WO2022190982A1

WO2022190982A1 - Pre-filled syringe

Info

Publication number: WO2022190982A1
Application number: PCT/JP2022/008821
Authority: WO
Inventors: 沖原等
Original assignee: テルモ株式会社
Priority date: 2021-03-08
Filing date: 2022-03-02
Publication date: 2022-09-15

Abstract

A pre-filled syringe (10) has a bypass structure (48) which has a plurality of groove parts (50) that form void spaces between an outer periphery of an intermediate gasket (36) and an inner peripheral surface (12a) of a syringe barrel (12) so as to communicate a first medicine chamber (40) and a second medicine chamber (42) with each other, in which each of the groove parts (50) has a blockage-prevented structure such that each of the groove parts (50) cannot be completely blocked with the compressed intermediate gasket (36).

Description

prefilled syringe

The present invention relates to prefilled syringes.

A pre-filled syringe with two chambers is one of the mixing devices that mix two types of drugs immediately before use. In this prefilled syringe, for example, as shown in Japanese Unexamined Patent Application Publication No. 2013-75154, the storage space inside the syringe outer cylinder is separated into two chambers by an intermediate gasket, and different types of drugs are stored in each chamber. is enclosed. Near the center of the syringe outer cylinder, a bypass channel is formed so as to protrude radially outward. It is possible to mix the chemicals enclosed in the In addition, the above-mentioned prefilled syringe also has an administration function as a syringe and can be used as it is after mixing, making it a convenient and highly safe mixing device.

However, conventional prefilled syringes have a bypass flow path provided at one location in the circumferential direction, which poses a problem of poor mixing performance when mixing chemicals in a narrow space inside the syringe. For example, when one chamber contains a powder and the other chamber contains a liquid (for example, water for dilution), the liquid flows from only one point in the circumferential direction. Depending on the properties of the ingredients, it may take time to mix.

In order to improve such poor mixability, it is conceivable to provide a plurality of grooves extending in the axial direction at multiple locations in the circumferential direction of the syringe as a bypass structure, allowing the liquid agent to pass through from multiple locations in the circumferential direction.

However, in the case of a bypass channel consisting of a plurality of grooves, there is a risk that the rubber material of the intermediate gasket will enter the grooves. In this case, the flow rate of the liquid agent decreases, the intermediate gasket passes through the bypass channel before the transfer of the liquid agent is completed, and part of the liquid agent remains without being transferred to the powder side. occurs.

Therefore, an object of one embodiment is to provide a prefilled syringe having a bypass structure that is excellent in mixability and liquid agent transferability.

One aspect of the following disclosure is a syringe outer cylinder having a housing space for containing a drug formed therein and having a nozzle at the tip, and the housing space of the syringe outer cylinder having two chambers, a first chamber and a second chamber. an intermediate gasket that separates the chamber, a proximal gasket disposed on the proximal side of the intermediate gasket, and an inner peripheral surface of the syringe outer cylinder, provided at an intermediate position spaced from the nozzle on the proximal side, a bypass structure that forms a gap with the outer peripheral portion of the intermediate gasket to communicate the first chamber and the second chamber, wherein the bypass structure is the inner peripheral surface of the syringe outer cylinder. and has a plurality of grooves extending in the axial direction and arranged at intervals in the circumferential direction, the grooves being prevented from being completely blocked by the compressed intermediate gasket. in a prefilled syringe with

Another aspect is a syringe outer cylinder having a housing space for containing a medicine formed therein and having a nozzle at the tip, and the housing space of the syringe outer cylinder being divided into two chambers, a first chamber and a second chamber. an intermediate gasket that separates; a proximal gasket that is arranged on the proximal side of the intermediate gasket; a bypass structure that forms a gap between the outer peripheral portion of the gasket and the first chamber and the second chamber for communication, wherein the bypass structure is axially attached to the inner peripheral surface of the syringe outer cylinder. a plurality of grooves extending in the direction of the syringe and arranged at intervals in the circumferential direction; and a pre-filled syringe having an annular recess.

