JP2013070789A - Plunger for syringe, syringe and prefilled syringe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plunger for a syringe for reducing mounting resistance when screwing and mounting a plunger body to a gasket, facilitating mounting work, and preventing rotation of the gasket during the mounting work.SOLUTION: The plunger 1 for a syringe includes a gasket 2 having a luminal part 21, and a plunger body 3. The plunger body 3 includes a plate part 36 provided on a body part 30, a distal end part 31 which can be housed in the luminal part 21 of the gasket 2, a plunger side screw part 32 provided on the outer surface of the distal end part 31, and a rotation regulating rib 35 provided on the plate part and projected in a distal end direction. The gasket includes a spiral screw part 24 provided on the inner surface of the luminal part to be screwed with a spiral rib, a rib housing recessed part 25 capable of housing the rotation regulating rib 35, and an easy-to-deform part provided on a side part of the rib housing recessed part.

Description

  The present invention relates to a plunger for a syringe having a mechanism for preventing a plunger main body from coming off from a gasket, a syringe using the same, and a prefilled syringe.

Recently, many prefilled syringes pre-filled with a chemical solution have been used. In the prefilled syringe, the gasket is inserted in a state where the medicine is filled in the outer cylinder whose tip opening is sealed, and the gasket is placed in the opening of the outer cylinder in an atmosphere under reduced pressure (vacuum atmosphere). It is common to use a so-called vacuum plugging method in which the gasket is inserted into the outer cylinder by setting the state. When the plunger is already attached, it is difficult to dispose the gasket in the opening of the outer cylinder, and thus the above-described plugging operation is performed with the gasket alone. For this reason, as a prefilled syringe, it is common to require a subsequent plunger mounting operation. In order to make it easy to install the plunger in the gasket, to prevent the occurrence of liquid leakage during the installation work, and to reduce the rise in internal pressure, the plunger has a male thread and the gasket has a female thread. It is common to have a mounting mechanism that is provided and screwed together.
However, the conventional coupling by screwing may be loosened due to a difference in the size of screws at the time of manufacture or an error in tightening torque of the assembly machine. In this case, the plunger may rotate due to vibration or the like applied during transportation, and fall off from the gasket.
Japanese Unexamined Patent Publication No. 2007-111547 (Patent Document 1) has been proposed as a plunger that can prevent such separation from the gasket. The plunger of Patent Document 1 includes a plunger rod 20 having a top surface 22 provided with a male screw 21, and a gasket 10 provided with a female screw 11 screwed into the male screw 21. The surface 22 is provided with a convex portion 23 protruding in the distal direction, and the gasket 10 is provided with a concave portion 12 that engages with the convex portion 23.

JP 2007-111547 A

In the thing of the said patent document 1, it has a sufficient function as a locking prevention. However, when the plunger is mounted on the gasket, the convex portion 23 provided on the top surface 22 of the plunger rod 20 may come into pressure contact with the vicinity of the concave portion 12 of the gasket 10 and the gasket may be rotated by the pressure contact. The rotation of the gasket may cause liquid leakage in the prefilled syringe. Further, the press contact between the convex portion 23 provided on the top surface 22 of the plunger rod 20 and the vicinity of the concave portion 12 of the gasket 10 causes a high mounting resistance.
An object of the present invention is to reduce the mounting resistance when the plunger body is screwed to the gasket, to facilitate the mounting operation, and to prevent the rotation of the gasket during the mounting operation. Provided are a plunger for a syringe capable of preventing leakage, a syringe using the same, and a prefilled syringe.

What achieves the above object is as follows.
(1) A plunger for a syringe comprising a gasket having a front end closed and a rear end opened, and having a lumen therein, and a plunger main body attached to or attachable to the gasket,
The plunger main body includes a main body portion, a flat plate portion provided on the main body portion, a front end portion that protrudes forward from the flat plate portion and can be stored in the lumen portion of the gasket, and an outer surface of the front end portion A plunger-side threaded portion provided on the plate, and a rotation regulating rib provided on the flat plate portion and projecting in the distal direction.
The gasket is a cylindrical body whose front end is closed and whose rear end is open, and is provided on the inner surface of the lumen portion, and is a helical thread for screwing with the plunger side threaded portion of the plunger body. And a rib storage recess that is provided on the base end face and that can receive the rotation regulating rib of the plunger body,
Further, the gasket is a side portion of the rib housing recess, and a portion where the rotation restricting rib of the plunger main body is slidably contacted when the plunger main body is attached to the gasket is an easily deformable portion. The plunger for the syringe.

