Syringe barrel grip and barrel assembly and syringe

Abstract

To provide a grip for a syringe barrel capable of achieving higher sterility in a state of being attached to a syringe barrel, a barrel assembly and a syringe including such a grip for a syringe barrel.SOLUTION: A grip 30 for a syringe barrel to be attached to a syringe barrel 20 that includes a tubular body 21 and a flange 22 provided on the tubular body 21 and projecting outward, includes: a flange receiving portion 33 configured to receive the flange 22; and a side wall portion 32 extending in a distal end direction from the flange receiving portion 33 and configured to partially cover a proximal end portion of the tubular body 21 adjacent to the flange 22. The side wall portion 32 includes: a fitting portion 34 configured to be fitted to the proximal end portion of the tubular body 21; and an airflow portion 35 configured to allow a sterilization gas to flow to an outer surface of the tubular body 21 covered with the side wall portion 32.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a grip for a syringe barrel to be attached to a syringe barrel, and a barrel assembly and a syringe including such a grip for a syringe barrel.

Background Art

[0002] In some drug-filled syringes (prefilled syringes), a plunger not coupled to a gasket is used to prevent medical errors. In such a prefilled syringe, a clip (backstop) is attached to prevent the plunger from moving to the proximal end side and dropping out of the barrel (Patent Document 1).

[0003] Also, in order to facilitate the gripping and operation of a syringe, it is also known to attach a clip (grip) having a finger hook portion protruding outward to the proximal end portion of the barrel (Patent Document 2).

[0004] These clips are fitted to the outer peripheral surface of the barrel in a cylindrical fitting portion so as not to rattle or come off during the operation of the syringe, and are firmly attached to the syringe.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, particularly in ophthalmic applications, there has been a growing demand for higher sterility not only in the administered drug and the parts that come into contact with the drug, but also in the entire pre-filled syringe, including the grip.

[0007] Therefore, the inventors investigated the application of low-heat surface sterilization methods, such as hydrogen peroxide sterilization, EOG sterilization, and NO2 sterilization, to pre-filled syringes equipped with grips. These surface sterilization methods use gas (sterilization gas), and in order to achieve higher sterility, it is preferable that the sterilization gas comes into contact with a wider area of ​​the surface of the pre-filled syringe.

[0008] Therefore, the present invention provides a syringe barrel grip that can achieve higher sterility when attached to a syringe barrel, as well as a barrel assembly and syringe equipped with such a syringe barrel grip. [Means for solving the problem]

[0009] The following will achieve the above objectives: A syringe barrel grip that is attached to a syringe barrel comprising a cylindrical body, a flange protruding outward from the cylindrical body, and a base end of the cylindrical body adjacent to the flange, wherein the base end does not have a recess on its outer surface, The grip comprises a flange housing portion for housing the flange, and a side wall portion extending from the flange housing portion toward the tip and partially covering the base end of the cylindrical body adjacent to the flange. The side wall portion is provided with a fitting portion that fits with the base end of the cylindrical body and a ventilation portion for introducing sterilization gas into the outer surface of the cylindrical body covered by the side wall portion. The side wall portion is a cylindrical portion having a mounting slit at the base end of the cylindrical body of the syringe barrel, the mounting slit having an opening width smaller than the outer diameter of the cylindrical body of the syringe barrel, and in the process of attaching the grip to the syringe barrel, the mounting slit is elastically deformed and expands by the syringe barrel, and when the grip is attached to the syringe barrel, the grip is attached to the syringe barrel by an elastic restoring force. The side wall portion is formed on the inner surface of the fitting portion and has a plurality of protrusions that contact the outer surface of the syringe barrel when the grip is attached to the syringe barrel, the plurality of protrusions are arranged in a line on the same circumference of the inner surface of the fitting portion of the side wall portion, and furthermore, the plurality of protrusions are granular, conical, pyramidal, frustoconical, or frustoconical in shape, with a cross-sectional area that gradually decreases toward the inside of the syringe barrel grip. The ventilation portion is a syringe barrel grip formed by the non-contact portion between the inner surface of the side wall portion, including the portion between the plurality of protrusions formed on the inner surface of the side wall portion, and the outer surface of the cylindrical body when the grip is attached to the syringe barrel.

[0010] Furthermore, the following items will achieve the above objectives. A barrel assembly comprising a syringe barrel having a cylindrical body and a flange protruding outward from the base end of the cylindrical body, and a syringe barrel grip attached to the barrel.

[0011] Furthermore, the following items will achieve the above objectives. A syringe comprising the barrel assembly described above, a gasket slidably housed within the barrel, and a plunger for moving the gasket. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a front cross-sectional view showing an embodiment of the syringe of the present invention. [Figure 2]Figure 2 is an enlarged cross-sectional explanatory view of part A in Figure 1. [Figure 3] Figure 3 is a perspective explanatory view of the grip for the syringe barrel used in the syringe of Figure 1. [Figure 4] Figure 4 is a right side view of the grip for the syringe barrel used in the syringe of Figure 1. [Figure 5] Figure 5 is a left side view of the grip for the syringe barrel used in the syringe of Figure 1. [Figure 6] Figure 12 is an enlarged explanatory view of the B-B cross-section in Figure 1. [Figure 7] Figure 7 is a perspective explanatory view showing another embodiment of the grip for the syringe barrel of the present invention. [Figure 8] Figure 8 is an explanatory view of a syringe equipped with the grip for the syringe barrel of another embodiment of the present invention, and is an enlarged cross-sectional explanatory view corresponding to Figure 6. [Figure 9] Figure 9 is a perspective explanatory view showing the grip for the syringe barrel of another embodiment of the present invention. [Figure 10] Figure 10 is an explanatory view of a syringe equipped with the grip for the syringe barrel of Figure 9, and is an enlarged cross-sectional explanatory view corresponding to Figure 6. [Figure 11] Figure 11 is a perspective explanatory view showing the grip for the syringe barrel of another embodiment of the present invention. [Figure 12] Figure 12 is an explanatory view of a syringe equipped with the grip for the syringe barrel of Figure 11, and is an enlarged cross-sectional explanatory view corresponding to Figure 6. [Figure 13] Figure 13 is a perspective explanatory view showing the grip for the syringe barrel of another embodiment of the present invention. [Figure 14] Figure 14 is a perspective explanatory view showing the grip for the syringe barrel of another embodiment of the present invention. [Figure 15] Figure 15 is a perspective explanatory view showing the grip for the syringe barrel of another embodiment of the present invention.. [Figure 16] Figure 16 is a perspective explanatory view showing another embodiment of the grip for the syringe barrel of the present invention. [Figure 17]Figure 17 is an explanatory diagram of a syringe equipped with a grip for the syringe barrel shown in Figure 16, and is an enlarged cross-sectional explanatory diagram corresponding to Figure 6. [Figure 18] Figure 18 is an enlarged cross-sectional view illustrating section C in Figure 17. [Figure 19] Figure 19 is an enlarged cross-sectional view of the proximal end of another embodiment of the syringe of the present invention. [Figure 20] Figure 20 is a perspective view illustrating the syringe barrel grip used in the syringe shown in Figure 19. [Figure 21] Figure 21 is a perspective view illustrating a syringe barrel grip according to another embodiment of the present invention. [Modes for carrying out the invention]

[0013] A barrel assembly and syringe equipped with a syringe barrel grip according to the present invention will be described using the embodiments shown in the drawings.

