Syringe assembly and drug delivery device

Abstract

Provided is a syringe assembly (12A) and a medicine administration apparatus (10) capable of suppressing variation in the limit pressure resistance of a seal member (46). In the syringe assembly (12A), a seal member (46) is held in a manner that is pushed against between a push surface (48) of a cap (44) and a seal surface (60) of a front-end nozzle portion (56) of a syringe (24). The seal member (46) is held in a manner that is pushed axially in a push space (64) of the entire area of the opposing portions of the push surface (48) and the seal surface (60), in which the inner peripheral side of the gap between the push surface (48) and the seal surface (60) is narrowest.

Description

TECHNICAL FIELD

[0001] The present application relates to a syringe assembly that seals a drug solution and a drug solution administration apparatus. BACKGROUND

[0002] In the past, a drug solution administration apparatus of an injection pump type that administers a drug solution filled in a barrel to a living body under the pushing action of a plunger has been proposed (International Publication No. 2019 / 182031). The drug solution administration apparatus is provided with a syringe assembly in which a drug solution is filled. The syringe assembly is provided with a syringe having a front-end nozzle portion, a cap fixed to the front-end nozzle portion, and a sealing member composed of an elastic body that is arranged between the cap and the front-end nozzle portion and seals the opening of the front-end nozzle portion. SUMMARY

[0003] In the assembly process of the syringe assembly, the compression of the sealing member becomes uneven in the circumferential direction, resulting in a deviation in the internal pressure (limiting pressure) at which liquid leakage occurs, and thus there is a problem that a syringe assembly with a very low limiting pressure can occur.

[0004] With regard to the cap, a process of aligning the axis of the cap coaxially with the axis of the syringe and inserting the cap toward the front-end nozzle portion is performed by a mounting device. However, it has been found that when the cap is assembled, the axis of the cap can sometimes be inclined with respect to the axis of the syringe, resulting in a deviation in the crushing load of the sealing member based on the front-end nozzle portion, and thus a deviation in the limiting pressure.

[0005] Therefore, an object of one embodiment is to provide a syringe assembly and a drug solution administration apparatus that can suppress a deviation in the limiting pressure of a sealing member.

[0006] One aspect of the present application provides a syringe assembly provided with: a syringe having a front-end nozzle portion; a cap fixed to the front-end nozzle portion; and a sealing member composed of an elastic body that is arranged between the cap and the front-end nozzle portion and seals the front-end nozzle portion, the cap having a pushing surface that makes surface contact with the front end of the sealing member and pushes the sealing member toward the base end side, the front-end nozzle portion having, at the front end, a sealing surface that makes surface contact with the base end of the sealing member opposite the pushing surface, and a front-end opening that is formed on the inner circumferential side of the sealing surface and communicates with the inner cavity of the syringe, the sealing member blocking the front-end opening and being held by being pushed in the axial direction in a pushing space of the entire region of the opposing portion of the pushing surface and the sealing surface, the inner circumferential side being the narrowest in the gap between the pushing surface and the sealing surface in the pushing space.

[0007] Another aspect provides a medicine liquid administering apparatus including: the syringe assembly according to the above aspect; a gasket slidably arranged in the syringe; a plunger assembly configured to push the gasket in the forward direction; and a drive mechanism configured to drive the plunger assembly.

[0008] The syringe assembly and the medicine liquid administering apparatus according to the above aspect can uniformly distribute the crushing load of the seal member by the forward nozzle portion, and can suppress the variation in the limit pressure. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic view of a medicine liquid administering apparatus including the syringe assembly according to the first embodiment.

[0010] Figure 2 is a perspective view of the medicine liquid administering apparatus according to Figure 1 in a state where the housing is removed.

[0011] Figure 3 is a cross-sectional view of the forward end side of the syringe assembly according to Figure 2

[0012] Figure 4 is a cross-sectional view of the forward end side of the syringe assembly according to the comparative example.

[0013] Figure 5 is a cross-sectional view illustrating the operation of the syringe assembly according to Figure 3

[0014] Figure 6 is a graph showing the measurement results of the limit pressure of the syringe assembly according to the experimental example 1 (comparative example).

[0015] Figure 7 is a graph showing the measurement results of the limit pressure of the syringe assembly according to the experimental example 2 (first embodiment).

[0016] Figure 8 is a cross-sectional view of the forward end side of the syringe assembly according to the second embodiment.

[0017] Figure 9 is a cross-sectional view illustrating the operation of the syringe assembly according to Figure 8

[0018] Figure 10 is a cross-sectional view of the forward end side of the syringe assembly according to the third embodiment.