(2) The easily deformable portion includes one or a plurality of slits provided at positions serving as side portions of the rib housing recesses of the gasket, and the slits are provided at a peripheral edge of the bottom surface of the gasket. The plunger for a syringe according to (1), wherein the plunger extends from the inner cavity portion toward the outer surface of the gasket and does not reach the outer surface.
(3) The plunger for a syringe according to (2), wherein the easily deformable portion includes a circumferential notch that extends in a circumferential direction from a side surface of the rib housing recess and communicates with the slit.
(4) The easily deformable portion is provided at a portion where the rotation regulating rib of the plunger main body is slidably contacted with the plunger main body when the plunger main body is mounted on the gasket, and gradually moves toward the rib storing concave portion. A recess for guiding to be deepened, and a wall portion that can be climbed, which is located between the recess for guiding rib and the recess for guiding, and has an inclined surface inclined toward the recess for storing rib, the guide recess side The syringe plunger as described in (1) above, which is formed by:
(5) The rotation restricting rib is thinner toward the apex direction of the rotation restricting rib, and a surface in the rotation direction of the gasket when the plunger main body is attached to the gasket is the rotation. The plunger for a syringe according to any one of the above (1) or (4), which is an inclined surface inclined toward the apex of the regulating rib.
(6) Two or more rotation restricting ribs are provided so as to be equiangular with respect to the central axis of the plunger main body, and the rib storing recess corresponds to the rotation restricting rib. The syringe plunger according to any one of (1) to (5), wherein two or more are provided so as to be equiangular with respect to the central axis of the gasket.
(7) The plunger for a syringe according to any one of (1) to (6), wherein the plunger side screwing portion is a spiral rib.
(8) The syringe plunger according to any one of (1) to (7), wherein the plunger main body is attached to the gasket.
(9) A syringe comprising the syringe plunger according to any one of (1) to (8) above and an outer cylinder that slidably accommodates the gasket.
(10) The syringe plunger according to any one of (1) to (8) above, an outer cylinder that slidably accommodates the gasket, and a sealing member that seals a distal end opening of the outer cylinder And a prefilled syringe comprising a medicine stored in a medicine storage portion formed in the outer cylinder.

  The plunger for a syringe of the present invention includes a gasket having a front end closed and a rear end opened, and having a lumen therein, and a plunger main body attached to or attachable to the gasket. The plunger main body includes a main body portion, a flat plate portion provided on the main body portion, a front end portion that protrudes forward from the flat plate portion and can be stored in a lumen portion of the gasket, and a plunger provided on an outer surface of the front end portion. The gasket is a cylindrical body provided with a side screwing portion and a rotation restricting rib provided in the flat plate portion and projecting in the front end direction. The gasket is a cylindrical body with the front end closed and the rear end opened, and is provided on the inner surface of the lumen portion A helical threaded portion for screwing with the plunger-side threaded portion of the plunger main body, and a rib storage recess that is provided on the base end face and can accommodate the rotation regulating rib of the plunger main body. . The gasket is the side portion of the rib housing recess, and the portion with which the rotation regulating rib of the plunger body slides when the plunger body is mounted on the gasket is an easily deformable portion. For this reason, when the plunger main body is screwed to the gasket, the side portion of the rib housing recess that is likely to generate a high sliding contact resistance is an easily deformable portion. The mounting resistance at the time of joint mounting is small, the mounting work is easy, the gasket is prevented from rotating during the mounting work, and the liquid leakage due to the rotation of the gasket is prevented.

FIG. 1 is a front view of a plunger for a syringe according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a bottom view of the gasket used for the syringe plunger shown in FIG. 1. 4 is a longitudinal sectional view of the gasket shown in FIG. FIG. 4 is a front view of a plunger main body used for the syringe plunger shown in FIG. 1. FIG. 6 is an explanatory diagram for explaining a mounting body of a gasket and a plunger main body in the syringe plunger of the present invention. FIG. 7 is an enlarged front view of the distal end portion of the plunger main body shown in FIG. FIG. 8 is a bottom view of a gasket used for a syringe plunger according to another embodiment of the present invention. FIG. 9 is a cross-sectional view of the gasket shown in FIG. FIG. 10 is a longitudinal sectional view of the prefilled syringe according to the embodiment of the present invention. FIG. 11 is a longitudinal sectional view of a prefilled syringe according to another embodiment of the present invention. FIG. 12 is a front view of an outer cylinder used for the prefilled syringe of FIGS. 10 and 11. FIG. 13 is a longitudinal sectional view of a sealing member used in the prefilled syringe of FIGS. 10 and 11.

