Patent Description:
<CIT> relates to a tip cap including an inner cap from an elastomeric material for seling engagement with a tip of a syringe barrel.

In a conventional pre-filled syringe filled with a liquid beforehand, a cap to close a nozzle portion liquid tight is mounted to a distal end of a barrel in order to prevent leakage of a liquid inside the syringe from a syringe distal end opening prior to use of the syringe, particularly during transportation (refer to, for example, <CIT>).

The cap disclosed in <CIT> includes an inner cap formed of an elastic material and a hard outer cap fixed around the inner cap, with an outer screw provided on the outer cap being configured to be engaged with an inner screw provided at a Luer collar fixed at a distal end portion of a syringe barrel, so as to cause the inner cap to seal the distal end portion of the syringe barrel liquid tight.

In the case of the cap disclosed in <CIT>, even slight movement of the cap in a distal direction with respect to the syringe barrel would disable the sealing function of the cap, leading to leakage of the liquid to the outside of the cap.

The present invention has been made in consideration of such problems, and aims to provide a syringe barrel, a syringe barrel manufacturing method, and a pre-filled syringe, capable of preventing leakage of a liquid to the outside of a cap even in a case where the cap slightly moves in the distal direction with respect to a barrel body.

To achieve the above object, a syringe barrel of the present invention relates to a syringe barrel according to claim <NUM>.

According to the syringe barrel of the present invention having the above configuration, the cylindrical wall of the inner cap formed of an elastic material is compressed between the outer peripheral surface of the nozzle portion and the inner peripheral surface of the outer cap even in a case where the cap slightly moves in the distal direction from the state of close contact with the distal end surface of the nozzle portion. This configuration allows close contact between the outer peripheral surface of the nozzle portion and the inner peripheral surface of the cylindrical wall, forming a liquid tight seal at a close contact portion. Accordingly, it is possible to effectively prevent leakage of the liquid in the barrel body to the outside of the cap.

In the syringe barrel described above, an axial length of a compressed portion, which a portion of the cylindrical wall compressed between the nozzle portion and the outer cap in a state in which the base portion is in close contact with the distal end surface of the nozzle portion, is <NUM> or more.

This configuration appropriately increases a length of a liquid tight seal due to the close contact between the cylindrical wall and the nozzle portion, making it possible to suitably prevent leakage of a drug solution to the outside of the cap. Furthermore, for example, it is possible to reliably prevent liquid leakage in a pre-filled syringe determined to be a non-defective product in a case where a loosening length threshold for determining acceptance in the cap mounting inspection is <NUM>.

In the syringe barrel described above, the compressed portion may include an enlarged diameter portion protruding outward in a radial direction more than the other portions of the cylindrical wall.

This configuration can easily increase a close contact area (liquid tight seal area) between the cylindrical wall and the nozzle portion.

In the syringe barrel described above, the inner peripheral surface of the cylindrical wall may have a shape substantially corresponding to the outer peripheral surface of the nozzle portion.

With this configuration, the axial length of the close contact portion between the cylindrical wall and the nozzle portion is longer than the axial length of the enlarged diameter portion, making it easier to increase the close contact area between the cylindrical wall and the nozzle portion (liquid tight seal area).

In the syringe barrel described above, the axial length of the compressed portion is shorter than the axial length of the cylindrical wall.

With this configuration, it is possible to effectively restrain an increase in a cap opening torque (torque needed to turn the cap for opening the cap) due to the presence of the compressed portion.

In the syringe barrel described above, the compressed portion is disposed at a distal end portion of the cylindrical wall.

This configuration forms a liquid tight seal at the distal end portion of the outer peripheral surface of the nozzle portion, making it possible to further effectively prevent liquid leakage to the outside of the cap.

In the syringe barrel described above, a compressibility of the compressed portion, which a portion of the cylindrical wall compressed between the nozzle portion and the outer cap in the mounted state, may be in a range of <NUM>% to <NUM>%.

With this configuration, it is possible to effectively prevent an excessive increase in the opening torque of the cap while holding satisfactory pressure resistance.

In the syringe barrel described above, a diameter of the distal end opening of the nozzle portion may be <NUM> or more.

With a relatively large diameter of the distal end opening of the nozzle portion, a large pressure would be applied to the inner cap even in a state where the cap is tightly closed (state where the inner cap and the distal end surface of the nozzle portion are in close contact with each other), leading to a high probability of liquid leakage in the absence of the compressed portion. The present invention is particularly useful in that liquid leakage can be effectively prevented by the presence of the compressed portion even in a case where the diameter of the distal end opening of the nozzle portion is as relatively large as <NUM> or more.

It is allowable to have a configuration in which the barrel body includes: a lock adapter disposed on an outer side of the nozzle portion; and an annular recess disposed between the nozzle portion and the lock adapter and recessed in a proximal direction, the outer cap includes a proximal end cylindrical portion covering the cylindrical wall, the proximal end cylindrical portion of the outer cap includes an engaging portion on an inner peripheral surface of the proximal end cylindrical portion, the engaging portion being configured to engage with the cylindrical wall, wherein, in the mounted state, the cylindrical wall of the inner cap and the proximal end cylindrical portion of the outer cap are inserted into the annular recess, and the inner peripheral surface of the cylindrical wall is in close contact with the outer peripheral surface of the nozzle portion, and when the cap in the mounted state is removed from the barrel body, engagement between the engaging portion and the cylindrical wall allows a moving force of the outer cap to move with respect to the lock adapter to be transmitted directly to the cylindrical wall.

According to this configuration, it is possible to move the inner cap together with the movement of the outer cap at removal of the cap from the barrel body even in a case where the inner peripheral surface of the cylindrical wall of the inner cap is pseudo fixed (adhered) to the outer peripheral surface of the nozzle portion, making it possible to restrain expansion of the cylindrical wall. This makes is possible to prevent the drug solution from spouting out at the time of opening the cap.