[0019] Figure 11 is a cross-sectional view illustrating the operation of the syringe assembly according to Figure 10

[0020] Figure 12 is a cross-sectional view of the forward end side of the syringe assembly according to the fourth embodiment.​​​​

[0021] Figure 13 is a sectional view showing the operation of the syringe assembly Figure 12 DETAILED DESCRIPTION

[0022] Hereinafter, the syringe assemblies 12A, 12B, 12C, 12D and the medicine administering apparatus 10 will be described in detail with reference to the preferred embodiments and the drawings. Further, in the second to fourth embodiments, only the main parts will be shown, and the same reference numerals will be assigned to the same or similar structures as those of the first embodiment, and detailed description thereof will be omitted.

[0023] [First Embodiment]

[0024] Figure 1 The medicine administering apparatus 10 shown in the drawing is used in order to administer a medicine M into a living body. The medicine administering apparatus 10 continuously administers the medicine M filled in the syringe assembly 12A into the living body for a long time (for example, several minutes to several hours) under the pushing action of the plunger assembly 14. The medicine administering apparatus 10 can also intermittently administer the medicine M into the living body. As the medicine M, for example, a protein preparation, an analgesic, a diuretic, and the like can be listed.

[0025] As shown in the drawing, Figure 1 In use, the medicine administering apparatus 10 is connected with a patch-type needle tube 17 as an administering tool 16. The medicine M discharged from the syringe assembly 12A is injected into the body of a patient via the needle tube 17. The needle tube 17 has a connector 18 connectable with the front-end nozzle portion 56 of the syringe assembly 12A, a flexible liquid delivery tube 19 having one end connected with the connector 18, a patch portion 20 attachable to the skin S and connected with the other end of the liquid delivery tube 19, and a puncture needle 21 protruding from the patch portion 20. The puncture needle 21 punctures the skin S substantially perpendicularly. Further, the puncture needle 21 can be a puncture needle which obliquely punctures the skin S.

[0026] As shown in the drawing, Figure 1 or Figure 2 The medicine administering apparatus 10 has the syringe assembly 12A having the syringe 24 filled with the medicine M, the gasket 26 slidably arranged in the syringe 24, the plunger assembly 14 which is axially (in the direction of the arrow X) extendable and which is capable of pressing the gasket 26 in the front-end direction (in the direction of the arrow X1), the drive mechanism 28 which drives the plunger assembly 14, the battery 30 which supplies electric power required for the operation of the medicine administering apparatus 10, the control portion 32 which controls the drive mechanism 28, the chassis structure 34 which supports the syringe assembly 12A, the plunger assembly 14, and the drive mechanism 28, and the housing 36 which houses these components. ​

[0027] As Figure 2 shown, the syringe assembly 12A is provided with: the syringe 24 having the front nozzle portion 56; the cap 44 mounted on the front nozzle portion 56 of the syringe 24; and the seal member 46 disposed between the front nozzle portion 56 and the cap 44.

[0028] The syringe 24 is formed in a hollow cylindrical shape. Specifically, the syringe 24 has: a body portion 50 having an inner cavity 13 capable of being filled with the medical liquid M; and a flange portion 54 protruding outward from an outer peripheral surface of the body portion 50. The medical liquid M is pre-filled in the syringe 24. The syringe 24 can be composed of a material having transparency.

[0029] As Figure 3 shown, the front end portion of the front nozzle portion 56 is provided with an engagement protrusion 56a. The engagement protrusion 56a protrudes to the radial outer side and is formed in a ring shape extending one turn in the circumferential direction. The engagement protrusion 56a has: an engagement surface 56al for engagement of the later-described claw portions 74a, 74b of the cap 44; and an inclined surface 56a2 formed at a position on the front end side from the engagement surface 56al and tapered toward the front end direction. The engagement surface 56al is a flat surface perpendicular to the axis of the front nozzle portion 56. In the outer peripheral surface of the front nozzle portion 56, a ring-shaped groove 56b recessed to the radial inner side is formed at the base end side of the engagement protrusion 56a.

[0030] On the outer periphery of the base end portion of the front nozzle portion 56, an anti-shake protrusion 56e for preventing the cap 44 from shaking is provided. The anti-shake protrusion 56e protrudes to the radial outer side and is formed in a ring shape extending one turn in the circumferential direction. The outer peripheral surface of the anti-shake protrusion 56e extends along the axis of the front nozzle portion 56. The base end of the anti-shake protrusion 56e is continuous with the front end of the shoulder portion 52.