According to the prefilled syringe of the above viewpoint, it is possible to improve the mixability of the liquid agent and the powder agent and the transferability of the liquid agent.

1 is a perspective view of a prefilled syringe according to a first embodiment; FIG. FIG. 2 is a cross-sectional view of the prefilled syringe of FIG. 1 cut along the axial direction; 3 is an enlarged perspective view of the bypass structure of FIG. 2; FIG. FIG. 4 is a cross-sectional view of the groove along a plane perpendicular to the axial direction of the syringe barrel of FIG. 3; It is explanatory drawing which shows the manufacturing method of the prefilled syringe which concerns on 1st Embodiment. 6A is an enlarged cross-sectional view of the contact portion between the groove portion and the intermediate gasket according to the comparative example, and FIG. 6B is an enlarged cross-sectional view of the contact portion between the groove portion and the intermediate gasket in FIG. 7A is a cross-sectional view of a groove according to Modification 1 of the first embodiment, and FIG. 7B is an enlarged cross-sectional view of a contact portion between the groove and an intermediate gasket in FIG. 7A. 8A is a cross-sectional view of a groove according to Modification 2 of the first embodiment, and FIG. 8B is an enlarged cross-sectional view of a contact portion between the groove and an intermediate gasket in FIG. 8A. It is a partial expansion perspective view of the bypass structure which concerns on 2nd Embodiment. FIG. 10 is a cross-sectional view showing the operation of the bypass structure of FIG. 9;

Preferred embodiments of prefilled syringes will be described below in detail with reference to the accompanying drawings.

(First embodiment)
The prefilled syringe 10 according to the present embodiment shown in FIG. and a pusher 18 for pushing out the intermediate gasket 36 and the base end gasket 38 in the syringe barrel 12 toward the nozzle 14 side.

The syringe outer cylinder 12 has a substantially cylindrical shape, and has a body portion 22 formed with a base end side opening 20 and a nozzle 14 provided at the tip of the body portion 22 on the base end side. As shown in FIG. 2, a lock adapter 24 is provided outside the nozzle 14 . A flange 26 projecting radially outward is formed at the proximal end of the body portion 22 . In the syringe barrel 12, the barrel 22, nozzle 14, lock adapter 24 and flange 26 are integrally formed. A grip 28 is detachably attached to the flange 26 .

A cap 16 is attached to the nozzle 14 . The cap 16 has a screw mechanism 30 that can be screwed onto the lock adapter 24 and a plug 32 that closes the nozzle 14 . When the cap 16 is removed, the pusher 18 can be moved forward. The cap 16 is removed from the lock adapter 24 just before use, and a needle unit (not shown) is attached to the lock adapter 24 for use.

Inside the syringe outer cylinder 12, an accommodation space 34 surrounded by the inner peripheral surface 12a and having a circular cross section is formed penetrating in the axial direction. The distal end of the accommodation space 34 communicates with the nozzle 14 , and the proximal end of the accommodation space 34 opens at the proximal opening 20 .

An intermediate gasket 36 and a proximal gasket 38 are inserted into the accommodation space 34 via the proximal side opening 20 . The intermediate gasket 36 and the base end gasket 38 are made of an elastic material such as rubber. The intermediate gasket 36 and the base end gasket 38 are slidably arranged in the syringe outer cylinder 12 while their outer peripheral portions are in liquid-tight contact with the inner peripheral surface 12a of the syringe outer cylinder 12 .

The intermediate gasket 36 is arranged near the center of the housing space 34, and divides the housing space 34 into a first chamber 40 on the proximal side and a second chamber 42 on the distal side. The second chamber 42 is closed by the cap 16 on the distal side and by the intermediate gasket 36 on the proximal side. The first chamber 40 is sealed by an intermediate gasket 36 on the distal side and by a proximal gasket 38 on the proximal side.

