PREFILLED SYRINGE

• US 20120184920A1
• Filed: 03/30/2012
• Published: 07/19/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Okihara, Hitoshi, Watanabe, Hideo
• Granted Patent: US 9,101,720 B2
• Time in Patent Office: Days
• US Class Current: 604/222
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod

Abstract

A prefilled syringe has a gasket composed of a gasket body and a plunger-mounting member mounted. The plunger-mounting member has a distal part, spiral ribs formed on an outer surface of the distal part, a flange part, and a plunger-mounting part formed on an inner surface of a hollow part. The gasket body has a spiral screwing part which screws the spiral ribs and an accommodation part for accommodating a portion where the spiral ribs are formed. A plunger has a mounting distal part. The plunger-mounting part has a spiral concave portion and an engaging rib disposed at a side distal from the spiral concave portion. The mounting distal part of the plunger has a spiral projected portion capable of screwing the spiral concave portion and an engaging portion which engages the engaging rib of the plunger-mounting member.

Claims

1. A prefilled syringe comprising:

a prefilled syringe body including an outer cylinder possessing an opening at a distal end of the outer cylinder, a gasket slidably accommodated inside the outer cylinder, a sealing member sealing the opening at the distal end of the outer cylinder, and medicine accommodated inside a medicine accommodation part formed inside the outer cylinder;

a plunger mountable on the gasket and dismountable from the gasket;

the gasket comprising a tubular gasket body and a plunger-mounting member mounted on the gasket body, the tubular gasket body possessing a closed distal end, an open proximal end at which is located an opening, and a lumen part extending from the opening at the proximal end of the tubular gasket body toward the closed distal end;

the plunger-mounting member comprising;

a tubular body part possessing a hollow part penetrating through the tubular body part from one end of the tubular body part to an opposite end of the tubular body part, the tubular body part also possessing a distal side flange part having a distal end configured to press a proximal end surface of the gasket body;

a distal part projecting distally from the tubular body part and configured to be accommodated inside the lumen part of the gasket body, the distal part possessing an outer surface;

a spiral rib on the outer surface of the distal part of the plunger-mounting member;

a proximal side flange part at a proximal end of the tubular body part; and

a plunger-mounting part inside a proximal portion of the tubular body part and on which the plunger is mountable;

the tubular gasket body including a spiral screwing part on an inner surface of the tubular gasket body which surrounds the lumen part, the spiral screwing part being engageable with the spiral rib of the plunger-mounting member, the tubular gasket body also including an accommodation part disposed distally from the spiral screwing part of the lumen part for accommodating a portion of the distal part of the plunger-mounting member at which is located the spiral rib;

the plunger including a pressing part configured to press a proximal end surface of the proximal side flange part of the plunger-mounting member when mounting the plunger on the gasket, the plunger also including a mounting distal part projecting distally from the pressing part and configured to enter the plunger-mounting part of the plunger-mounting member;

the plunger-mounting part of the plunger-mounting member including a spiral concave portion and an engaging rib located at a position in a vicinity of the spiral concave portion and distal from the spiral concave portion;

the mounting distal part of the plunger having a spiral projected portion configured to screw engage the spiral concave portion of the plunger-mounting member, the mounting distal part of the plunger also having an engaging portion disposed in a vicinity of the spiral projected portion and at a distal side of the spiral projected portion which engages the engaging rib of the plunger-mounting member;

when the plunger-mounting member is mounted on the gasket body, the spiral rib is received in the accommodation part of the tubular gasket body and a distal end of the plunger-mounting member does not contact an inner surface of the tubular gasket body; and

when the plunger is mounted on the gasket, the mounting distal part of the plunger does not contact the inner surface of the tubular gasket body.

2. A prefilled syringe according to claim 1, wherein by inserting the mounting distal part of the plunger into a proximal portion of the plunger-mounting member and rotating the plunger, the spiral projected portion of the mounting distal part and the spiral concave portion of the plunger-mounting member progressively screw onto each other, and the engaging portion of the plunger proceeds and rides across the engaging rib of the plunger-mounting member, thus engaging the engaging rib.

3. A prefilled syringe according to claim 1, wherein when the engaging portion of the plunger engages the engaging rib of the plunger-mounting member, the spiral projected portion of the plunger and the spiral concave portion of the plunger-mounting member engage each other.

4. A prefilled syringe according to claim 1, wherein the engaging portion of the plunger comprises a plurality of distally extending claw portions on the distal part of the plunger and convex portions formed on outer surfaces of the claw portions;

and when the engaging portion of the plunger rides across the engaging rib of the plunger-mounting member, the convex portions engage the engaging rib.

5. A prefilled syringe according to claim 4, wherein the claw portions is disposed on substantially a common circumference.

6. A prefilled syringe according to claim 4, wherein outer surfaces of the claw portions are inclined surfaces which incline from distal ends of the claw portions to the convex portions.