[0031] On the front end of the front nozzle portion 56, a seal surface 60 perpendicular to the axial direction is formed. The seal surface 60 is formed in a circular ring shape on the outer peripheral side of the front end opening 58. The substantially entire area in the radial direction of the seal surface 60 is in surface contact with the seal member 46, and high sealability (pressure resistance) is exerted, and leakage of the medical liquid M can be prevented even if a relatively high pressure of the inner cavity 13 acts. The inner diameter of the seal surface 60 can be set to about 0.5 to 5.0 mm, and the outer diameter can be set to about 2.0 to 9.0 mm.

[0032] On the inner peripheral side of the seal surface 60, an annular protrusion 62 protruding toward the axial front end side (the push surface 48) is formed. The annular protrusion 62 is formed in a ring shape along the inner peripheral portion of the seal surface 60. The protruding height of the annular protrusion 62 is formed to a degree that does not interfere with the face contact of the outer peripheral portion 46d of the seal member 46 with the seal surface 60. The annular protrusion 62 prevents the movement of the constituent material of the seal member 46 at the time of mounting the cap 44. As to the dimensions of the annular protrusion 62 that functions as such, for example, the axial protruding height can be set to about 0.05 to 1.5 mm, and the radial (width direction) dimension can be set to about 0.05 to 1.5 mm.

[0033] The seal member 46 is pierced by the needle 18a provided to the connector 18 at the time of connecting the connector 18 to the front end nozzle portion 56 as shown in the drawing. The seal member 46 is constituted of an elastic resin material such as a rubber material or an elastomer material formed in a plate shape. The seal member 46 is fixed to the front end nozzle portion 56 of the syringe assembly 12A by the cap 44, and seals the front end opening 58 of the front end nozzle portion 56. The seal member 46 is held in a state of being elastically compressed in the axial direction between the seal surface 60 of the front end nozzle portion 56 and the push surface 48 of the cap 44. The seal member 46 is formed in a disc shape. Figure 1

[0034] The seal member 46 has a seal main body portion 46a constituting the central portion in the thickness direction, a front end protrusion portion 46b protruding in the front end direction from the front end side of the seal main body portion 46a, and a base end protrusion portion 46c protruding in the base end direction from the base end side of the seal main body portion 46a. The front end protrusion portion 46b slightly protrudes in the front end direction compared to the push surface 48 of the cap 44. The face of the front end side of the front end protrusion portion 46b can also be located at the same axial position as the push surface 48 of the cap 44, or at a position on the base end side from the push surface 48.

[0035] The outer peripheral portion 46d of the front end protrusion portion 46b and the base end protrusion portion 46c of the seal member 46 is disposed in the push space 64 formed between the seal surface 60 of the front end nozzle portion 56 and the push surface 48 of the cap 44. In the push space 64, the base end of the outer peripheral portion 46d of the seal member 46 is in face contact with substantially the entire area in the radial direction of the seal surface 60, and is thus tightly attached, thereby exhibiting pressure resistance. In addition, the front end side of the outer peripheral portion 46d of the seal member 46 is in face contact with the push surface 48 of the cap 44. Furthermore, the outer peripheral portion 46d is pushed in the axial direction by the push surface 48 and the seal surface 60.

[0036] ​The push space 64 is a space between the sealing surface 60 of the front nozzle portion 56 and a portion of the push surface 48 of the cap 44 opposite the sealing surface 60, and is formed in a circular ring shape on the outer peripheral side of the front end opening 58 of the front nozzle portion 56. In the present embodiment, a ring-shaped protrusion 62 is formed along the inner peripheral side of the sealing surface 60, and thus the width D (gap) in the axial direction of the push space 64 is narrower on the inner peripheral side Dl than on the outer peripheral side D2. That is, the width D in the axial direction of the push space 64 is narrowest on the inner peripheral side.

[0037] The cap 44 has a base portion 66 provided on the front end side of the cap 44, and a cylindrical mounting portion 72 extending from the base portion 66 in the axial direction of the cap 44 toward the base end side and covering the outer side of the front nozzle portion 56. The base portion 66 is formed with the push surface 48 on the base end side that makes surface contact with the sealing member 46. The push surface 48 is formed in a circular ring shape around the central through-hole 70. In the central portion of the base portion 66, the through-hole 70 is formed that penetrates in the axial direction to expose the front end protrusion 46b of the sealing member 46.