The syringe plunger of the present invention, the syringe using the plunger, and the prefilled syringe will be described with reference to the illustrated embodiments.
The plunger 1 for a syringe of the present invention includes a gasket 2 having a front end closed and a rear end opened, and having a lumen 21 therein, and a plunger main body 3 attached to or attachable to the gasket 2. The plunger main body 3 includes a main body portion 30, a flat plate portion 36 provided on the main body portion 30, a front end portion 31 that protrudes forward from the flat plate portion 36 and can be stored in the lumen portion 21 of the gasket 2, and a front end portion 31. The plunger side screwing part 32 provided in the outer surface of this part and the rib 35 for rotation control which is provided in the flat plate part 36 and protrudes in the front-end | tip direction are provided. The gasket 2 is a cylindrical body whose front end is closed and whose rear end is open. The gasket 2 is provided on the inner surface of the lumen portion 21 and is helically screwed to be engaged with the plunger-side screw portion 32 of the plunger body 3. And a rib housing recess 25 that is provided on the base end face and can accommodate the rotation regulating rib 35 of the plunger main body 3. Further, the gasket 2 is a side portion of the rib housing recess 25, and a portion with which the rotation restricting rib 35 of the plunger body 3 is slidably contacted with the easily deformable portion 26 when the plunger body 3 is attached to the gasket 2. It has become.
As shown in FIG. 1, the syringe plunger 1 includes a gasket 2 and a plunger body 3.

  As shown in FIGS. 1 to 4, the gasket 2 of this embodiment is a cylindrical body having a closed front end and a rear end opening. The gasket 2 has a main body portion 20 and a tapered portion 22 that is provided on the distal end side of the main body portion 20 and decreases in a tapered shape toward the distal end side. Further, the gasket 2 includes a front end side sliding contact portion 23a that is provided in the front end side portion and that is in sliding contact with the inner surface of the outer cylinder, and a rear end side sliding contact portion 23b that is provided in the rear end side portion. Moreover, it is preferable that the tip side sliding contact portion 23a has a large diameter near the center in the axial direction. Specifically, it is preferable that the tip side sliding contact portion 23a is formed in a somewhat drum drum shape. With such a configuration, the tip side sliding contact portion 23a is unlikely to be separated from the inner surface of the outer cylinder when the plunger is pressed, so that the chemical liquid is less likely to leak. Moreover, as shown in FIG. 1 and FIG. 4, it is preferable that the front end side sliding contact portion 23a is formed wide in the axial direction.

The gasket 2 is a cylindrical body whose front end is closed and whose rear end is open. The gasket 2 is provided on the inner surface of the lumen 21 and has a spiral shape for screwing with the plunger-side threaded portion 32 of the plunger body 3. A rib housing recess 25 that is provided on the screw engagement portion 24 and on the base end face and can accommodate the rotation restricting rib 35 of the plunger body 3, a side portion of the rib housing recess 25, and the gasket 2 And an easily deformable portion 26 formed at a portion where the rotation restricting rib 35 of the plunger main body 3 is slidably contacted when the plunger main body 3 is mounted.
And in the gasket 3 of this Example, the helical threading part 24 is formed in the inner surface of the inner cavity part 21 of the part which becomes a front end side from the recessed part 25 for rib accommodation mentioned above.
The helical screw portion 24 is formed by one or a plurality of screw threads, and the plunger side screw portion 32 of the plunger main body 3 advances through a helical space 29 formed by the screw threads. In addition, the spiral threaded portion 24 is not formed on the inner surface of the lumen portion 21 where the rib storage recess 25 is formed. Further, in this embodiment, the helical threaded portion 24 becomes two (two) helically threaded portions 24 so as to correspond to a plunger side threaded portion 32 of the plunger body 3 described later. Yes. In addition, although it is preferable to provide a plurality (specifically, two strips) of helical screw portions as described above, the spiral screw portion (spiral protrusion) may be only one (one). Good.
In the gasket 2 of this embodiment, the inner surface of the distal end portion of the lumen 21 of the gasket 2 is reduced in diameter toward the distal end of the gasket 2. And the protrusion part is provided in the center part of the front end inner surface.

  The gasket 3 has a lumen 21. Further, on the inner surface of the lumen portion 21, a helical screw portion 24 for screwing with the plunger side screw portion 32 of the plunger body 3, a rear end side from the helical screw portion 24, and a gasket 3 is provided with a rib storage recess 25 formed on the rear end face of the head. Further, when the gasket 3 is viewed from the bottom, an easily deformable portion 26 is formed on a side portion (specifically, a left side portion of the rib storage recess 25) that is counterclockwise of the rib storage recess 25. The portion where the easily deformable portion 26 is formed is a portion where the rotation restricting rib 35 of the plunger body 3 is in sliding contact (pressure contact) when the plunger body 3 is attached to the gasket 2, and passes through this portion. As a result, the rotation restricting rib 35 of the plunger body 3 is accommodated in the rib accommodating recess 25.