[0014] In this embodiment, the right side in Figure 1 (the side where the flange 22 of the syringe barrel 20 is formed) is referred to as the base end or upper side, the left side in Figure 1 (the side where the nozzle portion 23 of the syringe barrel 20 is provided) is referred to as the tip end or lower side, and the left-right direction in Figure 1 (the axial direction of the syringe barrel 20) is referred to as the axial direction (the axial direction of the cylindrical body 21 and the side wall portion 32 of the grip 30).

[0015] The syringe 1 of the present invention comprises a barrel assembly 2 having a syringe barrel 20 (hereinafter also simply referred to as barrel 20) and a syringe barrel grip 30 (hereinafter also simply referred to as grip 30) attached to the barrel 20, a gasket 11 slidably housed inside the barrel 20, and a plunger 12 for moving the gasket 11.

[0016] The barrel 20 comprises a cylindrical body 21 and a flange 22 provided on the cylindrical body 21 that protrudes outward (in a direction perpendicular to the axial direction of the barrel 20). The tip of the barrel 20 is provided with a tip opening (nozzle portion) 23 for dispensing the drug. The barrel 20 also includes a collar 24 that encloses the base end portion of the nozzle portion 23. A barrel-side threaded portion (female threaded portion) is formed on the inner surface of the collar 24. The nozzle portion 23 is sealed by the seal cap 13, which prevents leakage of the drug 50 stored in the barrel 20 and prevents the sterile-filled drug 50 from coming into contact with the outside air.

[0017] Examples of materials that can be used to construct the barrel 20 include various resins such as polyethylene, polyolefins such as polypropylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly-(4-methylpentene-1), acrylic resin, polyesters such as acrylonitrile-butadiene-styrene copolymer and polyethylene terephthalate, cyclic polyolefin polymers, and cyclic olefin copolymers. Among these, resins such as polypropylene, cyclic polyolefin polymers, and cyclic olefin copolymers are preferred because they are easy to mold and have heat resistance. In particular, cyclic olefin polymers and cyclic olefin copolymers, which have high transparency so that the liquid medicine filled inside can be visually confirmed from the outside and have heat resistance that can withstand high-pressure steam sterilization, are preferred as the forming material for the barrel 20.

[0018] The seal cap 13 has a main body 51 having a rear end hollow portion that houses the nozzle portion 23 of the barrel 20, and a seal member 52 housed within the main body 51 and positioned at the upper end of the rear end hollow portion. Furthermore, the outer surface of the rear end hollow portion has a cap-side screw portion (male screw portion) that can be screwed into a barrel-side screw portion (female screw portion) formed on the inner surface of the collar 24.

[0019] Examples of materials for forming the seal cap 13 include various resins such as polypropylene, polyethylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly-(4-methylpentene-1), acrylic resin, acrylonitrile-butadiene-styrene copolymer, polyester such as polyethylene terephthalate, and cyclic polyolefins. Among these, polypropylene and cyclic polyolefins are preferred because they are easy to mold and have heat resistance.

[0020] As the material for forming the sealing member 52, elastic materials such as natural rubber, synthetic rubber such as isoprene rubber, butyl rubber, butadiene rubber, fluororubber, and silicone rubber, and thermoplastic elastomers such as olefin-based elastomers and styrene-based elastomers are preferred.

[0021] The gasket 11 housed within the barrel 20 is made of elastic rubber or synthetic resin. The gasket 11 comprises a roughly cylindrical main body extending with substantially the same outer diameter, and a plurality of annular ribs provided on the outer surface of the main body. The outer surfaces of the annular ribs are in liquid-tight contact with the inner surface of the barrel 20 and are slidable in a liquid-tight state.

[0022] It is preferable to use an elastic rubber (for example, butyl rubber, latex rubber, silicone rubber, etc.), a synthetic resin (for example, a styrene-based elastomer such as SBS elastomer or SEBS elastomer, or an olefin-based elastomer such as ethylene-α-olefin copolymer elastomer, etc.) as the material for forming the gasket 11.

[0023] The plunger 12 is made of a hard or semi-hard resin. In this embodiment, the plunger 12 includes a small disc-shaped gasket pressing portion 14 provided at its tip, a disc-shaped pressing operation portion 15 provided at its base end, and a shaft portion 16 with a cross-shaped cross-section that extends axially along the barrel 20 between the gasket pressing portion 14 and the pressing operation portion 15. The shaft portion 16 may be a columnar shaft. The columnar shaft may be rod-shaped, cylindrical, polygonal prism-shaped, cylindrical, or any other cylindrical shape. The plunger 12 is not connected to the gasket 11, but can contact the base end of the gasket 11 at the gasket pressing portion 14, and the pressure applied after contact allows the gasket 11 to move toward the tip.

[0024] The plunger 12 has its tip portion (gasket pressing portion 14 and a part of the tip of the shaft portion 16) housed inside the barrel 20 (cylindrical body 21). The plunger 12 is provided with a stopper portion 17 on the portion housed in the barrel 20 (shaft portion 16), which contacts the grip 30 (stopper contact portion 31), which will be described in detail later, and restricts the plunger 12 from detaching from the barrel 20. More specifically, the stopper portion 17 is disc-shaped, having an outer diameter smaller than the inner diameter of the barrel 20 (cylindrical body 21) and larger than the outer diameter of the shaft portion 16 of the plunger 12. It is preferable to use a rigid or semi-rigid resin such as high-density polyethylene, polypropylene, polystyrene, or polyethylene terephthalate as the constituent material of the plunger 12.