It is allowable to have a configuration in which the engaging portion is an engaging protrusion that protrudes inward in a radial direction from the inner peripheral surface of the proximal end cylindrical portion of the outer cap, and the cylindrical wall includes a engaged portion that is configured to be engaged with the engaging protrusion, and when the cap in the mounted state is removed from the barrel body, engagement of the engaging protrusion with the engaged portion from a proximal end thereof allows the moving force to be transmitted directly to the cylindrical wall.

This configuration enables acquisition of a further satisfactory engaging force, making it possible to further reliably move the inner cap together with the movement of the outer cap when the cap is removed from the barrel body.

The engaged portion may be a proximal end surface of the cylindrical wall.

With this configuration, the proximal end surface of the cylindrical wall is pressed in the distal direction by the engaging portion when the cap is removed from the barrel body, making it possible to move the entire cylindrical wall integrally with the outer cap. In addition, the proximal end surface of the cylindrical wall can be utilized as it is as the engaged portion, making it possible to avoid structural complication of the cylindrical wall due to the presence of the engaged portion.

The engaged portion may be an engaged protrusion that protrudes outward in the radial direction from the outer peripheral surface of the cylindrical wall.

It is allowable to have a configuration in which the lock adapter includes a female screw portion on an inner peripheral surface of the lock adapter, the outer cap includes a male screw portion that is disposed on the outer peripheral surface of the proximal end cylindrical portion, the male screw portion being configured to be screwed together with the female screw portion, the female screw portion and the male screw portion are screwed with each other in the mounted state, the engaging portion is a plurality of engaging ribs extending along an axis of the proximal end cylindrical portion, the cylindrical wall includes a engaged portion that is disposed on the outer peripheral surface of the cylindrical wall, the engaged portion being configured to be engaged with the plurality of engaging ribs, and when the outer cap is rotated with respect to the lock adapter to remove the cap in the mounted state from the barrel body, engagement between the plurality of engaging ribs and the engaged portion allows the moving force of the outer cap to rotationally move with respect to the lock adapter to be transmitted directly to the cylindrical wall.

This configuration causes the cylindrical wall of the inner cap to rotate simultaneously with the outer cap when the cap is removed from the barrel body, making it possible to further reliably move the inner cap together with the movement of the outer cap.

The barrel body may be formed of a cyclic olefin polymer or a cyclic olefin copolymer.

With the barrel body formed of a cyclic olefin polymer or a cyclic olefin copolymer, the inner cap is likely to be pseudo fixed to the nozzle portion. Accordingly, the present invention is capable of restraining expansion of the cylindrical wall at the time of opening the cap is particularly useful.

The inner cap may be formed from butyl rubber.

With the barrel body formed from butyl rubber, the inner cap is further likely to be pseudo fixed to the nozzle portion. Accordingly, the present invention is capable of restraining expansion of the cylindrical wall at the time of opening the cap is particularly useful.

Sterilization treatment involving a thermal load onto the syringe barrel may be applied on the syringe barrel in the mounted state.

With application of sterilization treatment involving a thermal load, the inner cap is further likely to be pseudo fixed to the nozzle portion. Accordingly, the present invention is capable of restraining expansion of the cylindrical wall at the time of opening the cap is particularly useful.

Furthermore, the pre-filled syringe of the present invention includes: any one of the syringe barrels described above; a gasket slidably inserted in the barrel body; a plunger coupled or couplable to the gasket, and a drug solution filled in a liquid chamber formed by the barrel body and the gasket.

A syringe barrel manufacturing method according to the present invention including: an assembling step of mounting the cap to the barrel body to assemble a barrel assembly; a photographing step of photographing a reference portion of the barrel body and a reference portion of the cap as one image using a camera; and a determination step of determining that the barrel assembly is a non-defective product if a distance between the reference portion of the barrel body and the reference portion of the cap is a predetermined value or less in the image photographed by the camera, in which an axial length of a compressed portion, which is a portion of the cylindrical wall compressed between the nozzle portion and the outer cap in a state in which the base portion is in close contact with the distal end surface of the nozzle portion, is the predetermined value or more.

With the syringe barrel and the syringe barrel manufacturing method, and the pre-filled syringe of the present invention, it is possible to prevent the leakage of a liquid to the outside of the cap even in a case where the cap slightly moves in the distal direction with respect to the barrel body.

Preferred embodiments of a syringe barrel, a syringe barrel manufacturing method, and a pre-filled syringe according to the present invention will be described below with reference to the accompanying drawings.

A pre-filled syringe <NUM> according to a first embodiment illustrated in <FIG> includes, as main components: a barrel body <NUM> formed of a hollow body provided with a nozzle portion <NUM>; a cap <NUM> for sealing the nozzle portion <NUM> of the barrel body <NUM>; a gasket <NUM> slidably inserted in the barrel body <NUM>; and a drug solution M filled in a liquid chamber <NUM> formed by the barrel body <NUM> and the gasket <NUM>. The barrel body <NUM> and the cap <NUM> constitute a syringe barrel <NUM>.

The barrel body <NUM> includes: a body portion <NUM> having a substantially cylindrical shape and including a proximal end opening <NUM> formed at a proximal end; a nozzle portion <NUM> (refer to <FIG>) provided at a distal end of the barrel portion <NUM>; a lock adapter <NUM> provided on an outer side of the nozzle portion <NUM>; and a flange <NUM> protruding outward in a radial direction from the distal end of the body portion <NUM>. In the barrel body <NUM> in the illustrated example, the body portion <NUM>, the nozzle portion <NUM>, the lock adapter <NUM>, and the flange <NUM> are integrally formed.

The gasket <NUM> is inserted through the barrel body <NUM> via the proximal end opening <NUM>. The proximal side of the barrel body <NUM> is sealed liquid tight with the gasket <NUM>, and the drug solution M is sealed within the barrel body <NUM>.

The gasket <NUM> is formed of an elastic material such as a rubber material. The gasket <NUM> allows its outer peripheral portion to be in liquid tight contact with the inner peripheral surface of the barrel body <NUM>, and is slidably disposed in the barrel body <NUM>. The gasket <NUM> is coupled with a distal end portion of the plunger <NUM>. Operation of pressing the plunger <NUM> in the distal direction performed by the user causes the gasket <NUM> to slide in the distal direction inside the barrel body <NUM>. Note that the plunger <NUM> may be coupled to the gasket <NUM> at the time of administration of the drug solution M to a patient.