  In the gasket 2 of this embodiment, the rib housing recess 25 is formed on the bottom surface of the gasket 2 and has a starting end at a position slightly closer to the center than the outer peripheral surface, and reaches the lumen 21. It has become. In other words, the rib housing recess 25 does not reach the side surface of the gasket 2. For this reason, the gasket 2 has a recessed part non-formation part between the recessed part 25 for rib accommodation, and the outer peripheral surface of a gasket. Two or more rotation restricting ribs 35 of the plunger main body 3 to be described later are provided so as to be at an equal angle with respect to the central axis of the plunger main body 3, and the rib housing recess 25 of the gasket 2 is also used for rotation restriction. Two or more are provided so as to correspond to the ribs 35 so as to be equiangular with respect to the central axis of the gasket 2. Further, it is preferable to provide two or more, particularly 2 to 6, rib storage recesses 25 so as to be equiangular with respect to the central axis of the gasket 2. Further, in the gasket 2 of this embodiment, as shown in FIG. 3, the two edges 25a and 25b on the lumen 21 side of the rib housing recess 25 are rounded (chamfered). ing. Further, the side surface of the rib housing recess 25 on the easily deformable portion 26 side is an upright surface, and abuts on a side surface of a rotation regulating rib 35 described later.

In the gasket 2 of this embodiment, the easily deformable portion 26 is a side portion of the rib housing recess 25 of the gasket 2 (specifically, the left side of the rib housing recess 25, the mounting of the plunger body 3 on the gasket 2). Sometimes, one or a plurality of slits 27 are provided at positions where the rotation restricting ribs 35 of the plunger main body 3 come into sliding contact). The slit 27 is provided at the peripheral edge of the bottom surface of the gasket 2, extends from the inner cavity portion 21 toward the outer surface of the gasket 2, and does not reach the outer surface.
Specifically, as shown in FIG. 3 and FIG. 4, the easily deformable portion 26 is provided at a position to be the side portion of the rib storage recess 25 of the gasket 2 (the left side portion of the rib storage recess 25). It is formed by the slit 27. By providing this slit 27, the easily deformable portion 26 can be easily deformed (in other words, tilted) toward the rib housing recess 25, and the bottom peripheral edge of the gasket 2 when the plunger body 3 is attached to the gasket 2. In the case of a prefilled syringe in which the gasket is preliminarily stored in the outer cylinder, the sliding contact resistance between the portion and the rotation regulating rib 35 of the plunger body 3 is reduced, and the mounting becomes easy. Prevent gasket rotation.

The slit 27 is formed in the bottom surface portion of the gasket 2, has a starting end at a position slightly closer to the center than the outer peripheral surface, extends in the central direction of the lumen portion, and reaches the lumen portion 21. Yes. In other words, the slit 27 does not reach the side surface of the gasket 2.
Furthermore, in the gasket 2 of this embodiment, the side portion that is counterclockwise of the rib storage recess 25 (specifically, the left side of the rib storage recess 25, when the plunger body 3 is attached to the gasket 2, A plurality of slits 27 are formed in a portion of the plunger body 3 where the rotation restricting rib 35 is in sliding contact. For this reason, the side part (the left side part, the side part opposite to the rib storage recessed part 25) of the easily deformable part 26 formed on the side part of the rib storing recessed part 25 is the second easily deformable part, A side portion (left side portion, side portion opposite to the easily deformable portion 26) of the second easily deformable portion is a third easily deformable portion. Thus, by providing a plurality of easily deformable portions, the sliding contact resistance between the bottom peripheral edge portion of the gasket 2 and the rotation restricting rib 35 of the plunger main body 3 when the plunger main body 3 is attached to the gasket 2 is further improved. Less. The depth of the slit 27 is preferably substantially the same as the depth of the rib housing recess 25, but may be slightly deeper or slightly shallower.

Furthermore, in the gasket 2 of this embodiment, as shown in FIG. 3, the easily deformable portion 26 is provided on the side surface of the rib storage recess 25 (specifically, the left side of the rib storage recess 25, the plan for the gasket 2). When the jar body 3 is mounted, a circumferential cut 28 is provided that extends in the circumferential direction from the side of the plunger body 3 on the side where the rotation regulating rib 35 is in sliding contact, and communicates with the slit 27. In this embodiment, the circumferential cut 28 has a short arc shape. The cuts 28 extend in the counterclockwise direction from the left side surface of the rib housing recess 25 so as to reach all the slits 27. By providing such a circumferential cut 28, the deformation resistance of the easily deformable portion 26 is reduced, and the bottom peripheral edge of the gasket 2 and the rotation of the plunger main body 3 when the plunger main body 3 is attached to the gasket 2. The sliding contact resistance of the regulating rib 35 is also reduced. The depth of the circumferential cut 28 is preferably substantially the same as the depth of the slit 27, but may be slightly deeper or slightly shallower.
As described above, in the gasket 2 of this embodiment, a plurality of rib storage recesses 25 are provided, and all of the side portions (specifically, the left side surface of the rib storage recess 25, to the gasket 2). The above-described easily deformable portion 26 is formed on the side of the plunger main body 3 on the side where the rotation restricting ribs 35 are in sliding contact with the plunger main body 3.