[0025] In syringe 1, the drug (medicinal solution) 50 is stored (filled) inside the barrel 20 (in the space formed between the seal cap 13 and the gasket 11). The drugs to be stored are not particularly limited, but examples include vitamins, sugars, electrolytes, organic acids, minerals, and lipid emulsions, mainly as nutritional supplements, as well as amino acids, proteins, and organ preparations. Furthermore, examples include central nervous system drugs such as general anesthetics, antipyretics, analgesics, and cold medicines, peripheral nervous system drugs such as local anesthetics and muscle relaxants, sensory organ drugs such as ophthalmic agents, cardiovascular drugs, respiratory drugs, digestive drugs, urinary tract, genitourinary tract, and anal drugs, metabolic drugs such as hormones, antibiotics, and diabetes drugs, antitumor drugs, anti-allergic drugs, biological preparations such as antibacterial and antiviral agents, and compounding agents such as distilled water and physiological saline. In addition, examples include vaccines, mainly as preventive agents, and contrast agents, mainly as diagnostic agents. The drugs exemplified here are mostly composed of synthetic low-molecular-weight compounds, synthetic medium-molecular-weight compounds, biopharmaceuticals such as polypeptide and protein preparations, and bio-derived pharmaceuticals such as blood products. However, these substances can be used as drugs regardless of the applications described above. Substances that fall under molecularly targeted drugs, such as antibodies, can also be used as drugs. From the standpoint of ease of use, even if these drugs are available in solid dosage forms such as powders or granules in addition to liquid formulations, the liquid formulation is preferable.

[0026] Furthermore, as drug 50, ophthalmic drugs that can be administered by puncture can be used. Specific target diseases for which such ophthalmic drugs are used include choroidal neovascularization, age-related macular degeneration (both exudative and atrophic types), macular edema secondary to retinal vein occlusion (RVO) (including both branch retinal vein occlusion (bRVO) and central retinal vein occlusion (cRVO)), choroidal neovascularization secondary to pathological myopia (PM), diabetic macular edema (DME), diabetic retinopathy, and proliferative retinopathy. Examples of drugs used include ranibizumab [trade name Lucentis®], bevacizumab [trade name Avastin®], aflibercept [trade name Eylea®], and conbercept, also known as VEGF-TrapEye (Aflibercept intravitreal injection), which are anti-VEGF antibodies used to treat age-related macular degeneration.

[0027] The structure of the syringe barrel grip 30 of the present invention will be described in the examples shown in Figures 1 to 6. The syringe barrel grip 30 in this embodiment includes a flange housing portion 33 for housing the flange 22, and a side wall portion 32 that extends from the flange housing portion 33 toward the tip and partially covers the base end of the cylindrical body 21 adjacent to the flange 22. The side wall portion 32 includes a fitting portion 34 that fits with the base end of the cylindrical body 21, and a ventilation portion (opening 35) for introducing sterilization gas into the outer surface of the cylindrical body 21 covered by the side wall portion 32. In this embodiment, the side wall portion 32 is a cylindrical portion (a short, approximately semi-cylindrical portion) having an insertion opening at the base end of the cylindrical body 21.

[0028] Specifically, the flange housing portion 33 of the grip 30 constitutes the base end portion of the grip 30. A pair of finger rests 36, 36 are formed in the flange housing portion 33 so as to protrude outward (in a direction perpendicular to the axial direction of the barrel 20). The pair of finger rests 36, 36 protrude in opposite directions from each other in a direction perpendicular to the axial direction of the barrel 20. The pair of finger rests 36, 36 extend outward beyond the flange 22 of the barrel 20. The pair of finger rests 36, 36 can be used by the operator to rest their fingers on when operating the syringe 1.

[0029] The flange housing portion 33 comprises an upper plate portion 37 and a lower plate portion 38 that sandwich the flange 22. As shown in Figure 4, a slit (opening) 39 is formed in the upper plate portion 37 of the flange housing portion 33. The slit 39 is formed so that the shaft portion 16 of the plunger 12 can enter. A part of the inner edge of the slit 39 forms a stopper contact portion 31 that abuts against the stopper portion 17 of the plunger 12. The stopper contact portion 31 has an inner shape (inner diameter) that is larger than the outer shape (outer diameter) of the shaft portion 16 of the plunger 12 and smaller than the outer shape (outer diameter) of the stopper portion 17 of the plunger 12. As a result, the slit 39 allows the shaft portion 16 of the plunger 12 to pass through the stopper contact portion 31, while abutting against the stopper portion 17 of the plunger 12. The plunger 12, housed in the barrel 20, is prevented from detaching from the barrel 20 by contacting the stopper contact portion 31 of the grip 30 at the stopper portion 17. In this embodiment, the grip comprises an upper plate portion 37 and a lower plate portion 38, as described above, and a slit (opening) 39 is formed in the upper plate portion 37 of the flange housing portion 33. In this embodiment, the flange housing portion 33 houses the flange 22 from the side. The flange housing portion 33 also houses the flange 22 by sandwiching it between the upper plate portion 37 and the lower plate portion 38.

[0030] As shown in Figure 5, a slit (opening) 40 is formed in the lower plate portion 38 of the flange housing portion 33. The inner edge of the slit 40 is integrally connected to the side wall portion 32, which will be described in detail later.

[0031] As shown in Figure 2, the gap between the upper plate portion 37 and the lower plate portion 38 of the flange housing 33 is slightly larger than the thickness of the flange 22 of the barrel 20. This creates a small gap between the upper surface (base end side) and / or lower surface (tip end side) of the flange 22 and the upper plate portion 37 and / or lower plate portion 38 of the flange housing 33, through which sterilization gas can flow.

[0032] The grip 30 includes a side wall portion 32 that extends from the flange housing portion 33 toward the tip, specifically toward the axial tip. At its base end, the side wall portion 32 is integrally connected to the inner edge of the slit 40 of the lower plate portion 38 of the flange housing portion 33. The side wall portion 32 has a mounting opening (mounting slit) 41 that extends along its entire length in the axial direction, and in the portion other than the opening 41, it partially covers the base end of the barrel 20 (cylindrical body 21). The side wall portion 32 extends in the circumferential direction, except for the opening 41. In other words, the side wall portion 32 is formed by cutting out a part of the circumferential direction of a cylindrical member as a mounting slit 41, and is formed so that the cross section formed by a plane perpendicular to the axial direction is C-shaped. In this embodiment, the side wall portion 32 is a cylindrical portion (a short, approximately semi-cylindrical portion) having an opening for insertion of the base end of the cylindrical body 21.

