JP6478325B2 - Gasket for prefilled syringe and prefilled syringe - Google Patents

Description

  The present invention relates to a prefilled syringe, and more particularly to a gasket for a prefilled syringe.

As a syringe (syringe) used for medical use, there is a prefilled syringe prefilled with a chemical solution.
Prefilled syringes are not used for transferring medicines from vials to syringes, and are therefore being used more widely in medical settings because they are easy to use and can prevent drug solutions from being mixed.

  Moreover, what laminated | stacked the inert film is often used for the gasket used for a prefilled syringe. This is because the gasket in which the inert film is laminated can prevent direct contact between the chemical solution and the rubber portion of the gasket, and the chemical resistance is improved. However, the inert film is not as elastic as rubber, and the gasket having the inert film laminated on the entire surface has a problem in airtightness when inserted into a syringe.

  Therefore, a gasket with improved airtightness while improving chemical resistance has been proposed by laminating an inert film only on the wetted surface and making the sliding part a rubber surface without laminating an inert film. ing. (See Patent Document 1)

JP 2012-147859 A

Conventionally proposed gaskets in which an inert film is laminated only on the wetted part have the disadvantages that defective products are likely to occur in the molding and punching processes and the yield is poor, and improvements have been demanded.
The present invention has been made based on such a background, and a main object thereof is to provide a gasket for a prefilled syringe having improved chemical resistance and airtightness.

The invention according to claim 1 has a rubber main body in which the top surface of the cylindrical body is a liquid contact part, and the peripheral surface is a sliding part in contact with the inner surface of the syringe barrel, and the top surface of the main body is An annular protrusion is provided on the peripheral surface on the top surface side when viewed in the axial direction of the main body, and an annular protrusion as the sliding portion is formed on the peripheral surface of the top surface and the annular surface. projections and is connected at the periphery of the enlarged diameter to be inclined from the outer peripheral edge, characterized in that it comprises an inert film said laminated on the entire top surface except for the front distichum edge, for prefilled syringe It is a gasket.
According to the second aspect of the present invention, the outer diameter ( maximum outer diameter of the top surface region on which the inert film is laminated ) φ1 of the circular outer peripheral edge φ1 is 97.7% or more of the diameter φ2 of the annular protrusion, and 99 The gasket for prefilled syringes according to claim 1, wherein the gasket is 8% or less.

The invention according to claim 3 is the gasket for prefilled syringe according to claim 2, wherein the annular protrusion has a flat top portion of 0.3 to 0.8 mm in the axial direction of the main body. .
According to a fourth aspect of the present invention, the inert film is selected from any one or more of PTFE, ETFE, PFA, FEP, PCTFE, PVDF, PVF or their modified fluororesin film, nylon, and ultra high molecular weight PE. It is a gasket for prefilled syringes as described in any one of Claims 1-3.

The invention according to claim 5 is the gasket for prefilled syringe according to any one of claims 1 to 4, wherein the thickness of the inert film is 0.05 mm or more and 0.15 mm or less. It is.
According to the sixth aspect of the present invention, the center line surface roughness Ra of the top surface of the top surface of the cylindrical body on which the inert film is stacked is 1.0 μm or less, and the inert film is stacked. 6. The prefilled syringe gasket according to claim 1, wherein a center line surface roughness Ra of a non-sliding portion is 1.5 μm or more and 5.0 μm or less.

  Invention of Claim 7 is a prefilled syringe characterized by including the cylindrical syringe barrel and the gasket as described in any one of Claims 1-6 stoppered by the said syringe barrel. .

  According to the present invention, a gasket having excellent chemical resistance for a prefilled syringe and having improved hermeticity and a prefilled syring using the gasket can be obtained.

FIG. 1 is a view showing a prefilled syringe according to an embodiment of the present invention in an exploded state. FIG. 2A is a cross-sectional view of a gasket according to one embodiment of the present invention, and FIG. 2B is a plan view of the gasket according to one embodiment of the present invention. FIG. 3 is a schematic punching diagram showing an example of a gasket manufacturing method. FIG. 4 is an illustrative punching diagram showing an example of a gasket manufacturing method.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a prefilled syringe 10 according to an embodiment of the present invention in an exploded state. In FIG. 1, half of the syringe barrel 11 and the gasket 13 are shown in cross section.
Referring to FIG. 1, a prefilled syringe 10 includes a cylindrical syringe barrel 11, a plunger 12 that can be combined with the syringe barrel 11 and can reciprocate in the syringe barrel 11, and a gasket 13 that is attached to the tip of the plunger 12. Including. The gasket 13 includes a main body 14 made of an elastic material (such as rubber or elastomer), and an inert film 15 laminated on the front end surface (top surface) of the main body 14. The gasket 13 is provided with an annular protrusion 23 as a sliding portion that is in airtight and liquid tight contact with the inner peripheral surface 16 of the syringe barrel 11.