[0038] The through-hole 70 is a hole portion formed in a circular shape when viewed in the axial direction, and is formed on the same axis as the cap 44. The through-hole 70 is formed in the front end wall 68 of the base portion 66. The front end protrusion 46b of the sealing member 46 is inserted into the through-hole 70.

[0039] The mounting portion 72 has claw portions 74a, 74b, a first column portion 76, and a second column portion 78. The two claw portions 74a, 74b face each other across the central axis of the cap 44 and are formed at positions away from the base portion 66 toward the base end side. The claw portions 74a, 74b protrude toward the inside from the inner peripheral surface of the mounting portion 72. The cap 44 is mounted to the front nozzle portion 56 by engagement of the two claw portions 74a, 74b with the engagement protrusion 56a of the front nozzle portion 56. That is, the cap 44 is prevented from coming off the front nozzle portion 56 by engagement of the two claw portions 74a, 74b with the base end (engagement surface 56al) of the engagement protrusion 56a of the front nozzle portion 56. The two claw portions 74a, 74b each extend in a circular arc shape in the circumferential direction along the inner peripheral surface of the mounting portion 72.

[0040] The first column portion 76 is provided on the outer side of one claw portion 74a in the circumferential direction of the mounting portion 72 and extends toward the base end side along the axis of the cap 44. The second column portion 78 is provided on the outer side of the other claw portion 74b in the circumferential direction of the mounting portion 72 and extends toward the base end side along the axis of the cap 44. The inner peripheral surfaces of the first and second column portions 76, 78 abut against the shake prevention protrusion 56e of the front nozzle portion 56, thereby preventing tilting of the cap 44 with respect to the front nozzle portion 56. The first and second column portions 76, 78 are integrally connected to the base portion 66 via a side wall portion 80. Two side holes 82 are formed on the front end side of the side wall portion 80. The side holes 82 penetrate the side wall portion 80 in the radial direction.

[0041] In Figure 2 which the gasket 26 liquid-tightly seals the proximal end side of the inner cavity 13 of the syringe 24. In the initial state of the drug liquid administration apparatus 10, the gasket 26 is located on the distal end side compared to the proximal end of the syringe 24. The outer side of the gasket 26 is liquid-tightly in contact with the inner peripheral surface of the syringe 24 (the main body portion 50). The pre-filled syringe 15 is constituted by the syringe assembly 12A, the drug liquid M, and the gasket 26.

[0042] The plunger assembly 14 is configured to advance the gasket 26 in the syringe 24 and push out the drug liquid M from the syringe assembly 12A. In the initial state of the drug liquid administration apparatus 10, the distal end side of the plunger assembly 14 is inserted in the proximal end side of the syringe 24. The drive mechanism 28 has a motor 31 that uses the battery 30 as a power source and is driven and controlled under the control of the control portion 32, and a drive gear 37 fixed to the output shaft of the motor 31.

[0043] The chassis structure 34 is disposed inside the housing 36 (refer to Figure 1 ). The syringe assembly 12A, the drive mechanism 28, and the plunger assembly 14 are respectively fixed to prescribed positions of the chassis structure 34. The chassis structure 34 has a chassis main body member 34a, and a motor holding member 34b fixed to the chassis main body member 34a and holding the motor 31 between the chassis main body member 34a and the motor holding member 34b.

[0044] The chassis main body member 34a has a flange holding portion 34c that protrudes upward and holds the flange portion 54 of the syringe 24. The holding groove 34d into which the flange portion 54 is inserted is provided on the flange holding portion 34c.

[0045] In Figure 1 which the housing 36 is a hollow member configured to house the above-described syringe assembly 12A, the gasket 26, the plunger assembly 14, the drive mechanism 28, the battery 30, the control portion 32, and the chassis structure 34. The distal end nozzle portion 56 of the syringe assembly 12A protrudes from the housing 36, and the cap 44 is exposed to the outside. The window portion 36w composed of a material having transparency is provided on the upper surface 36a of the housing 36.

[0046] The drug liquid administration apparatus 10 can be configured to be a patch type that is attached to the skin S of a patient, for example. In the case of such a patch type, a patch-shaped attachment portion (adhesive portion) that can be attached to the skin S is provided on the bottom surface 36b of the housing 36. In the initial state of the drug liquid administration apparatus 10, a peelable protective sheet is attached to the attachment surface of the attachment portion.

[0047] Further, the drug liquid administration apparatus 10 is provided with a hook or a clip or the like as a mounting member on the bottom surface 36b of the housing 36, and is mounted by being hooked to a patient's clothes (for example, the waist of pants, or the like) or the like.