As illustrated in <FIG>, the nozzle portion <NUM> is diametrically reduced from the center on the distal end of the barrel body <NUM> with respect to the barrel body <NUM> and extends in the distal direction. The nozzle portion <NUM> includes a tapered outer peripheral surface 20a having outer diameter reducing toward the distal direction. That is, the outer peripheral surface 20a of the nozzle portion <NUM> constitutes a Luer taper. As illustrated in <FIG>, the nozzle portion <NUM> includes a liquid path <NUM> communicating with the liquid chamber <NUM> in the barrel body <NUM> and penetrating in the axial direction. The distal end of the liquid path <NUM> forms a distal end opening <NUM> of the nozzle portion <NUM>.

In a state where the cap <NUM> is removed from the nozzle portion <NUM>, a needle unit (not illustrated) detachably provided on the nozzle portion <NUM>. The needle unit includes: a needle body having a needle point; and a needle hub having a protrusion fixed to the proximal end portion of the needle body and protruding outward. The nozzle portion <NUM> can be taper-fitted to an inner peripheral portion of the needle hub. In use of the pre-filled syringe <NUM>, the cap <NUM> is unplugged (removed from the barrel <NUM> and the lock adapter <NUM>), and instead the needle hub of the needle unit is connected to the nozzle portion <NUM> and the lock adapter <NUM>.

The lock adapter <NUM> in the illustrated example is formed in a substantially hollow circular shape extending in the distal direction from the distal end of the body portion <NUM> and surrounding the nozzle portion <NUM>. The above-described nozzle portion <NUM> protrudes more toward the distal direction than the lock adapter <NUM>, forming an annular recess <NUM> recessed in the proximal direction between the lock adapter <NUM> and the nozzle portion <NUM>. The inner peripheral surface of the lock adapter <NUM> includes a female screw portion <NUM>. The female screw portion <NUM> is removably engaged with a male screw portion <NUM> (described below) of the cap <NUM>. In a state where the cap <NUM> is removed from the barrel body <NUM>, the female screw portion <NUM> is engageable with a protrusion provided on the needle hub of the above-described needle unit.

While the lock adapter <NUM> of the illustrated example is integrally formed at the distal end portion of the body portion <NUM> as a portion of the barrel body <NUM>, the lock adapter <NUM> may be integrally formed at the proximal end portion of the nozzle portion <NUM>. Alternatively, the lock adapter <NUM> may be configured as a separate component from the body portion <NUM> and the nozzle portion <NUM>, and may be a member fixed to the barrel body <NUM> or the nozzle portion <NUM>.

Examples of the constituent material of the barrel body <NUM> include various resins such as polypropylene, polyethylene, polystyrene, polyamide, polycarbonate, polyvinyl chloride, poly- (<NUM>-methylpentene-<NUM>), acrylic resin, acrylonitrile-butadiene-styrene copolymer, polyester such as polyethylene terephthalate, and cyclic olefin polymer.

The cap <NUM> is removably mounted to the nozzle portion <NUM>, and seals the distal end opening <NUM> of the nozzle portion <NUM>. The illustrated cap <NUM> is detachably provided on the nozzle portion <NUM>. As illustrated in <FIG>, the cap <NUM> includes: an inner cap <NUM> for sealing the distal end opening <NUM>; and a hollow cylindrical outer cap <NUM> for supporting the inner cap <NUM>.

The inner cap <NUM> is formed of an elastic material. In a state before use (hereinafter also referred to as "mounted state") where the cap <NUM> is mounted to the nozzle portion <NUM>, the inner cap <NUM> is in liquid tight close contact with the nozzle portion <NUM> so as to restrain leakage of the drug solution M to the outside of the cap <NUM>. In <FIG>, the inner cap <NUM> is in close contact over a full circumference with each of the outer peripheral surface 20a and the distal end surface 20b of the nozzle portion <NUM>.

Examples of the elastic material of the inner cap <NUM> include various rubber materials such as natural rubber, butyl rubber, isoprene rubber, butadiene rubber, styrenebutadiene rubber, and silicone rubber, or various types of thermoplastic elastomer such as polyurethane type, polyester type, polyamide type, olefin type, and styrene type, or a mixture of these.

As illustrated in <FIG> and <FIG>, the outer cap <NUM> is fixed to the outer periphery of the inner cap <NUM>. The male screw portion <NUM> to be releasably screwed to the female screw portion <NUM> of the lock adapter <NUM> is formed on the proximal end outer peripheral portion of the outer cap <NUM>. On more toward the distal side than the male screw portion <NUM> on the outer peripheral portion of the outer cap <NUM>, there is provided a stopper <NUM> protruding outward in the radial direction.

In a state where the cap <NUM> is firmly (completely) mounted to the nozzle portion <NUM> and the lock adapter <NUM>, the outer cap <NUM> is screwed to the lock adapter <NUM> up to a position where the proximal end surface of the stopper <NUM> and the distal end surface of the lock adapter <NUM> are in contact with each other. Accordingly, in the process of assembling the syringe barrel <NUM>, checking the presence or absence and the size of a gap between the stopper <NUM> and the lock adapter <NUM> leads to checking whether the cap <NUM> is satisfactorily mounted to the barrel body <NUM>. While the stopper <NUM> in the illustrated example is formed in an annular shape over a full circumference in the circumferential direction of the outer cap <NUM>, it is allowable to provide a plurality of the stoppers <NUM> at intervals in the circumferential direction.

Next, a configuration of the inner cap <NUM> will be described in more detail. The inner cap <NUM> includes a base portion <NUM> located on more toward the distal side than the nozzle portion <NUM> in the mounted state; and a cylindrical wall <NUM> extending from the base portion <NUM> in the proximal direction. The base portion <NUM> and the cylindrical wall <NUM> forms a recess <NUM> recessed in the distal direction. The base portion <NUM> constitutes a distal side portion of the inner cap <NUM>.