The liquid medicine B is enclosed in the first chamber 40, and the medicine A is enclosed in the second chamber 42. Drug A is liquid, gel or powder. The liquid agent B is liquid, and is, for example, diluent water for diluting the agent A or the like. As will be described later, the liquid medicine B is mixed with the medicine A just before use. In order to liquid-tightly separate the first chamber 40 and the second chamber 42 until the intermediate gasket 36 is used, the intermediate gasket 36 is arranged on the base end side of a bypass structure 48 (to be described later) in the initial position.

As shown in FIG. 3 , the accommodation space 34 of the present embodiment includes a first inner diameter portion 44 formed on the distal end side, a second inner diameter portion 46 formed on the proximal end side, the first inner diameter portion 44 and the second inner diameter portion 46 . 2 and a bypass structure 48 provided between the inner diameter portion 46 .

As shown in FIG. 3, the first inner diameter portion 44 is a portion having a circular inner peripheral surface 44a formed on the first inner diameter. The inner peripheral surface 44a is formed of a smooth surface, and has an inner diameter that allows the intermediate gasket 36 and the base end gasket 38 (see FIG. 2) to be in liquid-tight contact and slide in the axial direction.

The second inner diameter portion 46 is formed on the base end side of the first inner diameter portion 44 with the bypass structure 48 interposed therebetween. The second inner diameter portion 46 is a portion having a circular inner peripheral surface 46a formed with a second inner diameter larger than the first inner diameter. The inner peripheral surface 46a extends to the proximal opening 20 (see FIG. 2). The inner peripheral surface 46a is a portion where the intermediate gasket 36 and the base end gasket 38 are arranged in the initial state. The second inner diameter has a dimension that allows the intermediate gasket 36 and the base end gasket 38 to slide in the axial direction while being liquid-tightly adhered to the inner peripheral surface 46a.

The bypass structure 48 is provided between the first inner diameter portion 44 and the second inner diameter portion 46 . The axial length of the bypass structure 48 is longer than the axial length of the intermediate gasket 36 . The bypass structure 48 has an inner peripheral surface 48 a formed to have the same first inner diameter as the inner peripheral surface 44 a of the first inner diameter portion 44 . The inner peripheral surface 44a and the inner peripheral surface 48a are integrally connected.

A plurality of grooves 50 extending in the axial direction are provided on the inner peripheral surface 48a. The axial length of the groove portion 50 is longer than the axial length of the intermediate gasket 36 . The groove portion 50 is formed with a depth corresponding to the difference between the first inner diameter and the second inner diameter. A bottom portion 50 a of the groove portion 50 is formed as a curved surface having the same inner diameter as the inner peripheral surface 46 a of the second inner diameter portion 46 . Therefore, the bottom portion 50a and the inner peripheral surface 46a are connected in the same plane without a step.

In the bypass structure 48, a plurality of grooves 50 are arranged at regular intervals in the circumferential direction. The number of grooves 50 need only be two or more, and can be increased or decreased as appropriate according to the volume of the housing space 34 of the syringe outer cylinder 12 and the viscosity of the liquid agent B. For example, when the volume of the housing space 34 of the syringe outer cylinder 12 is 2.25 ml, the number of grooves 50 may be 8 to 24. Further, when the volume of the housing space 34 of the syringe outer cylinder 12 is 5 ml, 16 to 48 grooves 50 may be provided.

Next, the cross-sectional shape of the groove portion 50 will be described with reference to FIG. The groove 50 of this embodiment has an anti-clogging structure that prevents the compressed intermediate gasket 36 from entering and blocking. The blocking prevention structure is realized by the shape of the side wall portion 50b of the groove portion 50. As shown in FIG. As shown, the groove portion 50 has a bottom portion 50a and a pair of side wall portions 50b formed on both sides of the bottom portion 50a. The side wall portion 50b has a curved portion 52 with a rounded end on the inner peripheral surface 48a side. This curved portion 52 is configured with an arc-shaped curved surface having a radius of curvature larger than a predetermined radius in order to facilitate the withdrawal of the second mold 64 in the manufacturing process to be described later and to prevent the intermediate gasket 36 from being damaged during sliding. be done. The radius of curvature of this curved portion 52 can be, for example, about 0.08 mm.