[0048] Next, the operation of the syringe assembly 12A (assembly process) will be described with reference to Comparative Example 1.

[0049] The assembly process of the syringe assembly 12A is performed in the order of a syringe preparation process, a seal member preparation process, a cap preparation process, a cap assembly process, and a cap mounting process (refer to Figure 5 ).

[0050] In the syringe preparation process, the above-described syringe 24 provided with the tip nozzle portion 56 having the tip opening 58 and the engagement protrusion 56a provided to the outer peripheral surface is prepared.

[0051] In the seal member preparation process, the plate-shaped seal member 46 having elasticity is prepared.

[0052] In the cap preparation process, the cap 44 composed of a hard resin material and provided with the base portion 66 provided to the tip and the cylindrical mounting portion 72 extending from the base portion 66 in the axial direction of the cap 44 toward the base end is prepared.

[0053] In the cap assembly process, the seal member 46 is inserted into the inner peripheral side of the mounting portion 72 of the cap 44 so that the seal member 46 is in surface contact with the push surface 48. In addition, the tip protrusion 46b of the seal member 46 is inserted into the through hole 70.

[0054] In the cap mounting process, the tip nozzle portion 56 is inserted into the mounting portion 72 of the cap 44 in which the seal member 46 is mounted. Then, the cap 44 is pressed in toward the base end side until the two claw portions 74a, 74b of the mounting portion 72 pass over the engagement protrusion 56a of the tip nozzle portion 56. Then, the tip opening 58 of the tip nozzle portion 56 is sealed by the seal member 46.

[0055] The above-described cap mounting process is performed by pressing the cap 44 toward the tip nozzle portion 56 while holding the cap 44 and the syringe 24 by the jig of the mounting device. In Figure 5 the state in which the cap mounting process is completed, the inner peripheral surface of the mounting portion 72 of the cap 44 is in abutment with the anti-shake protrusion 56e of the tip nozzle portion 56, and the cap 44 is assembled without inclination. However, in the middle of pressing the cap 44 into the tip nozzle portion 56, there are cases in which the cap 44 is inclined with respect to the tip nozzle portion 56 due to various reasons, as shown in Figure 4 and Figure 5 .

[0056] As shown in Figure 4As shown, in the comparative example syringe assembly 112A, no annular protrusion 62 is formed on the sealing surface 160 of the front nozzle portion 156. During the pressing of the cap 44, the sealing member 46 makes surface contact with the pressing surface 48 of the cap 44 and the sealing surface 160 of the front nozzle portion 156 to form a pressing space 164. In the comparative example, if the cap 44 is tilted, the axial width D1 of the inner circumference of the pressing space 164 becomes larger than the axial width D2 of the outer circumference, opening into a V-shape by gradually widening towards the inner circumference. Therefore, during the pressing of the cap 44 towards the base end, the material of the sealing member 46 moves away from the pressing space 164 toward the unpressed portion.

[0057] As a result, a deviation occurs in the compressive load on the sealing surface 160 in the circumferential direction of the sealing member 46, and the ultimate pressure resistance is reduced. That is, in the part of the sealing member 46 that initially abuts against the sealing surface 160, there is a lack of material thickness, and the sealing performance between the sealing surface 160 and the sealing member 46 is reduced after the cap 44 is installed.

[0058] In contrast, such as Figure 5 As shown, in the syringe assembly 12A of this embodiment, an annular protrusion 62 is formed on the inner periphery of the sealing surface 60 of the front nozzle portion 56. During the pressing of the cap 44, the sealing member 46 makes surface contact with the pressing surface 48 of the cap 44 and the sealing surface 60 of the front nozzle portion 56 to form a pressing space 64. As shown, by providing the annular protrusion 62, the axial width D1 of the inner periphery of the pressing space 64 becomes smaller than the axial width D2 of the outer periphery, and the axial width D1 of the inner periphery of the pressing space 64 becomes the narrowest. This prevents movement of the constituent material of the sealing member 46. As a result, the compressive load on the sealing surface 60 in the circumferential direction of the sealing member 46 becomes more uniform, which improves the ultimate pressure resistance.

[0059] Next, the syringe assembly 112A of the actual comparative example (Experimental Example 1) and the syringe assembly 12A of this embodiment (Experimental Example 2) will be described, and the results of the measurement of the ultimate pressure resistance when liquid leakage occurs when the gasket 26 is pressed in will be presented.

[0060] In Experiment 1, for Figure 4 The syringe assembly 112A of Comparative Example 1 shown was used to prepare five samples of water sealed in it for testing. Furthermore, a test plunger was used to press the washer 26 in place, and the displacement (mm) of the test plunger and the test force (N) as the input load to the test plunger were measured.