The outer peripheral portion of the base portion <NUM> includes an annular groove <NUM> recessed inward in the radial direction, and an annular protrusion <NUM> provided on the inner peripheral portion of the outer cap <NUM> is engaged with the annular groove <NUM>. This configuration inhibits a relative movement in the axial direction between the inner cap <NUM> and the outer cap <NUM>. In <FIG>, the proximal end surface <NUM> (the bottom portion of the recess <NUM>) of the base portion <NUM> is brought into close contact over a full circumference with the distal end surface 20b of the nozzle portion <NUM> and slightly squeezed in the distal direction by the distal end surface 20b.

The cylindrical wall <NUM> is formed in a hollow cylindrical shape. In the mounted state of the cap <NUM>, the cylindrical wall <NUM> surrounds the nozzle portion <NUM>. Moreover, the cylindrical wall <NUM> is sandwiched in a compressed state between the outer peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface <NUM> of the outer cap <NUM> in a state where the base portion <NUM> is in close contact with the distal end surface 20b of the nozzle portion <NUM> (<FIG>) and in a state where the base portion <NUM> is apart from the distal end surface 20b of the nozzle portion <NUM> by a predetermined distance (<FIG>).

This brings the inner peripheral surface <NUM> of the cylindrical wall <NUM> into close contact over a full circumference with the outer peripheral surface 20a of the nozzle portion <NUM>, so as to form a liquid tight seal at this close contact portion in the state illustrated in <FIG> and <FIG>. This restrains leakage of the drug solution M to the outside of the cap <NUM> even in a case where the cap <NUM> slightly moves in the distal direction from the state of <FIG> and where the proximal end surface <NUM> of the base portion <NUM> is apart from the distal end surface 20b of the nozzle portion <NUM> as illustrated in <FIG>.

Specifically, the cylindrical wall <NUM> includes a compressed portion <NUM> compressed in the radial direction (wall thickness direction of the cylindrical wall <NUM>) between the outer peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface <NUM> of the outer cap <NUM>. Accordingly, the inner peripheral surface of the compressed portion <NUM> and the outer peripheral surface 20a of the nozzle portion <NUM> are in close contact over a full circumference with each other. In the present embodiment, the compressed portion <NUM> includes an enlarged diameter portion <NUM> (refer to also <FIG>) protruding outward in the radial direction rather than the other portion of the cylindrical wall <NUM>, and is sandwiched between the nozzle portion <NUM> and the inner peripheral surface <NUM> of the outer cap <NUM>, so as to form a high-intensity close contact portion a having higher degree of contact than other portions.

An outer peripheral surface 54a of the enlarged diameter portion <NUM> has a constant outer diameter along the axial direction and is in close contact with the inner peripheral surface of the outer cap <NUM> over the entire axial length. The outer peripheral portion of the cylindrical wall <NUM> includes: a distal side tapered portion <NUM> continuing to the distal end of the enlarged diameter portion <NUM> and decreasing an outer diameter toward the distal direction; and a proximal side tapered portion <NUM> continuing to the proximal end of the enlarged diameter portion <NUM> and decreasing an outer diameter in the proximal direction. Note that the compressed portion <NUM> is only required to be sandwiched between the nozzle portion <NUM> and the inner peripheral surface <NUM> of the outer cap <NUM> so as to be able to form a high-intensity close contact portion having a higher degree of contact than other portions. Therefore, the compressed portion <NUM> may include, instead of the enlarged diameter portion <NUM>, a reduced diameter portion protruding inward in a radial direction more than the other portions of the cylindrical wall <NUM> and provided on the inner peripheral portion of the cylindrical wall <NUM>.

An axial length L (length from the distal end to the proximal end of the outer peripheral surface 54a in close contact with the inner peripheral surface <NUM> of the outer cap <NUM>) of the compressed portion <NUM> (enlarged diameter portion <NUM> or the reduced diameter portion) is <NUM> or more, for example, and preferably <NUM> or more. With the axial length L of the compressed portion <NUM> set within the above range, it is possible to appropriately increase the length of the liquid tight seal (close contact region between the compressed portion <NUM> and the outer peripheral surface 20a), making it possible to suitably prevent leakage of the drug solution M to the outside of the cap <NUM>. In the present embodiment, the axial length L is <NUM> or more.

In an assembling step of the syringe barrel <NUM>, a cap mounting inspection may be performed to determine whether the cap <NUM> is satisfactorily mounted to the barrel body <NUM>. This inspection defines a state (<FIG>) in which the cap <NUM> is firmly mounted as a reference and makes determination of a non-defective product in a case where the cap <NUM> is loose at a predetermined length (for example, <NUM>) or less in the distal direction with respect to the reference, or makes determination of a non-non-defective product in a case where the cap is loose beyond the predetermined length. With the axial length L of the compressed portion <NUM> set to be longer than the loosening length determined to be non-conforming, it is possible to reliably prevent liquid leakage in the pre-filled syringe <NUM> using the syringe barrel <NUM> determined to be conforming.

Specifically, the manufacturing method of the syringe barrel <NUM> including such a cap mounting inspection includes an assembling step, a photographing step, and a determination step as follows.

In the assembling step, the cap <NUM> is mounted to the barrel body <NUM> to assemble the barrel assembly (syringe barrel <NUM>).

After completion of the assembling step, next, the photographing step is performed. In the photographing step, a reference portion of the barrel body <NUM> and a reference portion of the cap <NUM> are photographed by a camera <NUM> as one image (still image) as illustrated in <FIG>. In <FIG>, the reference portion of the barrel body <NUM> is the distal end of the lock adapter <NUM>, while the reference portion of the cap <NUM> is the proximal end of the stopper <NUM> of the outer cap <NUM>. A portion other than the distal end of the lock adapter <NUM> in the barrel body <NUM> may be set as a reference portion and a portion other than the proximal end of the stopper <NUM> in the outer cap <NUM> may be set as the reference portion.