Further, in the side wall portion 50b, a straight portion 54 extending linearly toward the bottom portion 50a is formed on the far side of the curved portion 52. As shown in FIG. A rear end portion of the straight portion 54 is connected to the bottom portion 50 a via a rear curved portion 56 . In this embodiment, the angle θ between the straight portion 54 and the inner peripheral surface 48a adjacent to the side wall portion 50b is 120°. The angle θ is not limited to 120°, and can be appropriately set within the range of 60° to 120° as shown in modification 1 and modification 2 described later. The other side wall portion 50b of the groove portion 50 is also formed with a curved portion 52 and a straight portion 54 which are formed in line symmetry. In the example of FIG. 4, the angle θ is 120°, and the groove portion 50 is a tapered groove that is narrower on the back side than on the inlet side. If the angle θ exceeds 120°, the intermediate gasket 36 may enter the groove 50 and block the groove 50 . Therefore, it is preferable that the angle θ is 120° or less.

The width W between the upper end of the straight portion 54 of one side wall portion 50b and the upper end of the straight portion 54 of the other side wall portion 50b is the depth D of the groove portion 50 (the radial distance between the bottom portion 50a and the inner peripheral surface 48a). can be made smaller than With this configuration, it is possible to prevent the intermediate gasket 36 from entering deep into the groove portion 50 . Note that the dimension of the width W may be equal to or greater than the dimension of the depth D. However, when the width W is extremely larger than the depth D, the intermediate gasket 36 tends to enter the bottom portion 50a of the groove portion 50, and the groove portion 50 tends to be closed.

As shown in FIG. 3 , an inclined surface 58 connecting to the inner peripheral surface 46 a is formed at the proximal end portion of the inner peripheral surface 48 a of the bypass structure 48 having the groove 50 . The inclined surface 58 is configured so that the intermediate gasket 36 and the proximal end gasket 38 can easily ride on the inner peripheral surface 48a, and the intermediate gasket 36 and the proximal end gasket 38 can slide smoothly.

As shown in FIG. 2, the distal end portion of the pusher 18 is connected to the proximal end gasket 38 . As the user displaces the pusher 18 in the distal direction, the proximal end gasket 38 slides in the syringe barrel 12 in the distal direction. As shown in FIG. 1, the pusher 18 has a screw structure 60 formed on its outer periphery. The screw structure 60 is configured to abut on a projection (not shown) provided on the grip 28 . When the threaded structure 60 of the pusher 18 reaches the protrusion of the grip 28, the pusher 18 needs to be pivoted in order to move the pusher 18 forward. Threaded structure 60 is configured to prevent rapid advancement of pusher 18 . Advancement of the pusher 18 pushes the proximal gasket 38 distally, thereby causing the intermediate gasket 36 to slide so as to be pushed distally.

The pusher 18 may be connected to the proximal gasket 38 when administering drug A and liquid drug B to the patient. Moreover, the pusher 18 only needs to be able to press the proximal end gasket 38 in the distal direction, and may be configured to simply contact the proximal end gasket 38 without being connected to the proximal end gasket 38 .

The prefilled syringe 10 of this embodiment is configured as described above, and a method for manufacturing the syringe outer cylinder 12 will be described below.

The syringe outer cylinder 12 is molded by injection molding a resin material. A first mold 62 and a second mold 64 shown in FIG. 5 are used for the injection molding. The first mold 62 has a concave portion 62 a having a shape corresponding to the outer diameter shape of the syringe outer cylinder 12 . The second mold 64 has a convex portion 64 a having a shape corresponding to the inner peripheral surface 12 a of the syringe outer cylinder 12 . An outwardly protruding rib 64b and an inclined portion 64c provided on the base end side of the rib 64b are formed in the middle of the convex portion 64a. The rib 64b is formed in a shape corresponding to the groove portion 50, and the inclined portion 64c is formed in a shape corresponding to the inclined surface 58. As shown in FIG.