[0033] When the side wall portion 32 is in its natural state without elastic deformation, the opening width of the mounting slit 41 is smaller than the outer diameter of the cylindrical body 21 of the barrel 20. When attaching the grip 30 to the barrel 20, The flange 22 enters the flange housing 33 from its side, and also, The mounting slit 41 is elastically deformed and widened by the barrel 20. When the grip 30 is attached to the barrel 20, the mounting slit 41 returns to its original opening width due to the elastic restoring force. As a result, the grip 30 is firmly attached to the barrel 20. Furthermore, the flange 22 is housed in the flange housing section 33.

[0034] In the side wall portion 32, the portion that directly contacts the outer surface of the cylindrical body 21 of the barrel 20 forms a fitting portion 34. In other words, the fitting portion 34 refers to the inner surface of the side wall portion 32 that directly contacts the outer surface of the cylindrical body 21, and a part of the side wall portion 32 corresponding to such an inner surface. In this embodiment, the portion of the side wall portion 32 in which the opening 35 (described in detail later) is not formed, and its inner surface, form the fitting portion 34.

[0035] Multiple openings 35 are formed in the side wall portion 32. These multiple openings 35 constitute a ventilation section. In the grip 30, the ventilation section is formed by multiple openings 35 formed in the side wall portion 32. In this embodiment, six rectangular, window-shaped openings 35 are formed in the side wall portion 32. Each opening 35 penetrates the side wall portion 32 radially (in a direction perpendicular to the axial direction). In the portion where each opening 35 is formed, the outer surface of the cylindrical body 21 of the barrel 20 is exposed to the outside. Furthermore, when attaching the syringe barrel grip 30 to the syringe barrel 20, the contact area between the side wall portion 32 of the syringe barrel grip 30 and the base end of the cylindrical body 21 is preferably 40% or less of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 32. This configuration ensures reliable sterilization.

[0036] In this embodiment, as shown in Figure 6, the side wall portion 32 (fitting portion 34) in which the opening 35 is not formed is formed to taper inward in a cross-section of a plane perpendicular to the axial direction. Therefore, the contact area between the fitting portion 34 and the barrel 20 is small. In the embodiments shown in Figures 1 to 6, the contact area between the side wall portion 32 of the syringe barrel grip 30 and the base end of the cylindrical body 21 is 50% or less of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 32.

[0037] In the side wall portion 32, it is preferable that 5 to 10 such rectangular openings 35 are formed. Furthermore, the area of ​​the portion (fitting portion 34) where the inner surface of the side wall portion 32 and the outer surface of the cylindrical body 21 come into contact is preferably 10 to 50% of the area of ​​the entire inner surface of the side wall portion 32 when no openings 35 are formed, and is particularly preferably 10 to 40%. In addition, the axial length of the side wall portion 32 is preferably 0.17 to 3.4 mm, and is particularly preferably 0.34 to 1.7 mm.

[0038] It is desirable that none of the openings 35 open at the tip end (end face) of the side wall portion 32. This maintains the strength of the tip end of the side wall portion 32, reduces the area of ​​the fitting portion 34, and allows the grip 30 to be firmly attached to the barrel 20, thereby suppressing rattling of the grip 30.

[0039] It is preferable to use rigid or semi-rigid resins such as polyethylene, polyolefins such as polypropylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly-(4-methylpentene-1), acrylic resin, polyester such as acrylonitrile-butadiene-styrene copolymer and polyethylene terephthalate, cyclic polyolefin polymers, and cyclic olefin copolymers as constituent materials for the grip 30.

[0040] Furthermore, the material used for the grip 30 may have a higher coefficient of thermal expansion (linear thermal expansion) than the material used for the barrel 20. This allows the inner surface (inner diameter) of the grip 30 to expand more than the outer surface (outer diameter) of the barrel 20 (cylindrical body 21) when the syringe 1 is heated during the surface sterilization (gas sterilization) process described later. This creates a small gap between a part of the inner surface (fitting portion 34) of the grip 30 and the outer surface of the cylindrical body 21, into which sterilization gas can enter, potentially improving the sterilization of the syringe 1.

[0041] The manufacturing method (manufacturing process) for syringe 1 will be explained below. First, the barrel 20 is sterilized with the seal cap 13 attached to the nozzle portion 23 of the barrel 20. The sterilization method used at this time is not particularly limited, and for example, autoclave sterilization (high-temperature steam sterilization) using an autoclave, surface sterilization using a sterilizing gas such as hydrogen peroxide or EOG (gas sterilization), or radiation sterilization using radiation such as gamma rays or electron radiation can be used. Here, as an example, autoclave sterilization is performed.

[0042] Next, under sterile conditions, the sterilized barrel 20 is aseptically filled with the drug 50, which has been pre-sterilized (e.g., by filtration sterilization). In this embodiment, the drug 50 used for ophthalmic purposes is relatively sensitive to heat. After filling with the drug 50, the gasket 11 is inserted into the barrel 20. The insertion (sealing) of the gasket 11 can be performed under reduced pressure.

[0043] Next, the tip portion of the plunger 12 is stored inside the barrel 20, and the grip 30 is attached to the barrel 20. Note that this operation can also be performed in a non-sterile environment.

[0044] Next, the syringe 1 with the grip 30 attached to the barrel 20 is sterilized. In this embodiment, since the drug 50 stored in the barrel 20 is an ophthalmic drug that is relatively sensitive to heat, surface sterilization (NO2 sterilization) using a sterilizing gas (in this case, NO2 (nitrogen dioxide)) is performed.

[0045] As described above, syringe 1 can be manufactured aseptically. In this embodiment, the grip 30 (side wall portion 32) has multiple (in this case, six) openings 35. Sterilizing gas comes into contact with the outer surface of the base end of the barrel 20 (cylindrical body 21), which is partially covered by the side wall portion 32, through each opening 35. This ensures more reliable sterilization of the syringe 1, which includes the barrel 20 (barrel assembly 2) to which the grip 30 is attached.

[0046] In this embodiment, the side wall portion 32 (fitting portion 34) where the opening 35 is not formed is formed to taper inward in a cross-section of a plane perpendicular to the axial direction. This allows the sterilization gas to come into contact with a wider area of ​​the outer surface of the barrel 20 (cylindrical body 21) and the inner surface of the grip 30 while maintaining the strength of the fitting portion 34. The shape of the fitting portion 34 in the side wall portion 32 is appropriately set by molding conditions, etc.