After completion of the photographing step, a determination step is performed. The determination step determines the barrel assembly as a non-defective product in a case where a distance W between the reference portion of the barrel body <NUM> and the reference portion of the cap <NUM> is a predetermined value or less (for example, <NUM> or less) in the image photographed by the camera <NUM>. This determination is automatically made by a determination apparatus (computer) having an image processing function. The determination apparatus specifies the reference portion of the barrel body <NUM> and the reference portion of the cap <NUM> from the obtained image, for example using pattern matching, for example, and measures the distance between the reference portions. Then, the determination apparatus determines whether the barrel assembly is conforming or non-conforming on the basis of the obtained distance. The axial length L (refer to <FIG>) of the compressed portion <NUM> described above is the predetermined value or more.

In the present embodiment, the axial length L of the compressed portion <NUM> is shorter than the axial length of the cylindrical wall <NUM>. This makes it possible to restrain difficulty in opening the cap <NUM> due to an increase in opening torque of the cap <NUM> (torque required for turning the cap <NUM> to open). From such a viewpoint, the axial length L of the compressed portion <NUM> is set to, for example, <NUM> or less, preferably <NUM> or less, and more preferably <NUM> or less. The axial length L of the compressed portion <NUM> may be the same as the axial length of the cylindrical wall <NUM> unless emphasis is placed on the opening torque of the cap <NUM>.

Furthermore, in the present embodiment, the compressed portion <NUM> is provided at the distal end portion of the cylindrical wall <NUM>. This configuration forms a liquid tight seal at the distal end portion of the outer peripheral surface 20a of the nozzle portion <NUM>, making it possible to further effectively prevent leakage of the drug solution M to the outside of the cap <NUM>. The compressed portion <NUM> may be provided in the proximal side region of the cylindrical wall <NUM>.

In the mounted state of the cap <NUM>, the compressibility of the compressed portion <NUM> is in a range of, for example, <NUM>% to <NUM>%, preferably <NUM>% to <NUM>%. Here, the compressibility of the compressed portion <NUM> represents a ratio of the amount of strain to the thickness of the compressed portion <NUM> in the natural state (state where the compressed portion <NUM> is not sandwiched between the nozzle portion <NUM> and the outer cap <NUM>). When the amount of strain is δ, the thickness of the compressed portion <NUM> in the natural state is T0, and the thickness of the compressed portion <NUM> in the compressed state is T1, δ = T0 - T1 holds.

With the compressibility of less than <NUM>%, the degree of contact between the cylindrical wall <NUM> and the nozzle portion <NUM> might become weak, leading to a failure in obtaining desired pressure resistance performance. On the other hand, the compressibility exceeding <NUM>% might excessively increase the opening torque of the cap <NUM>, making it difficult to open the cap <NUM>. With setting of the compressibility in a range of <NUM>% to <NUM>%, it is possible to effectively prevent the cap opening torque of the cap <NUM> from becoming excessively large while maintaining satisfactory pressure resistance performance.

As described above, according to the syringe barrel <NUM> (pre-filled syringe <NUM>), it is possible to effectively prevent leakage of the drug solution M even in a case where the cap <NUM> slightly has moved in the distal direction from the state where the cap <NUM> is in close contact with the distal end surface 20b of the nozzle portion <NUM> and where the proximal end surface <NUM> of the base portion <NUM> of the inner cap <NUM> is slightly apart from the distal end surface 20b of the nozzle portion <NUM>. That is, even in a case where the proximal end surface <NUM> of the base portion <NUM> of the inner cap <NUM> is slightly apart from the distal end surface 20b of the nozzle portion <NUM> as illustrated in <FIG>, the cylindrical wall <NUM> of the inner cap <NUM> formed of an elastic material is compressed between the outer peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface <NUM> of the outer cap <NUM>. This configuration allows close contact between the outer peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface <NUM> of the cylindrical wall <NUM>, forming a liquid tight seal at a close contact portion. This restrains leakage of the drug solution M in the barrel body <NUM> to the outside of the cap <NUM>.

In the present embodiment, since the axial length L of the compressed portion <NUM> is <NUM> or more, it is possible to appropriately increase the length of the liquid tight seal formed by the close contact between the cylindrical wall <NUM> and the nozzle portion <NUM>. This configuration makes it possible to suitably prevent the leakage of the drug solution M to the outside of the cap <NUM>. Furthermore, for it is possible to reliably prevent liquid leakage in a pre-filled syringe <NUM> determined to be a non-defective product in a case where a loosening length threshold for determining acceptance in the cap mounting inspection is <NUM>.

In the present embodiment, the compressed portion <NUM> includes the enlarged diameter portion <NUM> protruding outward in the radial direction more than the other portion of the cylindrical wall <NUM>, making it easier to increase the close contact area between the cylindrical wall <NUM> and the nozzle portion <NUM> (liquid tight seal area). In addition, the inner peripheral surface <NUM> of the cylindrical wall <NUM> has a shape substantially corresponding to the outer peripheral surface 20a of the nozzle portion <NUM>. With this configuration, the axial length of the close contact portion between the cylindrical wall <NUM> and the nozzle portion <NUM> is longer than the axial length of the enlarged diameter portion <NUM>, making it further easier to increase the close contact area between the cylindrical wall <NUM> and the nozzle portion <NUM> (liquid tight seal area). The shape substantially corresponding to the outer peripheral surface 20a of the nozzle portion <NUM> represents a shape that allows most of the inner peripheral surface <NUM> of the cylindrical wall <NUM> to be in contact with the outer peripheral surface 20a of the nozzle portion <NUM>.

In the present embodiment, the axial length L of the compressed portion <NUM> is shorter than the axial length of the cylindrical wall <NUM>, making it possible to effectively restrain an increase in the opening torque of the cap <NUM> due to the presence of the compressed portion <NUM>.

In the present embodiment, the compressed portion <NUM> is provided at the distal end portion of the cylindrical wall <NUM>, leading to formation of liquid tight seal at the distal end portion of the outer peripheral surface 20a of the nozzle portion <NUM>. This makes is possible to further effectively prevent the liquid leakage to the outside of the cap <NUM>.