A cavity 66 is formed between the first mold 62 and the second mold 64 . The syringe outer cylinder 12 is molded by introducing a molten resin material into the cavity 66 . Thereafter, the first mold 62 and the second mold 64 are pulled out from the syringe outer cylinder 12, which is a molded product, to obtain the syringe outer cylinder 12 of the present embodiment. Since the curved portion 52 is formed in the groove portion 50 , it is possible to prevent damage to the groove portion 50 when the second mold 64 is pulled out.

The action of the prefilled syringe 10 of this embodiment will be described.

The prefilled syringe 10 shown in FIG. 1 is put into use after a technique of mixing the drug A and the liquid medicine B (mixing technique) is performed just before use. The procedure for mixing the drug A and the liquid drug B is performed with the cap 16 removed and a needle unit (not shown) attached. At that time, the mixing procedure is performed with the tip of the prefilled syringe 10 facing upward and the proximal end facing downward. In the initial state, the intermediate gasket 36 is located proximal to the bypass structure 48 . When the pusher 18 is pushed in from this initial position, the proximal end gasket 38 slides toward the distal side. As the proximal end gasket 38 is displaced, the middle gasket 36 is displaced so as to be pushed out to the distal end side through the liquid agent B in the first chamber 40 .

Furthermore, by pushing the pusher 18 , the intermediate gasket 36 is displaced to a position overlapping the bypass structure 48 . In this state, the outer peripheral surface of the intermediate gasket 36 cannot be in close contact with the groove 50 , so the first chamber 40 and the second chamber 42 communicate with each other through the groove 50 of the bypass structure 48 .

When the pusher 18 is rotated, the screw structure 60 causes the pusher 18 to slowly move forward. Then, the liquid medicine B in the first chamber 40 moves to the second chamber 42 through the groove 50 of the bypass structure 48 . Since the grooves 50 are provided at a plurality of locations in the circumferential direction, the medicine A and the liquid medicine B mix at the plurality of locations in the circumferential direction. As a result, the drug A is uniformly mixed with the liquid drug B without agglomeration.

As shown in FIG. 6A, the groove portion 100 of the comparative example has a bottom portion 50a and side wall portions 50b that are curved to prevent breakage when sliding against the intermediate gasket 36 and to facilitate the withdrawal of the second mold 64. are formed in a continuous shape. In such a groove portion 100 , the outer peripheral portion of the intermediate gasket 36 conforms to the shape of the groove portion 100 and most of the groove portion 100 is filled with the intermediate gasket 36 . Therefore, the intermediate gasket 36 may be pushed out of the bypass structure 48 while the liquid agent B is not sufficiently transferred through the bypass structure 48 , and the liquid agent B may remain in the first chamber 40 .

On the other hand, as shown in FIG. 6B, the groove portion 50 of the present embodiment is provided with a straight portion 54 extending linearly on the side wall portion 50b. This makes it difficult for the intermediate gasket 36 to enter the bottom portion 50a of the groove portion 50 as shown in the drawing, thereby preventing the groove portion 50 from being blocked. Therefore, according to the groove portion 50 of the present embodiment, it is possible to reliably transfer the liquid medicine B from the first chamber 40 to the second chamber 42, thereby preventing poor mixing.

(Modification 1 of the first embodiment)
As shown in FIG. 7A, in this modified example, the cross-sectional shape of the groove portion 50A is different from the cross-sectional shape of the groove portion 50 of FIG. That is, the straight portion 54A of the groove portion 50A forms an angle θ of 90° (perpendicular) with the inner peripheral surface 48a. The groove portion 50A is configured as a substantially rectangular groove in which the side wall portion 50b rises perpendicularly to the bottom portion 50a.