[0047] Furthermore, the sterilizing gas can enter the gap that inevitably forms between the inner surface of the fitting portion 34 and the outer surface of the cylindrical body 21 from the peripheral portion of the fitting portion 34 of the side wall portion 32. In the grip 30 of this embodiment, since a plurality of openings 35 are formed in the side wall portion 32, the sterilizing gas can also enter the space between the inner surface of the fitting portion 34 and the outer surface of the cylindrical body 21 from the peripheral portions of these openings 35. As a result, the sterilizing gas can come into contact with a wider area of ​​the outer surface of the barrel 20 (cylindrical body 21) and the inner surface of the grip 30, thus enabling more reliable sterilization. When considering this effect, it is also effective to form a large number of relatively small openings in order to increase the peripheral length of the openings (the sum of the lengths of the peripheral portions of the multiple openings) relative to the opening area (the sum of the areas of the multiple openings). Specifically, a large number of through holes can be considered as relatively small openings.

[0048] The shape of the opening formed in the side wall as a ventilation section is not limited to the rectangular hole shape described above, but may also be circular, triangular, or other polygonal hole (window) shapes. In the grip 30a shown in Figure 7, multiple triangular hole-shaped openings 35a are formed in the side wall 32a in an alternating pattern. In this case, the structure of the part of the side wall 32a other than the part in which the openings 35a are formed becomes a so-called truss structure. As a result, the strength of the side wall 32a can be increased compared to the case in which a rectangular hole shape is formed, provided that the opening area is the same.

[0049] Furthermore, when the openings formed in the side wall are formed by triangular-shaped openings 35a with a truss structure for the side wall 32a, it is preferable that 6 to 20 openings 35a are formed. The contact area between the side wall 32a of the syringe barrel grip 30a and the base end of the cylindrical body 21 is preferably 10 to 40% of the area of ​​the base end of the cylindrical body 21 covered by the side wall 32a. In other words, the contact area between the side wall 32a of the syringe barrel grip and the base end of the cylindrical body 21 when attached to the syringe barrel (the area of ​​the part where the inner surface of the side wall 32a and the outer surface of the cylindrical body 21 come into contact) is preferably 10 to 40% of the area of ​​the base end of the cylindrical body 21 covered by the side wall 32a (the area of ​​the entire inner surface of the side wall 32a when no openings are formed).

[0050] Furthermore, as shown in Figure 8, the grip 30b may be formed such that the inner surface of the portion of the side wall 32b where the openings 35b are not formed (excluding the axial ends, in other words, the middle portion of the fitting portion) is separated from the outer surface of the cylindrical body 21. This allows the sterilization gas to come into contact with a wider area of ​​the outer surface of the barrel 20 (cylindrical body 21) and the inner surface of the grip 30b while maintaining the attachment force (fitting force) of the grip 3b to the cylindrical body 21 at both axial ends of the side wall 32b (fitting portion 34b).

[0051] Figures 9 to 18 show other embodiments of the barrel assembly and syringe equipped with the syringe barrel grip of the present invention, respectively. In these embodiments, the shape of the ventilation portion differs from that of the grip 30 in the above-described embodiment (syringe 1 and barrel assembly 2). In these embodiments, unless otherwise specified, the same names and reference numerals are used for components common to the above-described embodiment and other embodiments, and detailed descriptions are omitted.

[0052] In the syringe and barrel assembly of the present invention shown in Figures 9 to 18, the grip has a ventilation portion provided on the inner surface of the side wall, and is formed by a non-contact portion between the inner surface of the side wall and the outer surface of the cylindrical body. Such a ventilation portion reduces the area of ​​the contact portion (fitting portion) between the inner surface of the side wall and the outer surface of the cylindrical body, while increasing the contact area between the sterilizing gas and the inner surface of the side wall and the outer surface of the cylindrical body covered by the side wall.

[0053] In the syringe 7 and barrel assembly 8 of the present invention shown in Figures 9 and 10, the ventilation portion of the syringe barrel grip 60 (hereinafter also simply referred to as grip 60) is formed by a plurality of recesses 65 formed on the inner surface of the side wall portion 62.

[0054] Specifically, the inner surface of the side wall portion 62 of the grip 60 has a roughly rectangular cross-section formed by planes perpendicular to the axial direction, and multiple (in this case, 10) recesses 65 extending in the axial direction are formed therein. Each recess 65 is formed along the entire axial length of the side wall portion 62. In other words, each recess 65 is open at both axial ends of the side wall portion 62. The inner surface of the side wall portion 62 and the outer surface of the cylindrical body 21 are not in contact in the portions where the recesses 65 are formed.

[0055] In this embodiment, the portion of the side wall 62 where the recess 65 is not formed, and its inner surface, form a fitting portion 64 that fits with the base end of the cylindrical body 21. The cross-section of the fitting portion 64, formed by planes perpendicular to the axial direction, is substantially rectangular in shape.

[0056] In this embodiment, the grip 60 (side wall portion 62) has a plurality (in this case, 10) recesses 65 formed therein, and sterilizing gas comes into contact with the inner surface of the side wall portion 62 and the outer surface of the base end of the barrel 20 (cylindrical body 21) which is partially covered by the side wall portion 62 through each recess 65. This makes the sterilization of the syringe 7, which has the barrel 20 (barrel assembly 8) to which the grip 60 is attached, more reliable. The number of recesses 65 (fitting portion 64) is preferably 3 to 30, and particularly preferably 10 to 20.

[0057] Furthermore, in this embodiment, the recess 65 formed in the grip 60 (side wall portion 62) is open at both axial ends of the side wall portion 62, making it easier for sterilization gas to flow (enter or pass through) within the recess 65. Also, in this embodiment, the width (circumferential dimension) of the recess 65 formed in the grip 60 (side wall portion 62) is wider at the tip of the side wall portion 62 (lower end of the side wall portion 62 in Figure 9) and narrows towards the base end. This facilitates the entry of sterilization gas. In addition, the width (circumferential dimension) of the fitting portion 64 formed in the grip 60 (side wall portion 62) is narrower at the tip of the side wall portion 62 (lower end of the side wall portion 62 in Figure 9) and widens towards the base end. This ensures secure holding of the outer cylinder at the base end of the side wall portion 62.