With the compressibility of the compressed portion <NUM> in a range of <NUM>% to <NUM>% in the present embodiment, it is possible to effectively prevent the cap opening torque of the cap <NUM> from becoming excessively large while maintaining satisfactory pressure resistance performance.

The present invention is particularly useful in that liquid leakage can be effectively prevented even when the diameter of the distal end opening <NUM> of the nozzle portion <NUM> is as relatively large as <NUM> or more. That is, with relatively large diameter of the distal end opening <NUM> of the nozzle portion <NUM>, a large pressure is applied to the inner cap <NUM> even in a state where the cap <NUM> is tightly closed (state where the inner cap <NUM> and the distal end surface 20b of the nozzle portion <NUM> are in close contact with each other). Therefore, when the diameter of a distal end opening of a nozzle portion is relatively large (for example, when the diameter is <NUM> or more) with a conventional cap without the compressed portion <NUM>, the liquid leakage is likely to occur. In contrast, according to the present invention, liquid leakage can be effectively prevented by the presence of the compressed portion <NUM> even when the diameter of the distal end opening <NUM> of the nozzle portion <NUM> is as relatively large as <NUM> or more.

While the above embodiment is an example in which the enlarged diameter portion <NUM> is provided on the outer peripheral surface of the cylindrical wall <NUM>, or the reduced diameter portion is provided on the inner peripheral surface of the cylindrical wall <NUM>, whereby the compressed portion <NUM> compressed in the radial direction is formed between the outer peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface <NUM> of the outer cap <NUM>. Alternatively, as illustrated in <FIG>, the compressed portion 52a may be formed by pressing the cylindrical wall <NUM> by an annular protrusion <NUM> provided on the inner peripheral surface <NUM> of the outer cap <NUM>.

Specifically, in <FIG>, the inner peripheral surface <NUM> of the outer cap <NUM> includes the annular protrusion <NUM> that protrudes inward in the radial direction and presses the cylindrical wall <NUM>. The annular protrusion <NUM> presses the distal end portion of the cylindrical wall <NUM> inward in the radial direction. The compressed portion 52a is a portion of the cylindrical wall <NUM>, sandwiched in a compressed state between the inner peripheral surface of the annular protrusion <NUM> and the outer peripheral surface 20a of the nozzle portion <NUM>.

In a state illustrated in <FIG> (state where the proximal end surface <NUM> of the base portion <NUM> is in close contact with the distal end surface 20b of the nozzle portion <NUM>) and a state where the base portion <NUM> is apart from the distal end surface 20b of the nozzle portion <NUM> by a predetermined distance (state similar to <FIG>), the inner peripheral surface of the compressed portion 52a is in close contact over a full circumference with the outer peripheral surface 20a of the nozzle portion <NUM>, and a liquid tight seal is formed at this close contact portion. This restrains leakage of the drug solution M to the outside of the cap <NUM> even in a case where the cap <NUM> slightly moves in the distal direction from the state of <FIG> and where the proximal end surface <NUM> of the base portion <NUM> is apart from the distal end surface 20b of the nozzle portion <NUM>. Therefore, even with the configuration illustrated in <FIG>, similar operational effects as the configuration illustrated in <FIG> can be obtained.

The outer peripheral portion of the inner cap <NUM> illustrated in <FIG> includes an annular groove <NUM> recessed inward in the radial direction, and the annular protrusion <NUM> is engaged with the annular groove <NUM>. This configuration inhibits a relative movement in the axial direction between the inner cap <NUM> and the outer cap <NUM>. In this manner, the annular protrusion <NUM> also serves as a means for inhibiting axial relative movement of the inner cap <NUM> and the outer cap <NUM>, and a means for pressing the cylindrical wall <NUM> inward in the radial direction.

A cap 14a of a pre-filled syringe 10a according to a second embodiment of the present invention illustrated in <FIG> includes: the inner cap <NUM> (same as the inner cap <NUM> illustrated in <FIG> or the like) for sealing the distal end opening <NUM>; and a hollow cylindrical outer cap 36a for supporting the inner cap <NUM>. The barrel body <NUM> and the cap 14a constitute a syringe barrel 15a.

The outer cap 36a includes: a proximal end cylindrical portion <NUM> covering the cylindrical wall <NUM>; and a distal end cylindrical portion <NUM> provided on more toward the distal side than the proximal end cylindrical portion <NUM> and covering the base portion <NUM> of the inner cap <NUM>. The proximal end cylindrical portion <NUM> includes an engaging portion <NUM> engageable with the cylindrical wall <NUM> and provided on an inner peripheral surface 70a of the proximal end cylindrical portion <NUM>. In the mounted state where the cap 14a is mounted to the nozzle portion <NUM>, the cylindrical wall <NUM> of the inner cap <NUM> and the proximal end cylindrical portion <NUM> of the outer cap 36a are inserted into the annular groove <NUM>, and the inner peripheral surface of the cylindrical wall <NUM> is in close contact with the outer peripheral surface 20a of the nozzle portion <NUM>. In an unopened state of the cap 14a, the engaging portion <NUM> may be or need not be in contact with the cylindrical wall <NUM>.

The engaging portion <NUM> is an engaging protrusion 74a protruding inward in the radial direction from the inner peripheral surface 70a of the proximal end cylindrical portion <NUM> of the outer cap 36a. The engaging protrusions 74a extend in the circumferential direction and is provided in plurality at intervals in the circumferential direction. In the second embodiment, two engaging protrusions 74a are provided at positions facing each other on the inner peripheral surface 70a of the proximal end cylindrical portion <NUM>. The cylindrical wall <NUM> includes an engaged portion <NUM> engageable with the engaging protrusion 74a. The engaged portion <NUM> is a proximal end surface 44a of the cylindrical wall <NUM>.