[0061] exist Figure 6 The measurement results of Experiment 1 are shown in the figure.Figure 6 In the diagram, the vertical axis represents the test force (N), and the horizontal axis represents the displacement of the test plunger (mm). The test force reflects the internal pressure of the syringe 24 and increases with the increase of the displacement of the test plunger. If leakage occurs, the test force will remain constant even if the displacement of the test plunger increases. Therefore, in Figure 6 The maximum value of the test force reflects the ultimate pressure resistance based on the sealing component 46.

[0062] As shown in the figure, in Experiment 1, the maximum value of the test force deviated significantly within the range of 80–200 N. For both samples, the ultimate withstand pressure was 80–120 N, showing extremely low values.

[0063] On the other hand, in Experiment 2, for Figure 3 The syringe assembly 12A of this embodiment, as shown, was used to prepare five water-sealed samples, and its ultimate pressure resistance was evaluated using the same method as in Experimental Example 1. Figure 7 The measurement results of Experiment Example 2 are shown in the figure.

[0064] like Figure 7 As shown, in Experimental Example 2 (this embodiment), it can be confirmed that the maximum value of the test force converges within the range of 200 to 240 N, the deviation of the ultimate withstand pressure is suppressed, and no sample with extremely low ultimate withstand pressure is produced.

[0065] The syringe assembly 12A and the drug delivery device 10 of this embodiment have the following effects.

[0066] The syringe assembly 12A of this embodiment includes: a syringe 24 having a front nozzle portion 56; a cap 44 fixed to the front nozzle portion 56; and a sealing member 46 made of an elastomer disposed between the cap 44 and the front nozzle portion 56 and sealing the front nozzle portion 56. In this syringe assembly 12A, the cap 44 has a pressing surface 48 that makes surface contact with the front end of the sealing member 46 and pushes the sealing member 46 toward the base end. The front nozzle portion 56 has a sealing surface 60 at its front end that faces the pressing surface 48 and makes surface contact with the base end of the sealing member 46, and a front opening 58 formed on the inner circumferential side of the sealing surface 60 and communicating with the inner cavity 13 of the syringe 24. The sealing member 46 blocks the front opening 58 and is held by axial pressing in the pressing space 64 of the entire area of ​​the opposing portion of the pressing surface 48 and the sealing surface 60. In the pressing space 64, the inner circumferential side of the gap between the pressing surface 48 and the sealing surface 60 is the narrowest.

[0067] According to the above structure, when the cap 44 is attached to the front nozzle portion 56, movement of the material of the seal member 46 can be prevented even if the cap 44 is tilted with respect to the front nozzle portion 56. Thus, deviation of the compressive load in the circumferential direction of the seal member 46 can be suppressed, and thus reduction in the limit pressure resistance of the seal member 46 can be prevented.

[0068] In the above-described syringe assembly 12A, a ring-shaped protrusion 62 that is formed annularly on the inner peripheral side and protrudes toward the pressing surface 48 can be provided on the seal surface 60. By providing the ring-shaped protrusion 62 on the inner peripheral side as described above, the inner peripheral side of the gap between the pressing surface 48 and the seal surface 60 in the pressing space 64 can be made the narrowest, and thus movement of the material of the seal member 46 can be prevented.

[0069] In addition, the medical liquid administration apparatus 10 of the present embodiment includes the syringe assembly 12A, the gasket 26 that is slidably arranged in the syringe 24, the plunger assembly 14 that is capable of pressing the gasket 26 in the front end direction, and the drive mechanism 28 that drives the plunger assembly 14, wherein the syringe assembly 12A includes the syringe 24 that has the front nozzle portion 56, the cap 44 that is fixed to the front nozzle portion 56, and the seal member 46 that is arranged between the cap 44 and the front nozzle portion 56 and seals the front nozzle portion 56, the cap 44 having the pressing surface 48 that is in surface contact with the front end of the seal member 46 and presses the seal member 46 in the base end direction, the front nozzle portion 56 having the seal surface 60 that is opposite to the pressing surface 48 and is in surface contact with the base end of the seal member 46 at the front end, and the front end opening 58 that is formed on the inner peripheral side of the seal surface 60 and communicates with the inner cavity 13 of the syringe 24, the seal member 46 blocking the front end opening 58 and being held by being pressed in the axial direction in the pressing space 64 of the entire region of the opposing portion of the pressing surface 48 and the seal surface 60, in which the inner peripheral side of the gap between the pressing surface 48 and the seal surface 60 is the narrowest.

