Injector

Abstract

There is provided a injector in which a backstop function is realized by a collar part at a position situated away from a gasket in the direction of the side of the proximal end and adequate sterilization can be carried out, with a plunger rod (in which the collar part is formed) assembled, while aiming to secure airtightness. (A backstop function is realized by means of a collar part at a position situated away from the gasket in the direction of the side of the proximal end, thereby providing a injector capable of being adequately sterilized with a plunger rod (in which the collar part is formed) assembled, while aiming to secure airtightness.) A gasket (3) is inserted from a proximal end opening (22) of a barrel (2). Next, a plunger rod (4) is inserted as to establish connection of its distal end and the gasket (3). Then, a finger grip (5) is mounted to a flange (23). A disc part (45) is formed at a position situated away, in the direction of the side of the proximal end, from the gasket, thereby making it possible for the disc part (45) to abut and stop against an aperture edge (521) of the finger grip. There is formed in an outer peripheral edge part of the disc part (45) a communication opening part (451) having a concave shape. At the time of sterilization with hydrogen peroxide gas, the hydrogen peroxide gas which has flowed into an open space (26) from the proximal end opening is permitted to circulate in a semi-hermetically closed space (25) by way of the communication opening part.

Description

technical field [0001] The present invention is aimed at a syringe with a back stop function. In particular, the present invention relates to a syringe that can be favorably sterilized with a plunger rod inserted into a barrel and a back-stopper attached. The backstop function is a function for preventing the plunger from falling out of the barrel of the syringe. The function of the backward stopper is to form a flange on the plunger rod. On the other hand, after the plunger rod is inserted into the syringe, the backward stopper for stopping the flange is assembled in the syringe. On the base end side, even if the entire plunger rod is intended to be drawn out from the barrel, the flange portion abuts against the retraction stopper and cannot be drawn out. Background technique [0002] Conventionally, a sterilization treatment using hydrogen peroxide gas has been proposed as a sterilization treatment for a drug solution-filled syringe (pre-filled syringe) filled with a dru...

AI Technical Summary

Problems solved by technology

Therefore, it can be seen that for the area between the base end opening of the syringe and the above-mentioned flange part, although the hydrogen peroxide gas can easily enter the interior of the syringe from the gap between the base end opening of the syringe and the plunger rod cross section, However, the existence of the flange portion makes it difficult for hydrogen peroxide gas to enter the above-mentioned substantially airtight space closer to the front end than the flange portion.

When this happens, there is a possibility that the sterilization of the inner peripheral surface of the syringe or the outer peripheral surface of the plunger rod existing in the axial region from the above-mentioned piston to the flange part may be insufficient.

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