[0058] In the side wall portion 62, it is preferable that 3 to 10 recesses 65 are formed on the inner surface of the side wall portion 62. Furthermore, it is preferable that the contact area between the side wall portion 62 of the syringe barrel grip 60 and the base end of the cylindrical body 21 is 0.1 to 40% of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 62. In other words, when attached to the syringe barrel, the contact area between the side wall portion 62 of the syringe barrel grip and the base end of the cylindrical body 21 (the area of ​​the portion where the inner surface of the side wall portion 62 and the outer surface of the cylindrical body 21 come into contact) is preferably 0.1 to 40% of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 62 (the area of ​​the entire inner surface of the side wall portion 62 when no recesses are formed). Furthermore, the grip 60g shown in Figure 21 has the same configuration as the grip 60 shown in Figure 9. Compared to the grip 60g, the number of recesses 65 formed in the side wall portion 62 is the same (10), but the width (circumferential dimension) is larger (in other words, the width of the fitting portion 64 is smaller). As a result, in the grip 60g shown in Figure 21, the contact area between the side wall portion 62 of the syringe barrel grip 60g and the base end of the cylindrical body 21 is smaller than that of the grip 60 shown in Figure 9, and is 30% of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 62. Furthermore, in the grip 60g of the embodiment shown in Figure 21, the width of the recess 65 formed in the grip 60g (side wall portion 62) is wider at the tip of the side wall portion 62 (the lower end of the side wall portion 62 in Figure 21) and narrows towards the base end. This facilitates the entry of sterilization gas. In addition, the width of the fitting portion 64 formed in the grip 60g (side wall portion 62) is narrower at the tip of the side wall portion 62 (the lower end of the side wall portion 62 in Figure 21) and widens towards the base end. This ensures secure holding of the outer cylinder at the base end of the side wall portion 62.

[0059] Furthermore, the cross-sectional shape of the recess formed in the side wall as a ventilation section, determined by a plane perpendicular to the axial direction, is not limited to the approximately rectangular shape described above, but may be various shapes such as a triangle, trapezoid, other polygons, or crescent shape. It is desirable that the recess be formed such that the cross-section determined by a plane perpendicular to the axial direction is trapezoidal or triangular in shape, so as to reduce the contact area between the inner surface of the side wall (fitting section) and the outer surface of the cylindrical body (so that the shape of the fitting section narrows radially inward in the cross-section determined by a plane perpendicular to the axial direction). In addition, it is preferable that the recess forming the ventilation section extends parallel to the axial direction, but it may also extend diagonally with respect to the axis or in a spiral shape.

[0060] Figures 11 and 12 show another embodiment of the barrel assembly and syringe equipped with the syringe barrel grip of the present invention. In this embodiment, the shape of the ventilation portion differs from that of the grip 60 in the above-described embodiment (syringe 7 and barrel assembly 8).

[0061] In the syringe 7a and the grip 60a of the barrel assembly 8a of this embodiment, the ventilation portion is formed by the space between a plurality of protrusions 66 (the space between the protrusions 67) formed on the inner surface of the side wall portion 62a.

[0062] Specifically, multiple (in this case, 11) protrusions 66 projecting radially inward are formed on the inner surface of the side wall portion 62a of the grip 60a. The protrusions 66 are approximately semicircular in shape when viewed from the radially inward side of the side wall portion 62a (radial view), and are formed on the inner surface of the base end (upper end) of the side wall portion 62a, arranged on the same circumference. The upper surface of the protrusions 66 is approximately flush with the upper surface of the lower plate portion 38. In this embodiment, the inner surface of the protrusions 66 and the portion of the side wall portion 62a on which the protrusions 66 are formed serve as a fitting portion 64a that fits with the base end of the cylindrical body 21. The inner surface of the portion of the side wall portion 62a on which the protrusions 66 are not formed (the portion between protrusions 67) is not in contact with the outer surface of the cylindrical body 21. In the grip 60a, the portion between protrusions 67, which is a non-contact portion with the outer surface of the cylindrical body 21, is formed on the inner surface of the side wall portion 62a as a ventilation portion.

[0063] In this embodiment, the grip 60a (side wall portion 62a) has a plurality (11 in this case) of protrusions 66 formed thereon. Sterilizing gas comes into contact with the inner surface of the side wall portion 62a and the outer surface of the base end of the barrel 20 (cylindrical body 21) partially covered by the side wall portion 62a through the non-contact inter-protrusion portions 67 formed between these protrusions 66 and the outer surface of the base end of the barrel 20 (cylindrical body 21). This further enhances the sterilization of the syringe 7a, which has a barrel 20 (barrel assembly 8a) to which the grip 60a is attached.

[0064] Furthermore, since the inter-projection portion 67 formed on the grip 60a (side wall portion 62a) is open to the outside at both axial and circumferential ends of the side wall portion 62a, sterilization gas can easily flow (enter or pass through) within the inter-projection portion 67.

[0065] In the side wall portion 62a, it is preferable that 3 to 20 protrusions 66 are formed on the inner surface of the side wall portion 62a. Furthermore, it is preferable that the contact area between the side wall portion 62a of the syringe barrel grip 60a and the base end of the cylindrical body 21 is 0.1 to 40% of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 62a. In other words, it is preferable that the area of ​​the portion (fitting portion 64a) where the inner surface of the side wall portion 62a (the inner surface of the multiple protrusions 66) and the outer surface of the cylindrical body 21 come into contact is 0.1 to 40% of the area where the inner surface of the side wall portion 62a and the outer surface of the cylindrical body 21 come into contact when no protrusions are formed. In this embodiment, the contact area between the side wall portion 62a of the syringe barrel grip 60a and the base end of the cylindrical body 21 is 14% of the area of ​​the base end of the cylindrical body 21 covered by the side wall portion 62a.

[0066] Furthermore, the shape of the projection formed on the side wall (in radial view) is not limited to the semicircular shape exemplified, but may be, for example, a rectangle or other polygonal shape. It may also be a cone shape, a triangular pyramidal shape, other polygonal pyramidal shapes, a frustoconical shape, a triangular frustoconical shape, or other polygonal frustoconical shapes, with the cross-sectional area gradually decreasing inward.

[0067] Furthermore, the shape of the protrusions formed on the grip (side wall portion) may be as shown in Figure 13. In the grip 60b of the embodiment shown in Figure 13, granular protrusions 66a are formed on the inner surface of the grip (side wall portion). This makes it possible to make the contact area (area of ​​the fitting portion 64a) between the protrusions 66a (inner surface of the side wall portion 62a) and the outer surface of the cylindrical body 21 extremely small. Furthermore, the shape of the projection formed on the grip (side wall portion) may be as shown in Figure 14. In the embodiment of the grip 60c shown in Figure 14, a projection 66b in the shape of a substantially triangular pyramid (subtle tetrahedron) is formed on the grip 60c at the base end inner peripheral edge of the side wall portion 62a. This also makes it possible to make the contact area (area of ​​the fitting portion 64a) between the projection 66b (inner surface of the side wall portion 62a) and the outer surface of the cylindrical body 21 extremely small.