In the present invention, the easily deformable portion means that a part of the gasket is physically easily deformed to reduce the sliding resistance of the rotation restriction rib of the plunger body, in other words, the rotation restriction rib. This means a portion configured to reduce the stress when a pressing force is applied by sliding contact. As described above, the easily deformable portion is preferably formed by a slit, but may be formed by a concave portion as in the gasket 2a shown in FIGS.
In the gasket 2a of this embodiment, the easily deformable portion is provided in a portion where the rotation restricting rib 35 of the plunger main body 3 is slidably contacted with the gasket 2a when the plunger main body 3 is attached to the gasket 2a. It is possible to ride on a guiding recess 61 that gradually becomes deeper, and between the rib storing recess 25 and the guiding recess 61, and the guiding recess side is an inclined surface 61b inclined toward the rib storing recess. And the wall portion 62 is formed. This wall portion 62 is an easily deformable portion.
In the gasket 2a of this embodiment, the easily deformable portion is the side portion of the rib storage recess 25 of the gasket 2a (specifically, the left side of the rib storage recess 25, when the plunger body 3 is attached to the gasket 2a). The wall portion 62 provided at a position where the rotation restricting rib 35 of the plunger main body 3 is in sliding contact) and the side portion (the left side portion, the side portion opposite to the easily deformable portion 26). The guide recess 61 is configured. The guiding recessed portion 61 has a first inclined surface 61 a that is inclined so that the recessed portion 61 becomes deeper toward the wall portion 62. For this reason, when the plunger main body 3 is mounted on the gasket 2a, the peripheral edge portion of the bottom surface of the gasket 2a and the rotation regulating rib 35 of the plunger main body 3 are less likely to be in sliding contact with each other, and the sliding contact resistance is reduced. The rotation restricting rib 35 can be brought into contact with the second inclined surface 61 b (that is, the wall portion 62) of the guiding recess 61. Further, since the second inclined surface 61b is inclined toward the rib housing recess 25 side, the passage of the wall portion 62 of the rotation restricting rib 35, in other words, the deformation of the wall portion 62 is facilitated. .

The gaskets 2 and 2a preferably have a main body portion 60 having a diameter of 5 to 30 mm, a total length of 5 to 30 mm, and a taper angle of 1 to 5 degrees with respect to the inclination of the taper portion 22.
As a constituent material of the gaskets 2 and 2a, known materials conventionally used for syringe gaskets can be used. Examples thereof include rubber, elastomer, polyolefin resin, fluorine resin, and polyester resin. As the rubber, for example, natural rubber, isoprene rubber, butyl rubber, chloroprene rubber, nitrile-butadiene rubber, styrene-butadiene rubber, and silicone rubber are preferable, and vulcanized rubber is particularly preferable. As the elastomer, for example, a polyvinyl chloride elastomer, a polyolefin elastomer, a styrene elastomer, a polyester elastomer, a polyamide elastomer, a polyurethane elastomer, and a mixture thereof are preferable. Among the above rubbers and elastomers, styrene-butadiene rubber, butyl rubber, and styrene elastomers have suitable hardness and elastic properties, and various sterilization methods such as γ-ray sterilization, electron beam sterilization, and high-pressure steam sterilization can be adopted. Therefore, it is preferable.
Further, the tip portion of the syringe gasket may be coated with a low drug-adsorbing substance or the like.

As a material for the low drug adsorbing layer, a known material conventionally used for a laminated gasket for syringes can be used. Examples of the material for the low drug adsorption layer include polyolefin resins, fluorine resins, and polyester resins. Specifically, the polyolefin resin is preferably polypropylene, ultrahigh molecular weight polyethylene, poly (4-methylpentene-1), cyclic polyolefin or the like, and the fluorine resin is tetrafluoroethylene-perfluoroethoxyethylene copolymer. Polymers, polytetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymers, tetrafluoroethylene / hexafluoropropylene copolymers and the like are preferable.
Moreover, you may coat | cover a lubricant etc. on the surface of both or at least one of the front end side sliding contact part 23a of the gasket 2, and the rear end side sliding contact part 23b. Silicone oil is suitable as the lubricant.

As shown in FIGS. 1, 2, 5, and 6, the plunger main body 3 includes a main body portion 30 having a flat plate portion 36 capable of pressing the base end surface of the gasket 2 on the distal end side, and a front side from the main body portion 30. And a distal end portion 31 that can be accommodated in the lumen portion 21 of the gasket 2.
The main body 30 includes a shaft portion 37 formed in a cross shape in cross section, and a flat plate portion 36 is provided at the tip thereof. A plunger pressing portion 39 is provided at the proximal end of the shaft portion 37.
The tip portion 31 is a cylindrical portion that protrudes in the tip direction from the flat plate portion 36, and includes a plunger-side screw portion that can be screwed with the helical screw portion 24 of the gasket 2. Further, the flat plate portion 36 includes a rotation restricting rib 35 that protrudes in the front end direction from the front end side surface of the flat plate portion 36.