The plunger 12 is made of, for example, a resin plate piece having a cross-shaped cross section, and is provided with a head portion 18 to which a gasket 13 is attached at a tip portion thereof. The head portion 18 is made of a resin integrally formed with the plunger 12 and is processed into a male screw shape.
The gasket 13 has a substantially cylindrical shape with a short axis, and the tip surface (top surface) has, for example, an obtuse angled shape in which the central portion of the shaft protrudes. A fitting recess 21 having a female thread shape carved in the axial direction from the rear end surface is formed. When the head portion 18 of the plunger 12 is screwed into the fitting recess 21 of the gasket 13, the gasket 13 is attached to the tip of the plunger 12.

2A and 2B are views for explaining a gasket 13 according to one embodiment of the present invention. FIG. 2A is a longitudinal sectional view, and FIG. 2B is a plan view. In FIG. 2A, the orientation of the gasket 13 is shown upside down from FIG.
The gasket 13 has a cylindrical rubber main body 14. The top surface 22 of the main body 14 has an obtuse angle-shaped formation in which the axial center portion of the main body 14 protrudes, and the inert film 15 is laminated on the top surface 22.

On the peripheral surface of the cylindrical main body 14, an annular protrusion 23 is formed as a sliding portion in contact with the inner peripheral surface 16 of the syringe barrel 11 (see FIG. 1). The annular protrusion 23 is formed on the peripheral surface on the top surface 22 side when viewed in the axial direction of the main body 14.
In this embodiment, the first concave ring portion 24, the second annular protrusion 25, and the second concave ring are arranged on the peripheral surface of the main body 14 in the direction away from the top surface 22 when viewed in the axial direction of the main body 14. A portion 26 and a third annular protrusion 27 are formed. The annular protrusion 23, the second annular protrusion 25, and the third annular protrusion 27 function as a sliding portion.

As described above, the rear end face 28 of the main body 14 is formed with the female thread-shaped fitting recess 21 carved in the axial direction.
One of the features of the gasket 13 according to this embodiment is that the inert film 15 laminated on the top surface 22 is laminated on the entire top surface 22 except the peripheral edge 30 of the top surface 22 connected to the annular protrusion 23. That is. In other words, the maximum outer diameter φ1 of the top surface area where the inert film 15 is laminated is slightly smaller than the diameter φ of the annular protrusion 23.

Specifically, when comparing the maximum outer diameter φ1 of the top surface region where the inert film 15 is laminated with the diameter φ2 of the annular protrusion 23,
0.977φ2 ≦ φ1 ≦ 0.998φ2
It is set in the relationship.
In other words, (φ2−φ1) /φ2×100=0.2 to 2.3 (%).

Further, the gasket according to this embodiment is characterized in that the width in the vertical direction of the annular protrusion 23, that is, the width L1 of the flat top portion 23A of the annular protrusion 23 when viewed in the axial direction of the main body 14 is 0.3 to 0.8 mm. It is set to.
The gasket 13 according to this embodiment has the following operational effects.
First, since the inert film 15 is laminated on almost the entire top surface 22, the top surface 22 that is the liquid contact surface is covered with the inert film 15, and direct contact between the chemical solution and the rubber main body 14 is as much as possible. Prevention and chemical resistance. Further, since the inert film is not laminated on the sliding surfaces (the annular protrusion 23, the second annular protrusion 25, and the third annular protrusion 27), the airtightness between the gasket 13 and the inner peripheral surface 16 of the syringe barrel 11 is eliminated. The property is sufficiently achieved by the elasticity of the rubber body 14. Further, in this embodiment, the outer edge of the laminated region of the inert film 15 is made smaller than the outer diameter of the annular protrusion 23 continuous from the top surface 22, so that the annular protrusion 23 is formed even when the gasket is displaced. There is no uneven contact with the syringe barrel 11, and sufficient airtightness can be ensured. Further, since the airtightness can be sufficiently secured, it is not necessary to make the vertical width L1 of the top 23A of the annular projection 23 so long that the slidability of the gasket 13 can be sufficiently secured. In addition, what is necessary is just to adjust suitably the relationship between (phi) 1 and (phi) 2 with the capacity | capacitance of the syringe barrel 11 in which the gasket 13 is used.