As shown in FIG. 7B, according to this modification, the intermediate gasket 36 is more difficult to enter into the groove 50A, and the blockage of the intermediate gasket 36 in the groove 50A can be prevented more effectively.

(Modification 2 of the first embodiment)
As shown in FIG. 8A, in this modification, the cross-sectional shape of the groove portion 50B is different from the cross-sectional shape of the groove portion 50 in FIG. That is, the straight portion 54B of the groove portion 50B forms an angle θ of 60° (acute angle) with the inner peripheral surface 48a. The groove portion 50B is formed as a reverse tapered groove in which the width W2 on the far side is wider than the width W1 on the inner peripheral side. In this modified example, the angle θ can be appropriately selected within the range of 60° to 90°. If the angle θ between the straight portion 54B and the inner peripheral surface 48a is less than 60°, the side wall portion 50b may be damaged when the intermediate gasket 36 slides. It is preferable to set it as above.

As shown in FIG. 8B, according to this modification, the intermediate gasket 36 is more difficult to enter the groove 50B. Since it is difficult for the intermediate gasket 36 to conform to the shape in which the width W2 on the far side is wider than the width W1 on the inner peripheral side, the groove portion 50B of the present modification prevents the intermediate gasket 36 from closing. can be prevented.

The prefilled syringe 10 of this embodiment has the following effects.

The prefilled syringe 10 of the present embodiment includes a syringe outer cylinder 12 having a housing space 34 for housing a medicine formed therein, and having a nozzle 14 at the tip thereof, and a first chamber 40 and a second chamber 40 . The intermediate gasket 36 that separates the two chambers 42 into the two chambers 42, the proximal gasket 38 arranged on the proximal side of the intermediate gasket 36, and the inner peripheral surface 12a of the syringe outer cylinder 12 on the proximal side from the nozzle 14. a bypass structure 48 provided at an intermediate position spaced apart from the intermediate gasket 36 to form a gap with the outer peripheral portion of the intermediate gasket 36 to communicate the first chamber 40 and the second chamber 42; is formed extending in the axial direction on the inner peripheral surface 12a of the syringe outer cylinder 12 and has a plurality of

grooves

50, 50A, 50B arranged at intervals in the circumferential direction, and the

grooves

50, 50A, 50B are , has an anti-occlusion structure that is not completely blocked by the compressed intermediate gasket 36 .

According to the above configuration, it is possible to prevent the intermediate gasket 36 from entering the

grooves

50, 50A, and 50B, and to prevent poor migration of the liquid agent B due to clogging of the

grooves

50, 50A, and 50B.

In the prefilled syringe 10 described above, the side wall portions 50b of the

grooves

50, 50A, and 50B are formed with straight portions 54 that linearly extend toward the bottom portions 50a of the

grooves

50, 50A, and 50B. The provision of the straight portion 54 makes it difficult for the intermediate gasket 36 to reach the bottom portion 50a, thereby preventing clogging of the

grooves

50, 50A, and 50B.

In the prefilled syringe 10 described above, the angle between the outer side of the straight portion 54 and the inner peripheral surface 48a of the syringe outer cylinder 12 may be 60° to 120°.

In the prefilled syringe 10 described above, the groove portion 50B may be formed such that the width W2 on the inner side is wider than the width W1 on the inner peripheral side.

In the prefilled syringe 10 described above, the groove portion 50B has a pair of side wall portions 50b and a bottom portion 50a provided between the side wall portions 50b in a cross section perpendicular to the axial direction of the syringe outer cylinder 12. At least one of the side wall portions 50b may have an end portion on the far side of the groove portion 50B that protrudes further outward in the width direction than an end portion on the inner peripheral side of the groove portion 50B. According to this configuration, it is possible to prevent the intermediate gasket 36 from entering the groove 50B, and to prevent the liquid agent B from being transferred poorly.