In the prefilled syringe 1 of this embodiment, the plunger side screwing portion of the plunger 4 is constituted by a helical rib 32. The plunger side screwing portion is preferably a helical rib, but may be any one that can be screwed with the helical screwing portion of the gasket described above, for example, a lug (configured by a plurality of protrusions). It may be. Examples of the lug include those in which partial protrusions are formed on the same circumferential portion of the outer surface of the distal end portion 31 of the plunger. For example, a plurality of, for example, two, two facing each other can be considered on the outer periphery of the distal end portion of the distal end portion 31 of the plunger.
In this embodiment, the plunger-side threaded portion is a spiral rib 32, and the spiral rib 32 is formed on the outer surface of the distal end portion of the cylindrical portion that forms the mounting distal end portion 31. In addition, the plunger main body 3 includes two (two) helical ribs so as to correspond to the above-described helical screwing portion 24 of the gasket 2. Although it is preferable to provide such a plurality (specifically, two strips) of spiral ribs, the spiral rib may be only one strip (one).
The rotation regulating rib 35 has a size and a shape in which the end portion on the peripheral side of the flat plate portion 36 can be accommodated in the rib accommodating recess 25 of the gasket 2 described above. In this embodiment, as shown in FIG. 6, the rotation restricting rib 35 is provided on the upper surface of the flat plate portion 36, and has a start end at a position slightly closer to the center than the outer peripheral edge of the flat plate portion 36. It extends in the central direction of the portion 31.
Further, two or more rotation restricting ribs 35 are provided so as to be equiangular with respect to the central axis of the plunger body 3 (the central axis of the cylindrical tip 31). Further, as described above, two or more rib housing recesses 25 are provided so as to be equiangular with the central axis of the gasket 2 so as to correspond to the rotation restricting ribs 35. In particular, 2 to 6 are preferably provided. As shown in FIG. 6, in the state where the plunger body 3 is mounted on the gasket 2, the side surface of the rotation regulating rib 35 that contacts the side surface on the easily deformable portion 26 side of the rib housing recess 25 of the gasket 2 is , Has become a standing surface. Thereby, after rotation, when rotation to the direction which detaches | leaves from the gasket 2 is provided to the plunger main body 3, both contact | abut reliably and detachment | leave is suppressed. Further, the easily deformable portion 26 of the gasket 2 described above is easily deformed in the direction of the rib housing recess 25, but is difficult to deform in the opposite direction.

Further, like the plunger main body 3 a of the embodiment shown in FIG. 7, the rotation restricting rib 35 becomes thinner toward the apex direction of the rotation restricting rib 35 and the plunger main body 3 is attached to the gasket 2. The surface in the rotational direction of the gasket 2 at that time may be an inclined surface 35 a that is inclined toward the apex of the rotation restricting rib 35. By doing so, the sliding contact resistance between the peripheral edge of the bottom surface of the gasket 2 and the rotation restricting rib 35 of the plunger main body 3 when the plunger main body 3 is mounted on the gasket 2 is reduced.
As a constituent material of the plunger main bodies 3 and 3a, it is preferable to use a hard or semi-hard resin such as high-density polyethylene, polypropylene, polystyrene, or polyethylene terephthalate.
As shown in FIGS. 1 and 2, the plunger for a syringe according to the present invention is not limited to the one in which the plunger main body 3 is mounted on the gasket 2, and the plunger main body is attached to the gasket at the time of use. It may be of the type that wears.

Next, the syringe and prefilled syringe of the present invention will be described using examples.
The syringe of the present invention includes the syringe plunger 1 and the outer cylinder 4 that slidably accommodates the gasket 2.
The prefilled syringe of the present invention includes the above-described syringe plunger 1, an outer cylinder 4 that slidably accommodates the gasket 2, a sealing member 5 that seals the distal end opening of the outer cylinder 4, It consists of a medicine 8 stored in a medicine storage part formed in the cylinder 4.
Specifically, the prefilled syringe 10 of the present invention includes a prefilled syringe body 20 and a plunger body 3 that can be attached to or attached to the gasket 2 of the prefilled syringe body 20.
In addition, in the prefilled syringe 10 shown in FIG. 10, the plunger main body 3 is not attached to the gasket 2 of the prefilled syringe main body 20, but is attached at the time of use. Moreover, in the prefilled syringe 10a shown in FIG. 11, the plunger main body 3 is attached to the gasket 2 of the prefilled syringe main body 20. The difference between the two is only the difference in whether or not the plunger body 3 is attached to the gasket.
And the above-mentioned plunger 1 for syringes is used for said prefilled syringes 10 and 10a. As the syringe plunger 1 and the gasket and plunger main body constituting it, all of those described above can be used.
The prefilled syringe body 10 a is formed in the outer cylinder 4, the gasket 2 slidably accommodated in the outer cylinder 4, the sealing member 5 that seals the distal end opening of the outer cylinder 4, and the outer cylinder 4. And the medicine 8 stored in the medicine storage section.

