple method, without interrupting the flow of the production process. In this prefill syringe, a cap 15 or a protector is attached to a needle holder 11 provided to one end of cartridge 10, and a cylindrical member 20 formed of an elastic material is externally engaged to span the needle holder and cap or protector so as to cover the joining area A between the needle holder and the cap, or the joining area between the needle holder and the protector. Further, one or more ring-shaped projections which contact the outer peripheral surface of the needle holder and the outer peripheral surface of the cap are formed to the inner periphery of the cylindrical member.