  The material of the inert film 15 laminated on the liquid contact surface (top surface 22) is any one of PTFE, ETFE, PFA, FEP, PCTFE, PVDF, PVF, or a modified fluororesin film thereof, nylon, and ultra high molecular PE. Or one or more are selected. The film thickness is preferably 0.05 to 0.15 mm. More preferably, it is 0.05-0.08 mm. When the thickness of the film is 0.05 mm or less, the inert film 15 may be broken when the rubber main body 14 and the inert film 15 are integrally formed by a vacuum press. When the thickness is 0.15 mm or more, there is no risk of the inert film 15 being broken, but there is an unnecessary cost increase for the film thickness and an increase in cost due to accelerated consumption of the punching blade at the time of punching. Absent.

  Furthermore, the center line surface roughness Ra of the inert film 15 laminated on the liquid contact surface (top surface 22) is desirably 1.0 μm or less. More preferably, Ra = 0.5 μm or less. There is a problem that bubbles are likely to adhere to the inner peripheral surface 16 of the syringe and the liquid contact surface (top surface 22) of the gasket 13 when the chemical solution is filled. There is a tendency to be easy to do. For this reason, from the viewpoint of preventing the generation of bubbles, the liquid contact surface (top surface 22) on which the inert film 15 is laminated is desirably Ra = 1.0 μm or less.

  On the other hand, the center line surface roughness Ra of the sliding portions 23, 25, 27 is desirably 1.0 to 5.0 μm. When Ra = 1.0 μm or less, the gaskets 13 are easily adhered to each other, and once adhered, it is difficult to separate. If Ra = 5.0 μm or more, fine particles are likely to be deposited on the gasket surface, which is inappropriate from the sanitary aspect of the gasket 13.

<Gasket manufacturing method>
Next, the manufacturing method of the gasket 13 of embodiment is demonstrated.
3 and 4 are schematic cross-sectional views showing the manufacturing process (punching process) of the gasket 13.
First, the inert film 15 and the unvulcanized rubber sheet 104 are stacked and placed in a molding die, and heated and compressed by a vacuum press. By heat compression, vulcanization adhesion and molding of the inert film 15 and the unvulcanized rubber sheet 104 are performed. As a result, a molded sheet 105 in which a plurality of shapes of the gasket 13 and a plurality of eccentricity prevention rings 106 are formed is obtained. The gasket 13 is formed with a liquid contact portion and a sliding portion having an annular protrusion.

As the rubber sheet 104, synthetic rubber and thermoplastic elastomer can be used. Among these, synthetic rubber is preferable and butyl rubber is more preferable because good airtightness can be obtained. As the butyl rubber, halogenated butyl rubber such as chlorinated butyl rubber can be preferably used.
After molding, silicone is applied to the sliding portion side of the molded sheet 105. The silicone is preferably applied from the rubber sheet 104 side of the molding sheet 105 (the side where the sliding portion is molded). Thereby, since silicone does not adhere to a liquid-contact part, contamination of the chemical | medical solution by silicone can be prevented.

Next, as shown in FIG. 3, the sliding portion of the molded sheet 105 is set on the lower blade 101 of the punching die. Thereafter, in order to eliminate the eccentric removal defect, as shown in FIG. 4, the tension plate 102 is lowered from the liquid contact portion side of the molded sheet 105, tension is applied to the burr portion of the molded sheet 105, and the molded sheet 105 is moved to the lower blade. 101.
In this state, the upper blade 103 is lowered from the liquid contact portion side of the molded sheet 105, and the burr portion of the molded sheet 105 is cut to approximately the same diameter as the annular protrusion.

At the time of punching, the tension plate 102 presses the eccentricity prevention ring 106, whereby the molded sheet 105 is pulled outward. In this state, when the upper blade 103 and the lower blade 101 intersect, the cut surface of the cut product becomes oblique, and the contour portion of the top surface 22 is obliquely cut as shown in FIG.
In addition, it is preferable that the blade edge 103B at the lower end of the upper blade 103 is a blade edge that is inclined from the outside to the inside as shown in the drawing.

An evaluation test of the gasket 13 described in FIG. 2 was performed. The size of the gasket 13 is for 5 mL, and the syringe barrel 11 into which the gasket 13 is fitted has an inner diameter of 12.45 mm and is made of COP.
The gasket 13 was evaluated for airtightness and slidability. Each test was performed with N number = 10.
For the airtightness evaluation, a pressure test and a suction test were performed in accordance with JIS T3210 (sterilized syringe standard).