[0070] According to the above structure, the medical liquid administration apparatus 10 in which deviation of the limit pressure resistance of the seal member 46 is suppressed, and thus liquid leakage is less likely to occur.

[0071] [2nd Embodiment]

[0072] As Figure 8As shown, in the syringe assembly 12B of this embodiment, the sealing surface 60B of the front nozzle portion 56 is configured as an inclined surface that is inclined relative to the pressing surface 48 of the cap 44. The inner peripheral side of the sealing surface 60B adjacent to the front opening 58 protrudes most towards the pressing surface 48. That is, the sealing surface 60B is configured as an inclined surface that gradually protrudes towards the pressing surface 48 from the outer peripheral side to the inner peripheral side. Similarly, in the syringe assembly 12B, the axial width D1 of the inner peripheral side of the pressing space 64B that pushes the outer peripheral portion 46d of the sealing member 46 axially is the narrowest.

[0073] like Figure 9 As shown, during the cap installation process, even when the cap 44 is tilted, the axial width D1 of the inner circumferential side of the pressing space 64B is the narrowest, thus preventing movement of the constituent material of the sealing member 46. Therefore, according to this embodiment, the circumferential pressing load of the sealing member 46 is also uniformized, suppressing deviations in the ultimate pressure resistance.

[0074] The syringe assembly 12B of this embodiment has the following effects.

[0075] In the syringe assembly 12B of this embodiment, the sealing surface 60B is composed of an inclined surface that gradually protrudes towards the aforementioned pressing surface from the outer peripheral side toward the inner peripheral side. By configuring it in this way, the circumferential pressing load of the sealing member 46 is uniformized, thereby suppressing deviations in the ultimate pressure resistance.

[0076] [Third Implementation]

[0077] like Figure 10 As shown, in this embodiment, the syringe assembly 12C has an annular protrusion 62C protruding towards the sealing surface 60 of the front nozzle portion 56 on the inner periphery of the pressing surface 48C of the cap 44. The annular protrusion 62C is formed in an annular shape along the through hole 70 of the cap 44. On the sealing member 46, an annular groove 46e is formed on the portion corresponding to the annular protrusion 62C, and the annular protrusion 62C is inserted into the annular groove 46e.

[0078] On the other hand, the sealing surface 60 of the front nozzle portion 56 is formed as a flat surface perpendicular to the axial direction. In the illustrated example, no annular protrusion 62 is formed on the sealing surface 60 (see reference). Figure 3 However, it is not limited to this; annular protrusions 62 may also be formed on the inner circumferential side of the sealing surface 60.

[0079] In this embodiment, the inner circumferential side of the pressing surface 48C adjacent to the through hole 70 protrudes most towards the sealing surface 60. Therefore, in the pressing space 64C of the pressing sealing member 46, the axial width D1 of the pressing space 64C on the inner circumferential side is the narrowest.

[0080] like Figure 11 As shown, during the cap installation process, even when the cap 44 is tilted, the axial width D1 of the inner circumferential pressing space 64C is the narrowest, thus preventing movement of the constituent material of the sealing member 46. Therefore, according to this embodiment, the circumferential pressing load of the sealing member 46 is also uniformized, suppressing deviations in the ultimate pressure resistance.

[0081] The syringe assembly 12C of this embodiment has the following effects.

[0082] In the syringe assembly 12C of this embodiment, an annular protrusion 62C is provided on the pressing surface 48C, which is formed in a ring shape along the inner circumference and protrudes toward the sealing surface 60. By configuring it in this way, the circumferential pressing load of the sealing member 46 is uniformized, and deviations in the ultimate pressure resistance can be suppressed.

[0083] [Fourth Implementation]

[0084] like Figure 12 As shown, in the syringe assembly 12D of this embodiment, the pressing surface 48D of the cap 44 is configured as an inclined surface that is inclined relative to the sealing surface 60 of the front nozzle portion 56. The inner peripheral side of the pressing surface 48D adjacent to the through hole 70 protrudes most towards the sealing surface 60. That is, the pressing surface 48D is configured as an inclined surface that gradually protrudes towards the sealing surface 60 from the outer peripheral side to the inner peripheral side. In addition, the upper end of the outer peripheral portion 46d of the sealing member 46 in this embodiment is configured as an inclined surface that matches the inclination of the pressing surface 48D.