[0068] Furthermore, the multiple protrusions are not limited to being provided on the same circumference as in the example, but may be provided at any position. Also, for example, they may be provided in two or more rows on a circumference with different axial positions, or in two rows and alternating (staggered) positions. The grip 60d shown in Figure 15 is provided with two rows of protrusions 66a on a circumference with different axial positions (at the base end and tip end of the side wall portion 62a). In the grip 60d of this embodiment, as shown in Figure 15, the multiple protrusions are arranged to form a first row on the circumference of the inner surface of the tip side of the side wall portion 62a and a second row on the circumference of the inner surface of the base end of the side wall portion 62a.

[0069] Figures 16 to 18 show another embodiment of the barrel assembly and syringe equipped with the syringe barrel grip of the present invention. In this embodiment, the shape of the ventilation portion differs from that of the grip 60 in the above-described embodiment (syringes 7, 7a and barrel assemblies 8, 8a).

[0070] In this embodiment, the grip 60e in the syringe 7b and barrel assembly 8b is formed by a roughened surface 68 formed on the inner surface of the side wall 62b.

[0071] Specifically, a rough surface 68 is formed on the entire inner surface of the side wall portion 62b of the grip 60e (shown by dot hatching in Figure 16). The rough surface 68 is formed by known surface treatments such as texturing or shot blasting. In this embodiment, the mold (injection molding mold) for molding the grip 60e is pre-roughened, and the rough surface 68 is formed by embossing (texturing) which is transferred to the mold.

[0072] Preferably, the roughened surface 68 formed on the inner surface of the side wall portion 62b is formed so that sterilization gas can enter when the grip 60e is attached to the barrel 20 (cylindrical body 21). Regarding the degree of roughness in the roughened portion 68, it is preferable that the embossed portion forms a plurality of intersecting, fine groove-like recesses, and the depth of the recesses is approximately 5 to 1000 μm. As a result, a non-contact area is formed between the inner surface of the side wall portion 62b and the outer surface of the cylindrical body 21 in the roughened portion 68. Figure 18 schematically shows (with the irregularities of the roughened portion 68 exaggerated) that a portion 69 into which sterilization gas can enter is formed in the roughened portion 68.

[0073] In this embodiment, the grip 60e (side wall portion 62b) has a roughened surface portion 68 formed thereon, and sterilizing gas comes into contact with the inner surface of the side wall portion 62b and the outer surface of the base end of the barrel 20 (cylindrical body 21) that is partially covered by the side wall portion 62 through the roughened surface portion 68. This makes the sterilization of the syringe 7b, which has the barrel 20 (barrel assembly 8b) to which the grip 60e is attached, more reliable.

[0074] Figures 19 and 20 show another embodiment of the barrel assembly and syringe equipped with the syringe barrel grip of the present invention. Figure 19 is an enlarged cross-sectional view of the base end of another embodiment of the syringe of the present invention. Figure 20 is a perspective view illustrating the syringe barrel grip used in the syringe of Figure 19. Syringe 7c of this embodiment is equipped with a grip 60f that has a different shape of ventilation portion compared to the grip 60 of the above-described embodiment (syringe 7 and barrel assembly 8).

[0075] In this embodiment, the grip 60f of the syringe 7c and barrel assembly 8c has a ventilation portion 70 formed by a tapered portion on the inner surface of the side wall portion 62c. The fitting portion 64c is formed by the small diameter portion (small inner diameter) at the base end of the tapered portion. The side wall portion 62c is a tapered portion whose inner diameter widens towards the tip, and the outer diameter is almost the same throughout. Therefore, the side wall portion 62c becomes thinner towards the tip. The base end of the barrel 20 (cylindrical body 21), which is partially covered by the side wall portion 62c, does not come into contact with the side wall portion 62c except for the fitting portion 64c. Therefore, the outer surface of the barrel 20 and the tapered portion (ventilation portion 70) of the side wall portion 62c in that portion come into contact with the sterilizing gas. This further enhances the sterilization of the syringe 7c equipped with the barrel 20 (barrel assembly 8c) to which the grip 60f is attached.

[0076] In this embodiment, in order to further reduce the area of ​​the fitting portion 64c and improve sterilization, as shown in Figure 19, the inner surface (tapered portion 70) of the side wall portion 62c is inclined to be spaced apart from the outer surface of the cylindrical body 21 at a predetermined angle (θ) toward the tip. The area of ​​the portion (fitting portion 64c) where the inner surface of the side wall portion 62c and the outer surface of the cylindrical body 21 come into contact is preferably 0.1 to 50%, and particularly preferably 10 to 40%, compared to the case where the inner surface of the side wall portion 62c is not tapered. Furthermore, the taper angle (θ in Figure 19) of the side wall portion 62c is preferably 0.2 degrees or more, and particularly preferably 0.5 degrees or more. The fitting portion 64c may also have a recess or groove that extends in the axial direction and connects the ventilation portion 70 and the flange housing portion 33. Providing such a recess or groove improves the flow of sterilization gas.

[0077] Furthermore, the inner surface of the side wall portion, which serves as the tapered section, is not limited to an inclined surface that is linearly spaced apart from the outer surface of the cylindrical body 21, as in this embodiment. For example, it may be a curved surface that is convex inward or a curved surface that is concave outward. Also, the tapered section may be provided from the axial central portion of the side wall portion toward the tip.

[0078] Furthermore, in the syringe barrel grip of the present invention, and in barrel assemblies and syringes equipped with such syringe barrel grips, the ventilation portion of the grip is not limited to forming only one of the above-mentioned openings and non-contact portions (recesses, inter-projection portions, roughened portions, and tapered portions), but may be formed by appropriately combining these configurations. [Industrial applicability]

[0079] The syringe barrel grip of the present invention is as follows: (1) A syringe barrel grip that is attached to a syringe barrel having a cylindrical body and a flange that protrudes outward provided on the cylindrical body, The grip comprises a flange housing portion for housing the flange, and a side wall portion extending from the flange housing portion toward the tip and partially covering the base end of the cylindrical body adjacent to the flange. The side wall portion is a grip for a syringe barrel, comprising a fitting portion that engages with the base end of the cylindrical body and a vent portion for introducing sterilizing gas into the outer surface of the cylindrical body covered by the side wall portion.

[0080] The syringe barrel grip described above allows for contact of sterilizing gas with a wider area of ​​the outer surface of the syringe barrel, resulting in more reliable sterilization of the syringe barrel with the grip attached.