The outer cylinder 4 is a cylindrical body made of a transparent or translucent material, preferably a material having low oxygen permeability and water vapor permeability.
As shown in FIGS. 10, 11, and 12, the outer cylinder 4 includes a nozzle portion 42 and a collar 43.
The nozzle portion 42 is provided at the distal end of the outer cylinder 4 and includes a distal end opening for discharging a chemical solution or the like in the outer cylinder, and is formed so as to be tapered toward the distal end. The collar 43 is formed in a cylindrical shape concentrically with the nozzle portion 42 so as to surround the nozzle portion 42. The collar 43 is open at the distal end, and the inner diameter and outer diameter of the collar 43 are substantially the same from the proximal end to the distal end. Further, the tip of the nozzle portion 42 protrudes from the tip opening of the collar 43, and the nozzle portion 42 and the tip of the collar 43 accommodate the nozzle portion 42 and the collar 43 in the sealing member (seal cap) 5. It is chamfered to make it easier.
On the inner peripheral surface of the collar, a screw groove (external cylinder side screwing) for screwing with a screw thread (cap side screwing part) 54 formed in a nozzle housing part 53 of a sealing member (seal cap) 5 described later. Part) 45 is formed. Thereby, the outer cylinder 4 and the seal cap 5 are screwed between the inner peripheral surface of the collar and the outer peripheral surface of the nozzle storage portion. Further, the thread groove (outer tube side screwing portion) 45 is a portion to which the injection needle (the hub of the injection needle) is attached after the seal cap 5 is removed from the outer tube.

As shown in FIGS. 10, 11, and 12, the outer cylinder has a flange 44. The flange 44 is an elliptical donut-shaped disk portion formed so as to protrude in the vertical direction from the entire rear end circumference of the outer cylinder 4. As shown in FIGS. 10, 11 and 13, the flange 44 includes two gripping portions which are wide and face each other, and a plurality of ribs are formed on the front end surface side of the gripping portion.
Examples of the material for forming the outer cylinder 4 include polypropylene, polyethylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly- (4-methylpentene-1), acrylic resin, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate. Various resins such as polyester and cyclic polyolefin can be used, and among them, resins such as polypropylene and cyclic polyolefin are preferable because they are easy to mold and have heat resistance.

As shown in FIGS. 10, 11, and 13, the seal cap 5 that is a sealing member includes a closed end 51, a nozzle storage portion 53, and a color storage portion 52.
The nozzle storage portion 53 is provided in the center portion of the seal cap 5 and has a cylindrical shape with a closed end. The inner diameter of the nozzle storage portion 53 is made slightly larger than the nozzle portion 42 and is slightly tapered from the distal end to the proximal end toward the proximal end so that the entire nozzle portion is accommodated from the proximal opening. ing.
A seal member 55 for liquid-tightly sealing the distal end opening of the outer cylinder 4 is accommodated in the inner closed surface (the inner surface of the closed end 51) of the nozzle storage portion 53. The seal member 55 is preferably an elastic member so that the tip opening of the outer cylinder 4 can be sealed in a liquid-tight manner. As a material for forming the sealing member, it is preferable to use, for example, natural rubber, isoprene rubber, butadiene rubber, fluororubber, silicone rubber or other synthetic rubber, or thermoplastic elastomer such as olefin elastomer or styrene elastomer.
Further, on the outer surface of the nozzle storage portion 53, a screw thread (cap-side screwing portion) 54 for screwing with a screw groove (outer tube-side screwing portion) 45 formed on the inner surface of the collar 43 of the outer tube 4. Is formed. Thereby, the outer cylinder 4 and the seal cap 5 are screwed between the outer surface of the nozzle housing portion and the inner surface of the collar.

The color storage portion 52 is a cylindrical body that is formed so as to surround the nozzle storage portion 53 and has a closed end, and stores the collar 43 between the inner surface of the color storage portion and the outer surface of the nozzle storage portion. Further, the color storage portion 52 formed in a cylindrical shape is concentric with the nozzle storage portion 53, and the inner diameter of the color storage portion 52 is substantially the same from the front end to the base end.
In addition, as shown in FIG. 13, the outer surface of the seal cap 5 (the outer peripheral surface of the color storage portion 52) is cut in the vertical direction so that fingers do not slip when the seal cap is rotated. ing.
Examples of the material for forming the seal cap include polypropylene, polyethylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly- (4-methylpentene-1), acrylic resin, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, and the like. Among these, various resins such as polyester and cyclic polyolefin are preferable. Among them, resins such as polypropylene and cyclic polyolefin are preferable because they are easy to mold and have heat resistance.

