Prefilled syringe

摘要

A prefilled syringe has a gasket composed of a gasket body and a plunger-mounting member mounted. The plunger-mounting member has a distal part, spiral ribs formed on an outer surface of the distal part, a flange part, and a plunger-mounting part formed on an inner surface of a hollow part. The gasket body has a spiral screwing part which screws the spiral ribs and an accommodation part for accommodating a portion where the spiral ribs are formed. A plunger has a mounting distal part. The plunger-mounting part has a spiral concave portion and an engaging rib disposed at a side distal from the spiral concave portion. The mounting distal part of the plunger has a spiral projected portion capable of screwing the spiral concave portion and an engaging portion which engages the engaging rib of the plunger-mounting member.

主权项

1. A prefilled syringe comprising:
a prefilled syringe body including an outer cylinder, a gasket slidably accommodated inside the outer cylinder, a sealing member sealing an opening at the distal end of the outer cylinder, and medicine accommodated inside the outer cylinder; a plunger to be attached to the gasket at the time of use of the prefilled syringe; the gasket comprising a gasket body and a plunger-mounting member mounted on the gasket body, the gasket body possessing a closed distal end, an open proximal end and a lumen part provided in the gasket body, the gasket body including a spiral projection provided at a proximal portion of an inner surface of the gasket body; the plunger-mounting member comprising a body part, a distal side flange part provided at a distal portion of the body part and configured to press against a proximal end surface of the gasket body, a distal part projecting distally from the distal side flange part, a spiral rib provided on an outer surface of the distal part and adapted to the spiral projection of the gasket body, a proximal side flange part at a proximal end of the body part; and a plunger-mounting part inside a proximal portion of the body part; the lumen part of the gasket body including an accommodation part disposed distally from the spiral projection for accommodating a portion of the plunger-mounting member at which is located the spiral rib of the plunger-mounting member; the plunger including a pressing part for pressing a proximal end surface of the proximal side flange part of the plunger-mounting member, and a mounting distal part projecting distally from the pressing part and configured to enter the plunger-mounting part of the plunger-mounting member; the plunger-mounting part of the plunger-mounting member including an engaging rib and a spiral concave portion located between the proximal side flange part and the engaging rib; the mounting distal part of the plunger including an engaging portion which engages the engaging rib of the plunger-mounting member and a spiral projected portion configured to screw engage the spiral concave portion of the plunger-mounting member and located between the pressing part and the engaging portion; a distance between the proximal side flange part and a distal end of the engaging rib of the plunger-mounting member is approximately the same as a distance between the pressing part and a proximal end of the engaging portion of the plunger; and the mounting distal part of the plunger does not contact the inner surface of the gasket body when the plunger is attached to the gasket.