[0081] Furthermore, the above embodiment may also be as follows: (2) The syringe barrel grip according to (1) above, wherein the side wall portion is a cylindrical portion having an insertion opening at the base end of the cylindrical body. (3) The syringe barrel grip according to (1) or (2) above, wherein the ventilation portion is formed by a plurality of openings formed in the side wall. (4) The syringe barrel grip according to (1) or (2) above, wherein the ventilation portion is provided on the inner surface of the side wall portion and is formed by a non-contact portion between the inner surface of the side wall portion and the outer surface of the cylindrical body. (5) The syringe barrel grip according to (4) above, wherein the ventilation portion reduces the contact area between the inner surface of the side wall and the outer surface of the cylindrical body, and increases the contact area between the sterilizing gas and the inner surface of the side wall and the outer surface of the cylindrical body covered by the side wall. (6) The syringe barrel grip according to (4) or (5) above, wherein the ventilation portion is formed by a plurality of recesses formed on the inner surface of the side wall portion. (7) The syringe barrel grip according to (4) or (5) above, wherein the ventilation portion is formed by the space between a plurality of protrusions formed on the inner surface of the side wall portion. (8) The syringe barrel grip according to (4) or (5) above, wherein the ventilation portion is formed by a roughened surface formed on the inner surface of the side wall portion. (9) The syringe barrel grip according to (4) or (5) above, wherein the ventilation portion is formed by a tapered portion formed on the inner surface of the side wall portion. (10) The syringe barrel grip according to any one of (1) to (9) above, wherein the contact area between the side wall portion of the syringe barrel grip and the base end portion of the cylindrical body when attached to the syringe barrel is 40% or less of the area of ​​the base end portion of the cylindrical body covered by the side wall portion.

[0082] The barrel assembly of the present invention is as follows: (11) A barrel assembly comprising a syringe barrel having a cylindrical body and a flange protruding outward provided at the base end of the cylindrical body, and a syringe barrel grip as described in any of (1) to (10) above, attached to the barrel.

[0083] In the barrel assembly described above, a wider area of ​​the outer surface of the syringe barrel can be exposed to sterilizing gas, resulting in more reliable sterilization of the barrel assembly.

[0084] The syringe of the present invention is as follows: (12) A syringe comprising the barrel assembly described in (11) above, a gasket slidably housed within the barrel, and a plunger for moving the gasket.

[0085] With the syringe described above, a wider area of ​​the outer surface of the syringe barrel can be exposed to sterile gas, resulting in more reliable sterilization of the syringe.

[0086] Furthermore, the above embodiment may also be as follows: (13) The syringe according to (12) above, wherein the plunger has a tip portion housed in the barrel, and the plunger has a stopper portion provided in the portion housed in the barrel, which contacts the grip and restricts the plunger from detaching from the barrel. (14) The syringe according to (12) or (13) above, wherein the plunger is not connected to the gasket and has a gasket pressing portion at its tip that contacts the base end of the gasket. (15) A syringe according to any one of (12) to (14) above, wherein the drug is stored in the barrel.

Claims

1. A syringe barrel grip that is attached to a syringe barrel comprising a cylindrical body, a flange protruding outward from the cylindrical body, and a base end of the cylindrical body adjacent to the flange, wherein the base end does not have a recess on its outer surface, The grip comprises a flange housing portion for housing the flange, and a side wall portion extending from the flange housing portion toward the tip and partially covering the base end of the cylindrical body adjacent to the flange. The side wall portion is provided with a fitting portion that fits with the base end of the cylindrical body and a ventilation portion for introducing sterilization gas into the outer surface of the cylindrical body covered by the side wall portion. The side wall portion is a cylindrical portion having a mounting slit at the base end of the cylindrical body of the syringe barrel, the mounting slit having an opening width smaller than the outer diameter of the cylindrical body of the syringe barrel, and in the process of attaching the grip to the syringe barrel, the mounting slit is elastically deformed and expands by the syringe barrel, and when the grip is attached to the syringe barrel, the grip is attached to the syringe barrel by an elastic restoring force. The side wall portion is formed on the inner surface of the fitting portion and has a plurality of protrusions that contact the outer surface of the syringe barrel when the grip is attached to the syringe barrel, the plurality of protrusions are arranged in a line on the same circumference of the inner surface of the fitting portion of the side wall portion, and furthermore, the plurality of protrusions are granular, conical, pyramidal, frustoconical, or frustoconical in shape, with a cross-sectional area that gradually decreases toward the inside of the syringe barrel grip. The ventilation portion is formed by a non-contact portion between the inner surface of the side wall portion and the outer surface of the cylindrical body when the grip is attached to the syringe barrel, including the portion between the plurality of protrusions formed on the inner surface of the side wall portion.

2. The syringe barrel grip according to claim 1, wherein the plurality of protrusions are provided in multiple rows on a circumference where the axial positions of the side wall portion are different.

3. The syringe barrel grip according to claim 1, wherein the plurality of protrusions form a first row arranged on the same circumference on the inner surface of the tip side of the side wall and a second row arranged on the same circumference on the inner surface of the base end of the side wall.

4. The syringe barrel grip according to claim 1, wherein the fitting portion comprises a base end portion on the flange housing side and a tip portion, and the plurality of protrusions are arranged on the same circumference of the inner surface of the base end portion of the fitting portion on the side wall.

5. The syringe barrel grip according to any one of claims 1 to 4, wherein the portion between the protrusions formed on the side wall is open to the outside at both axial ends of the side wall.

6. The fitting portion of the side wall that fits with the base end of the cylindrical body is formed by the projection and the side wall portion on which the projection is formed, according to any one of claims 1 to 5.

7. The syringe barrel grip according to any one of claims 1 to 6, wherein the contact area between the side wall portion of the syringe barrel grip and the base end portion of the cylindrical body when attached to the syringe barrel is 40% or less of the area of ​​the base end portion of the cylindrical body covered by the side wall portion.

8. A barrel assembly comprising a cylindrical body, a flange protruding outward from the cylindrical body, a syringe barrel having a base end of the cylindrical body adjacent to the flange and having no recess on the outer surface of the base end, and a syringe barrel grip according to any one of claims 1 to 7 attached to the syringe barrel.

9. A syringe comprising a barrel assembly as described in claim 8, a gasket slidably housed within the barrel, and a plunger for moving the gasket.

10. The syringe according to claim 9, wherein the plunger has a tip portion housed within the barrel, and the plunger is provided with a stopper portion on the portion housed within the barrel, which contacts the grip and restricts the plunger from detaching from the barrel.

11. The syringe according to claim 9 or 10, wherein the plunger is not connected to the gasket and has a gasket pressing portion at its tip that contacts the base end of the gasket.

12. The syringe according to any one of claims 9 to 11, wherein a drug is stored in the barrel.

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