As illustrated in <FIG>, that is, in a cross section <NUM>° axially shifted from the pre-filled syringe 10a illustrated in <FIG>, the inner peripheral surface 72a of the distal end cylindrical portion <NUM> of the outer cap 36a includes two arcuate protrusions <NUM> protruding from the inner peripheral surface 72a inward in the radial direction and engaging with the annular groove <NUM> of the inner cap <NUM> at intervals in the circumferential direction. The arcuate protrusion <NUM> is a protrusion extending in an arc shape in the circumferential direction and provided in place of the above-described annular protrusion <NUM> (<FIG>). The two engaging protrusions 74a and the two arcuate protrusions <NUM> are disposed <NUM>° shifted with each other in the circumferential direction so as not to form an undercut at the time of injection molding.

Meanwhile, there is a case, in the above-described pre-filled syringe <NUM> (<FIG>), where the degree of contact between the outer peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface of the inner cap <NUM> might become too high, leading to an occurrence of a pseudo fixed (adhered) state between the inner peripheral surface 20a of the nozzle portion <NUM> and the inner peripheral surface of the inner cap <NUM>. Pseudo fixation (adhesion) is a state where two members adhere to each other and a predetermined level of force or more is required to release the adhesion. In this case, in removing the cap 14a in the mounted state from the barrel body <NUM>, the cylindrical wall <NUM> of the inner cap <NUM> expands and causes the cap 14a to be removed after full expansion of the cylindrical wall <NUM>, leading to spouting out of the drug solution M from the inside of the barrel body <NUM>. Spouting out of the drug solution M might decrease the liquid amount and cause the drug solution M to be attached to the surroundings.

In contrast, according to the pre-filled syringe 10a, when the cap 14a in the mounted state is removed from the barrel body <NUM>, the engagement between the engaging portion <NUM> and the cylindrical wall <NUM> allows the moving force of the outer cap 36a in moving toward the lock adapter <NUM> to be transmitted directly to the cylindrical wall <NUM>. That is, when the cylindrical wall <NUM> expands at the time of opening the cap 14a to move with the outer cap 36a alone, the engaging protrusion 74a of the outer cap 36a is caught on the inner cap <NUM>.

According to this configuration, it is possible to move the inner cap <NUM> together with the movement of the outer cap 36a at removal of the cap 14a from the barrel body <NUM> even when the inner peripheral surface of the cylindrical wall <NUM> of the inner cap <NUM> is pseudo fixed (adhered) to the outer peripheral surface 20a of the nozzle portion <NUM>, making it possible to restrain (prevent) expansion of the cylindrical wall <NUM>. This makes is possible to prevent the drug solution M from spouting out at the time of opening the cap 14a.

Particularly, in the pre-filled syringe 10a, the engaging portion <NUM> is the engaging protrusion 74a protruding inward in the radial direction from the inner peripheral surface 70a of the proximal end cylindrical portion <NUM> of the outer cap 36a, and the cylindrical wall <NUM> includes the engaged portion <NUM> to be engaged with the engaging protrusion 74a. At removal of the cap 14a in the mounted state from the barrel body <NUM>, engagement of the engaging protrusion 74a with the engaged portion <NUM> from the proximal side allows the moving force to be transmitted directly to the cylindrical wall <NUM>. This configuration enables acquisition of a further satisfactory engaging force, making it possible to further reliably move the inner cap <NUM> together with the movement of the outer cap 36a when the cap 14a is removed from the barrel body <NUM>.

In the pre-filled syringe 10a, the engaged portion <NUM> is the proximal end surface 44a of the cylindrical wall <NUM>. With this configuration, the proximal end surface 44a of the cylindrical wall <NUM> is pressed in the distal direction by the engaging portion <NUM> when the cap 14a is removed from the barrel body <NUM>, making it possible to move the entire cylindrical wall <NUM> integrally with the outer cap 36a. In addition, the proximal end surface 44a of the cylindrical wall <NUM> can be utilized as it is as the engaged portion <NUM>, making it possible to avoid complication of the structure of the cylindrical wall <NUM> due to the presence of the engaged portion <NUM>.

The barrel body <NUM> is formed of a cyclic olefin polymer or a cyclic olefin copolymer. With the barrel body <NUM> formed of a cyclic olefin polymer or a cyclic olefin copolymer, the inner cap <NUM> is likely to be pseudo fixed to the nozzle portion <NUM>. Accordingly, the present invention capable of restraining expansion of the cylindrical wall <NUM> at the time of opening the cap 14a is particularly useful. With the inner cap <NUM> formed from butyl rubber, the inner cap <NUM> is further likely to be pseudo fixed to the nozzle portion <NUM>, making the present invention further useful.

Sterilization treatment (for example, high pressure steam sterilization) involving a thermal load onto the syringe barrel 15a has been applied on the syringe barrel 15a in the mounted state. With application of sterilization treatment involving a thermal load, the inner cap <NUM> is further likely to be pseudo fixed to the nozzle portion <NUM>. Accordingly, the present invention capable of restraining expansion of the cylindrical wall <NUM> at the time of opening the cap 14a is particularly useful.

A cap 14b of a pre-filled syringe 10b according to a third embodiment of the present invention illustrated in <FIG> includes: the inner cap <NUM> (same as the inner cap <NUM> illustrated in <FIG> or the like) for sealing the distal end opening <NUM>; and a hollow cylindrical outer cap 36b for supporting the inner cap <NUM>. The barrel body <NUM> and the cap 14b constitute a syringe barrel 15b.

The proximal end cylindrical portion <NUM> of the outer cap 36b includes an engaging portion <NUM> engageable with the cylindrical wall <NUM> and provided on the inner peripheral surface 70a of the proximal end cylindrical portion <NUM>. The engaging portion <NUM> is an engaging protrusion 80a protruding inward in the radial direction from the inner peripheral surface 70a of the proximal end cylindrical portion <NUM> of the outer cap 36a. The engaging protrusion 80a is an annular protrusion extending over the entire circumference in the circumferential direction.

The cylindrical wall <NUM> includes an engaged portion <NUM> engageable with the engaging protrusion 80a. The engaged portion <NUM> is an engaged protrusion 82a protruding outward in the radial direction from the outer peripheral surface of the cylindrical wall <NUM> and is provided on more toward the distal side than the engaging protrusion 74a.