And in the prefilled syringe 1 of this invention, as shown in FIG.10 and FIG.11, the chemical | medical agent storage part formed in the outer cylinder is filled with the chemical | medical agent 8. As shown in FIG.
As the drug 8, any drug may be used. For example, cyclosporine, benzodiazepine drugs, sodium chloride injection, vitamins, minerals, and the like, powders such as antibiotics and protein preparations, or freeze-dried Drugs or liquids are used. The prefilled syringe of the present invention is particularly suitable for a prefilled syringe of the type that is administered using a syringe pump. Therefore, the medicine to be filled is preferably a medicine suitable for using such administration means, and nitro Examples include glycerin injection, isosorbide nitrate injection, dopamine hydrochloride (dopamine hydrochloride) injection, dobutamine hydrochloride injection, morphine hydrochloride injection, and the like.

Next, the effect | action of the prefilled syringe 1 of this invention is demonstrated using FIG. 10, FIG.
The prefilled syringe body 20 is in a state in which the gasket 2 is housed in the proximal end portion of the outer cylinder 4. The plunger main body 3 is entered from the distal end portion 31 while being rotated into the gasket 2. Thereby, the helical screw part 24 of the gasket 2 and the helical rib 32 of the front-end | tip part 31 of the plunger main body 3 are screwed together. As the screwing progresses, the rotation restricting rib 35 of the flat plate portion 36 of the plunger main body 3 comes into contact with the peripheral edge of the bottom surface of the gasket 2, and when the screwing further advances, the easily deformable portion 26 of the gasket 2 slides. After touching and deforming so that the easily deformable portion 26 is pushed down, the end portion of the rotation restricting rib 35 of the flat plate portion 36 of the plunger body 3 is located in the rib accommodating recess 25 of the gasket 2 as shown in FIG. The mounting operation of the plunger body 3 to the gasket 2 is completed.

DESCRIPTION OF SYMBOLS 1 Plunger 2 for syringes, 2a Gasket 3 Plunger main body 4 Outer cylinder 5 Sealing member 8 Chemical | medical agent 25 Rib accommodation recessed part 26 Easily-deformable part 27 Slit 28 Circumferential notch 10, 10a Prefilled syringe

Claims (10)

A plunger for a syringe comprising a gasket having a front end closed and a rear end opened, and having a lumen therein, and a plunger body attached to or attachable to the gasket,
The plunger main body includes a main body portion, a flat plate portion provided on the main body portion, a front end portion that protrudes forward from the flat plate portion and can be stored in the lumen portion of the gasket, and an outer surface of the front end portion A plunger-side threaded portion provided on the plate, and a rotation regulating rib provided on the flat plate portion and projecting in the distal direction.
The gasket is a cylindrical body whose front end is closed and whose rear end is open, and is provided on the inner surface of the lumen portion, and is a helical thread for screwing with the plunger side threaded portion of the plunger body. And a rib storage recess that is provided on the base end face and that can receive the rotation regulating rib of the plunger body,
Further, the gasket is a side portion of the rib housing recess, and a portion where the rotation restricting rib of the plunger main body is slidably contacted when the plunger main body is attached to the gasket is an easily deformable portion. A plunger for a syringe. The easily deformable portion includes one or a plurality of slits provided at positions to be the side portions of the rib storage recesses of the gasket, and the slits are provided at a peripheral edge of the bottom surface of the gasket, and the lumen The plunger for a syringe according to claim 1, wherein the plunger extends from the portion toward the outer surface of the gasket and does not reach the outer surface. The plunger for a syringe according to claim 2, wherein the easily deformable portion includes a circumferential cut extending in a circumferential direction from a side surface of the rib housing recess and communicating with the slit. The easily deformable portion is provided at a portion where the rotation restricting rib of the plunger main body is slidably contacted with the plunger main body when the plunger main body is mounted on the gasket, and is gradually deepened toward the rib storing concave portion. And a climbable wall portion that is positioned between the rib storage recess and the guide recess and has an inclined surface inclined toward the rib storage recess. The syringe plunger according to claim 1. The rotation restricting rib is thinner toward the apex direction of the rotation restricting rib, and a surface in the rotation direction of the gasket when the plunger body is attached to the gasket is the rotation restricting rib. The plunger for a syringe according to any one of claims 1 and 4, wherein the plunger is an inclined surface inclined toward the top of the syringe. Two or more rotation restricting ribs are provided so as to be equiangular with respect to the central axis of the plunger body, and the gasket for accommodating the rib accommodating recess also corresponds to the rotation restricting rib. The plunger for a syringe according to any one of claims 1 to 5, wherein two or more are provided so as to be equiangular with respect to the central axis. The plunger for a syringe according to any one of claims 1 to 6, wherein the plunger side screwing portion is a helical rib. The syringe plunger according to any one of claims 1 to 7, wherein the plunger main body is attached to the gasket. A syringe, comprising: the plunger for a syringe according to any one of claims 1 to 8; and an outer cylinder that slidably accommodates the gasket. The plunger for a syringe according to any one of claims 1 to 8, an outer cylinder that slidably accommodates the gasket, a sealing member that seals a distal end opening of the outer cylinder, and the outer cylinder The prefilled syringe which consists of a chemical | medical agent accommodated in the chemical | medical agent storage part formed in the inside.

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