<Pressure test>
Distilled water is sucked up to the position of the nominal volume scale, 3/4 of the nominal volume scale, and 1/2 of the nominal volume scale in the syringe barrel that has been sufficiently wiped off water, and this is fixed horizontally and the tip of the syringe barrel nozzle After sealing, the plunger rod was fastened to the gasket 13. A pressure of 343 kPa was applied to the plunger rod for 10 seconds, and the presence or absence of water droplets falling from the gap between the gasket 13 and the syringe barrel was confirmed. In the result table, the number of syringe barrels in which water droplets fell was described.

<Suction test>
After sucking water up to 1/4 of the nominal volume scale of the syringe barrel and sealing the nozzle tip of the syringe barrel, when the plunger rod is pulled to the nominal volume scale, the gap between the gasket 13 and the syringe barrel The presence or absence of continuous bubble generation was confirmed. In the result table, the number of syringe barrels in which continuous bubbles were generated was described. The case where the number of continuous bubbles generated was 0 was evaluated as ◯, the case of 1 as Δ, and the case of 2 or more as X.

<Slidability test>
The plunger rod was fitted into the gasket 13 inserted into the syringe barrel, the plunger rod was pushed in using an autograph (manufactured by Shimadzu Corporation, AUTOGRAPH AG-1000D type), and the load at that time was measured. The speed at which the gasket 13 was slid was 100 mm / min. The sliding distance is 45 mm. The test was performed with the syringe barrel empty. In the table of results, the average value of the sliding values is shown. When the load is 9 N or less, it can be said that the plunger rod can be moved without difficulty during use, which is favorable. The case where the load was 9N or less was rated as ◯, the case where the load was 9.1 to 11.0N was Δ, and the case where the load was 11.1N or more was rated as x.

  As a comprehensive evaluation, ◎ when the number of ○ in each test is three, ◎ when there are two ○ in each test, △ when there is one ○ in each test, and 0 in each test Was marked with x. (There was no x in the overall evaluation.)

  From the above measurement results, it can be seen that a preferable gasket for a prefilled syringe can be obtained if the maximum outer diameter φ1 of the top surface region where the inert film is laminated is made slightly smaller than the diameter φ2 of the annular protrusion 23.

DESCRIPTION OF SYMBOLS 10 Prefilled syringe 11 Syringe barrel 12 Plunger 13 Gasket 14 Main body 15 Inactive film 16 Inner peripheral surface 18 Head part 21 Fitting recessed part 22 Top surface 23 Annular protrusion 24 The 1st recessed ring part 25 The 2nd annular protrusion 26 The 2nd recessed ring Part 27 Third annular protrusion 28 Rear end face 30 Peripheral part

Claims (7)

The top surface of the cylindrical body has a wetted part, a rubber body whose peripheral surface is a sliding part in contact with the syringe barrel inner surface ,
The top surface of the main body has a circular outer periphery,
As seen in the axial direction of the main body, an annular projection as the sliding portion is formed on the peripheral surface on the top surface side,
The outer peripheral edge of the top surface and the annular protrusion are connected by a peripheral edge portion that is inclined and expands from the outer peripheral edge,
Characterized in that it comprises an inert film said laminated on the entire top surface except for the front distichum edge gasket prefilled syringe. The outer diameter of the circular outer peripheral edge ( the maximum outer diameter of the top surface region on which the inert film is laminated ) φ1 is 97.7% or more and 99.8% or less of the diameter φ2 of the annular protrusion. The gasket for prefilled syringes according to claim 1, characterized in that it is characterized by the following.   The gasket for a prefilled syringe according to claim 2, wherein the annular protrusion has a flat top portion of 0.3 to 0.8 mm in the axial direction of the main body.   The inert film is selected from any one or more of PTFE, ETFE, PFA, FEP, PCTFE, PVDF, PVF or their modified fluororesin film, nylon, and ultra high molecular weight PE. The gasket for prefilled syringes as described in any one of these.   The prefilled syringe gasket according to any one of claims 1 to 4, wherein the inert film has a thickness of 0.05 mm or more and 0.15 mm or less.   The centerline surface roughness Ra of the top surface on which the inert film is laminated on the top surface of the cylindrical main body is 1.0 μm or less, and the centerline surface of the sliding portion on which the inert film is not laminated Roughness Ra is 1.5 micrometers or more and 5.0 micrometers or less, The gasket for prefilled syringes as described in any one of Claims 1-5 characterized by the above-mentioned.   A prefilled syringe comprising a cylindrical syringe barrel and the gasket according to any one of claims 1 to 6, which is plugged into the syringe barrel.

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