In <FIG>, the enlarged diameter portion <NUM> constitutes the engaged protrusion 82a. Note that the engaged protrusion 82a may be provided on more proximal side than the enlarged diameter portion <NUM>, separately from the enlarged diameter portion <NUM>. When the engaged protrusion 82a is provided separately from the enlarged diameter portion <NUM>, the engaging portion <NUM> (engaging protrusion 80a) is provided on more toward the proximal side than the position illustrated in <FIG>.

According to the pre-filled syringe 10b, when the cap 14b in the mounted state is removed from the barrel body <NUM>, engagement between the engaging protrusion 80a and the engaged protrusion 82a allows the moving force of the outer cap 36b in moving toward the lock adapter <NUM> to be transmitted directly to the cylindrical wall <NUM>. That is, when the cylindrical wall <NUM> expands at the time of opening the cap 14b to move with the outer cap 36b alone, the engaging protrusion 80a of the outer cap 36b is caught on the engaged protrusion 82a of the inner cap <NUM> (cylindrical wall <NUM>). This can minimize the expansion of the cylindrical wall <NUM>, making it possible to prevent the drug solution M from spouting out at the time of opening the cap 14b.

A cap 14c of a pre-filled syringe 10c according to a fourth embodiment of the present invention illustrated in <FIG> includes: the inner cap <NUM> (same as the inner cap <NUM> illustrated in <FIG> or the like) for sealing the distal end opening <NUM>; and a hollow cylindrical outer cap 36c for supporting the inner cap <NUM>. The barrel body <NUM> and the cap 14c constitute a syringe barrel 15c.

The proximal end cylindrical portion <NUM> of the outer cap 36c includes an engaging portion <NUM> engageable with the cylindrical wall <NUM> and provided on the inner peripheral surface 70a of the proximal end cylindrical portion <NUM>. The engaging portion <NUM> is a plurality of engaging ribs 86a extending along the axis of the proximal end cylindrical portion <NUM>. As illustrated in <FIG>, the plurality of engaging ribs 86a is arranged at intervals in the circumferential direction.

In <FIG>, the cylindrical wall <NUM> includes an engaged portion <NUM> engaged with the plurality of engaging ribs 86a, on the outer peripheral surface of the cylindrical wall <NUM>. The plurality of engaging ribs 86a bites into the engaged portion <NUM>. In <FIG>, the enlarged diameter portion <NUM> constitutes the engaged portion <NUM>. Note that the engaged portion <NUM> may be provided on more proximal side than the enlarged diameter portion <NUM>, separately from the enlarged diameter portion <NUM>. An engaged rib meshed with the engaged rib 86a may be provided on the outer peripheral surface of the cylindrical wall <NUM>. In this case, the engaged rib extends along the axis of the cylindrical wall <NUM> and is provided in plurality at intervals in the circumferential direction.

According to the pre-filled syringe 10c, when the outer cap 36c is rotated with respect to the lock adapter <NUM> to remove the cap 14c in the mounted state from the barrel body <NUM>, engagement of the plurality of engaging ribs 86a with the engaged portion <NUM> (outer peripheral surface of the cylindrical wall <NUM>) allows the moving force of the outer cap 36c in rotationally moving with respect to the lock adapter <NUM> to be transmitted directly to the cylindrical wall <NUM>. This rotates the cylindrical wall <NUM> of the inner cap <NUM> simultaneously with the outer cap 36c when the cap 14c is removed from the barrel body <NUM>. Accordingly, moving the cylindrical wall <NUM> along with the movement of the outer cap 36c makes it possible to prevent expansion of the cylindrical wall <NUM>. This makes is possible to prevent the drug solution M from spouting out at the time of opening the cap 14c.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the scope of the present invention.

Claim 1:
A syringe barrel (<NUM>, 15a to 15c) comprising:
a barrel body (<NUM>) including a nozzle portion (<NUM>) at a distal end thereof; and
a cap (<NUM>, 14a to 14c) removably mounted to the nozzle portion (<NUM>) and configured to seal a distal end opening (<NUM>) of the nozzle portion (<NUM>),
wherein the cap (<NUM>, 14a to 14c) comprises:
an inner cap (<NUM>) formed of an elastic material and configured to come in liquid tight close contact with the nozzle portion (<NUM>) in a mounted state in which the cap (<NUM>, 14a to 14c) is mounted to the nozzle portion (<NUM>), and
a cylindrical outer cap (<NUM>, 36a to 36c) formed of a material having higher hardness than the inner cap (<NUM>) and fixed around the inner cap (<NUM>),
wherein the inner cap (<NUM>) comprises:
a base portion (<NUM>); and
a cylindrical wall (<NUM>) extending from the base portion (<NUM>) in a proximal direction and surrounding the nozzle portion (<NUM>),
characterized in that the cylindrical wall (<NUM>) is configured to be sandwiched in a compressed state between an outer peripheral surface (20a) of the nozzle portion (<NUM>) and an inner peripheral surface (<NUM>) of the outer cap (<NUM>, 36a to 36c) in a state in which the base portion (<NUM>) is in close contact with a distal end surface (20b) of the nozzle portion (<NUM>) and in a state in which the base portion (<NUM>) is apart from the distal end surface (20b) of the nozzle portion (<NUM>) by a predetermined distance, such that the cylindrical wall (<NUM>) is in liquid tight close contact over a full circumference with the outer peripheral surface (20a) of the nozzle portion (<NUM>),
wherein an axial length of a compressed portion (<NUM>), which is a portion of the cylindrical wall portion (<NUM>) compressed between the nozzle portion (<NUM>) and the outer cap (<NUM>, 36a to 36c) in a state in which the base portion (<NUM>) is in close contact with the distal end surface (20b) of the nozzle portion (<NUM>), is <NUM> or more, and
wherein the axial length of the compressed portion (<NUM>) is shorter than an axial length of the cylindrical wall (<NUM>).