In the prefilled syringe 10 described above, the groove portion 50B may have a reverse tapered cross section perpendicular to the axial direction of the syringe outer cylinder 12 . This configuration also prevents the intermediate gasket 36 from closing the groove 50B.

In the prefilled syringe 10 described above, the side wall portion 50b includes a curved portion 52 formed by rounding the corner between the inlet of the groove portion 50B and the inner peripheral surface 48a of the syringe outer cylinder 12, and a bottom portion 50a formed on the far side of the curved portion 52. A straight portion 54B may be formed that extends linearly toward . According to this configuration, it is possible to prevent chipping and breakage of the inlets of the

grooves

50, 50A, and 50B when the intermediate gasket 36 slides.

In the prefilled syringe 10 described above, the angle between the outer side of the straight portion 54B and the inner peripheral surface 48a of the syringe outer cylinder 12 may be 60° or more. According to this configuration, it is possible to prevent damage to the groove portion 50B due to an extremely thin wall thickness on the inner peripheral side of the side wall portion 50b.

In the prefilled syringe 10 described above, the width of the

grooves

50, 50A, 50B may be smaller than the depth of the

grooves

50, 50A, 50B. This configuration can prevent the intermediate gasket 36 from entering the

grooves

50, 50A, and 50B.

In the prefilled syringe 10 described above, the angle θ between the

straight portions

54, 54A, and 54B and the inner peripheral surface 48a of the syringe outer cylinder 12 can be 60° to 120°. According to this configuration, it is possible to prevent the

grooves

50, 50A, and 50B from being blocked by the intermediate gasket 36 while preventing damage to the

grooves

50, 50A, and 50B.

(Second embodiment)
As shown in FIG. 9, the prefilled syringe 10A of this embodiment differs from the prefilled syringe 10 described with reference to FIGS. 1 to 8B in the structure of the bypass structure 48A. In addition, in FIG. 9, the illustration of the configuration other than the syringe outer cylinder 12A of the prefilled syringe 10A is omitted. In the syringe outer cylinder 12A of FIG. 9, the same components as those of the syringe outer cylinder 12 of FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 9, the bypass structure 48A of the present embodiment has an annular recess 68 provided across the plurality of grooves 50. As shown in FIG. The annular recess 68 is formed as an annular groove extending along the entire circumference of the inner peripheral surface 12a of the syringe outer cylinder 12A. The annular concave portion 68 is formed by notching the inner peripheral surface 48a of the bypass structure 48A so as to expand outward. The annular recess 68 is formed shallower than the groove 50 . Such an annular recess 68 can be formed by cutting the inner peripheral surface 48a of the bypass structure 48 of the syringe outer cylinder 12 manufactured by the method described with reference to FIG.

As shown in FIG. 10, when the intermediate gasket 36 slides inside the bypass structure 48A of the present embodiment, the circular ring-shaped seal protrusion 36a formed on the outer peripheral portion of the intermediate gasket 36 enters the annular recess 68. The intermediate gasket 36 then stops at the bypass structure 48A. At this time, since the groove 50 of the bypass structure 48A is formed deeper than the annular recess 68, the communication between the first chamber 40 and the second chamber 42 is maintained through the groove 50. Therefore, the liquid medicine B in the first chamber 40 can be transferred to the second chamber 42 through the groove portion 50 .

Since the circular ring-shaped seal protrusion 36a formed on the outer peripheral portion of the intermediate gasket 36 enters the annular recess 68, the intermediate gasket 36 is prevented from passing through the bypass structure 48A before the transfer of the liquid agent B is completed. can. As a result, it is possible to prevent the liquid agent B from remaining in the first chemical chamber 40 . After the transfer of the liquid agent B is completed, the seal protrusion 36a of the intermediate gasket 36 can be separated from the annular recess 68 by further pushing the pusher 18 (see FIG. 1).