[0085] On the other hand, the sealing surface 60 of the front nozzle portion 56 is formed as a flat surface perpendicular to the axial direction. In the illustrated example, no annular protrusion 62 is formed on the sealing surface 60 (see reference). Figure 3 However, it is not limited to this; annular protrusions 62 may also be formed on the inner circumferential side of the sealing surface 60.

[0086] like Figure 13 As shown, during the cap installation process, even when the cap 44 is tilted, the axial width D1 of the inner circumferential pressing space 64D is the narrowest, thus preventing movement of the constituent material of the sealing member 46. Therefore, according to this embodiment, the circumferential pressing load of the sealing member 46 is also uniformized, suppressing deviations in the ultimate pressure resistance.

[0087] The syringe assembly 12D of this embodiment has the following effects.

[0088] In the syringe assembly 12D, the pressing surface 48D is constituted by an inclined surface inclined in a manner that it gradually protrudes toward the sealing surface 60 from the outer peripheral side toward the inner peripheral side. By being constituted in this way, the pressing load in the circumferential direction of the sealing member 46 is homogenized, and the variation in the limit pressure resistance can be suppressed.

[0089] In the above, the syringe assemblies 12A, 12B, 12C, 12D and the medicine administration apparatus 10 have been described taking preferred embodiments as examples, but the present application is not limited to the above examples, and various modifications can of course be made within the scope of the gist of the present application.

Claims

1. A syringe assembly comprising: a syringe having a front nozzle portion; a cap fixed to the front nozzle portion; and a sealing member made of an elastomer disposed between the cap and the front nozzle portion and sealing the front nozzle portion, wherein in the syringe assembly, The cap has a pressing surface that makes face contact with the front end of the sealing member and pushes the sealing member toward the base end. The front nozzle portion has a sealing surface at its front end that is opposite to the pressing surface and in surface contact with the base end of the sealing member, and a front opening formed on the inner circumferential side of the sealing surface and communicating with the inner cavity of the syringe. The sealing component blocks the front opening and is held in place by axial pressure within the entire pressing space of the opposing portions of the pressing surface and the sealing surface. Within the pressing space, the inner circumferential side of the gap between the pressing surface and the sealing surface is the narrowest. The sealing surface is provided with an annular protrusion that is formed in a ring shape along the inner circumference and protrudes toward the pressing surface. The radial width of the annular protrusion is 0.05 to 1.5 mm.

2. The syringe assembly as claimed in claim 1, wherein, The axial protrusion height of the annular protrusion is 0.05 to 1.5 mm.

3. A syringe assembly comprising: a syringe having a front nozzle portion; a cap fixed to the front nozzle portion; and a sealing member made of an elastomer disposed between the cap and the front nozzle portion and sealing the front nozzle portion, wherein in the syringe assembly, The cap has a pressing surface that makes face contact with the front end of the sealing member and pushes the sealing member toward the base end. The front nozzle portion has a sealing surface at its front end that is opposite to the pressing surface and in surface contact with the base end of the sealing member, and a front opening formed on the inner circumferential side of the sealing surface and communicating with the inner cavity of the syringe. The sealing component blocks the front opening and is held in place by axial pressure within the entire pressing space of the opposing portions of the pressing surface and the sealing surface. Within the pressing space, the inner circumferential side of the gap between the pressing surface and the sealing surface is the narrowest. The pressing surface has an annular protrusion that is formed in a ring shape along the inner circumference and protrudes toward the sealing surface.

4. A syringe assembly comprising: a syringe having a front nozzle portion; a cap fixed to the front nozzle portion; and a sealing member made of an elastomer disposed between the cap and the front nozzle portion and sealing the front nozzle portion, wherein in the syringe assembly, The cap has a pressing surface that makes face contact with the front end of the sealing member and pushes the sealing member toward the base end. The front nozzle portion has a sealing surface at its front end that is opposite to the pressing surface and in surface contact with the base end of the sealing member, and a front opening formed on the inner circumferential side of the sealing surface and communicating with the inner cavity of the syringe. The sealing component blocks the front opening and is held in place by axial pressure within the entire pressing space of the opposing portions of the pressing surface and the sealing surface. Within the pressing space, the inner circumferential side of the gap between the pressing surface and the sealing surface is the narrowest. The pressing surface is composed of an inclined surface that gradually protrudes toward the sealing surface from the outer peripheral side toward the inner peripheral side.

5. A drug delivery device, comprising: The syringe assembly according to any one of claims 1 to 4; A washer that is slidably disposed within the syringe; A plunger assembly capable of pushing the washer forward; and A drive mechanism that drives the plunger assembly.

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