As described above, in the prefilled syringe 10A of the present embodiment, the bypass structure 48A has an annular recess 68 which is provided so as to cross the groove 50 and which is cut along the circumferential direction of the inner peripheral surface 48a of the syringe outer cylinder 12A. . According to this configuration, the intermediate gasket 36 can be stopped at the bypass structure 48A during the mixing procedure. As a result, the liquid medicine B in the first chamber 40 can be reliably transferred to the second chamber 42, and the medicine A and the liquid medicine B can be reliably mixed.

Also, in the prefilled syringe 10A described above, the groove portion 50 is formed deeper than the annular concave portion 68 . With this configuration, the communication between the first chamber 40 and the second chamber 42 is maintained through the groove 50 even when the intermediate gasket 36 is stopped at the bypass structure 48A. Therefore, the liquid medicine B in the first chamber 40 can be reliably transferred to the second chamber 42 through the groove portion 50 .

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention. stomach.

Claims

a syringe outer cylinder having a housing space for containing a medicine formed therein and having a nozzle at the tip;
an intermediate gasket that separates the housing space of the syringe barrel into two chambers, a first chamber and a second chamber;
a proximal gasket disposed on the proximal side of the intermediate gasket;
The inner peripheral surface of the syringe outer cylinder is provided at an intermediate position spaced apart from the nozzle toward the proximal end side, and a gap is formed between the outer peripheral portion of the intermediate gasket and the first chamber and the second chamber. and a bypass structure that communicates with the two chambers,
The bypass structure has a plurality of grooves extending in the axial direction on the inner peripheral surface of the syringe outer cylinder and arranged at intervals in the circumferential direction,
A prefilled syringe, wherein the groove has an anti-clogging structure that prevents the groove from being completely blocked by the compressed intermediate gasket.
The prefilled syringe according to claim 1, wherein a straight portion extending linearly toward the bottom of the groove is formed on the side wall of the groove.
The prefilled syringe according to claim 2, wherein the angle between the outer side of the straight portion and the inner peripheral surface of the syringe outer cylinder is 60° to 120°.
The prefilled syringe according to any one of claims 1 to 3, wherein the width of the groove on the inner side is wider than the width on the inner peripheral side.
A prefilled syringe according to claim 4,
The groove has a pair of side walls and a bottom provided between the side walls in a cross section perpendicular to the axial direction of the syringe barrel,
A prefilled syringe according to claim 1, wherein at least one of the sidewalls of the groove has a rear end of the groove protruding outward in the width direction from an inner peripheral end of the groove.
The prefilled syringe according to claim 4 or 5, wherein the groove has a reverse tapered cross section perpendicular to the axial direction of the syringe outer cylinder.
The prefilled syringe according to any one of claims 1 to 6, wherein the side wall of the groove is formed with a curved portion that rounds the corner between the entrance of the groove and the inner peripheral surface of the syringe outer cylinder. A prefilled syringe.
The prefilled syringe according to any one of claims 1 to 7, wherein the width of the groove is smaller than the depth of the groove.
a syringe outer cylinder having a housing space for containing a medicine formed therein and having a nozzle at the tip;
an intermediate gasket that separates the housing space of the syringe barrel into two chambers, a first chamber and a second chamber;
a proximal gasket disposed on the proximal side of the intermediate gasket;
The inner peripheral surface of the syringe outer cylinder is provided at an intermediate position spaced apart from the nozzle toward the proximal end side, and a gap is formed between the outer peripheral portion of the intermediate gasket and the first chamber and the second chamber. and a bypass structure that communicates with the two chambers,
The bypass structure is
a plurality of grooves formed in the inner peripheral surface of the syringe outer cylinder to extend in the axial direction and arranged at intervals in the circumferential direction;
An annular recess provided to traverse the groove and notching the inner peripheral surface of the syringe outer cylinder along the circumferential direction,
prefilled syringe.
The prefilled syringe according to claim 9, wherein the groove is deeper than the annular recess.