7. A prefilled syringe according to claim 1, wherein the engaging rib of the plunger-mounting member is annular, and an inner surface of the engaging rib is a tapered surface which tapers such that a diameter of the engaging rib becomes gradually smaller toward a distal end of the engaging rib.

8. A prefilled syringe according to claim 1, wherein the tubular gasket body includes an annular projected part preventing removal of the plunger from the tubular gasket body, the annular projected part being located at a position in a vicinity of the spiral screwing part and distal from the spiral screwing part;

and the annular projected part has a guide portion for guiding the spiral rib formed on the body part of the plunger-mounting member to the accommodation part, when the spiral rib reaches the annular projected part owing to progress of screwing between the spiral rib of the body part of the plunger-mounting member and the spiral screwing part of the gasket body.

9. A prefilled syringe according to claim 8, wherein a rib of the annular projected part becomes gradually smaller toward the guide portion.

10. A prefilled syringe according to claim 1, wherein the spiral projected portion of the plunger is composed of two spiral lines, and the spiral concave portion of the plunger-mounting member is composed of two spiral lines corresponding to the two spiral lines of the spiral projected portion.

11. A prefilled syringe according to claim 1, wherein the plunger-mounting member includes a projected portion on a proximal end surface of a proximal portion of the spiral rib, the projected portion projecting toward the distal side flange part.

12. A prefilled syringe according to claim 1, wherein the plunger-mounting member includes a rib on the distal side flange part of the plunger-mounting member that projects toward the spiral rib.

13. A prefilled syringe comprising:

a prefilled syringe body including an outer cylinder possessing an opening at a distal end of the outer cylinder, a gasket slidably accommodated inside the outer cylinder so that a medicine accommodation part exists inside the outer cylinder distal of the gasket, a sealing member sealing the opening at the distal end of the outer cylinder, and medicine accommodated in the medicine accommodation part;

a plunger mountable on the gasket and dismountable from the gasket;

the gasket comprising a tubular gasket body connected to a plunger-mounting member, the tubular gasket body possessing a lumen which is open at a proximal end of the gasket body, the tubular gasket body possessing a proximal end surface;

the plunger-mounting member comprising;

a tubular body part possessing a hollow part opening to a proximal end of the tubular body part, the tubular body part also possessing a flange part having a distal end surface contacting the proximal end surface of the gasket body;

a distal part projecting distally from the tubular body part and extending distally beyond the flange, the distal part being positioned inside the lumen of the gasket body in spaced apart relation to an inner surface of the gasket body at a distal end of the lumen, the distal part possessing an outer surface along which extends a spiral rib; and

a plunger-mounting part inside a proximal portion of the tubular body part and on which the plunger is mountable;

the tubular gasket body including a spiral screwing part that screw-engages a spiral rib on the plunger-mounting member;

the tubular gasket body including an accommodation part at a distal end portion of the lumen in the tubular gasket body, the accommodation part accommodating a distal-most portion of the distal part at which is located a part of the spiral rib of the plunger-mounting member;

the plunger including a pressing part configured to press a proximal end surface of the plunger-mounting member when the plunger is mounted on the gasket, the plunger also including distally projecting mounting distal part positionable in the plunger-mounting part of the plunger-mounting member;

the plunger-mounting part of the plunger-mounting member including a spiral portion at a proximal portion of the hollow part plunger-mounting member, the plunger-mounting part also including an inwardly extending engaging rib located distal of the spiral portion;

the mounting distal part of the plunger having a spiral projected portion configured to screw engage the spiral portion of the plunger-mounting member, the mounting distal part of the plunger also having an engaging portion distal of the spiral projected portion and configured to engage the engaging rib of the plunger-mounting member; and

the distally projecting mounting distal part of the mounting distal part of the plunger engaging the inwardly extending engaging rib when the plunger is inserted into the hollow part plunger-mounting member and the spiral projected portion of the mounting distal part screw engages the spiral portion of the plunger-mounting part.

14. A prefilled syringe according to claim 13, wherein the engaging portion comprises a plurality of distally extending and circumferentially spaced apart claw portions which terminate in free ends that engage the inwardly extending engaging rib.

15. A prefilled syringe according to claim 13, wherein the engaging portion comprises a plurality of spaced apart claw portions which each terminate in an enlarged free end portion having an inclined surface which is inclined in a proximal direction.

16. A prefilled syringe according to claim 13, wherein the engaging rib of the plunger-mounting member is an annular rib possessing a tapered inner surface that tapers so that an inner diameter of the engaging rib becomes gradually smaller in a distal direction.

17. A prefilled syringe according to claim 13, wherein the tubular gasket body includes an annular projected part preventing removal of the plunger from the tubular gasket body, the annular projected part being located distal from the spiral screwing part.

18. A prefilled syringe according to claim 13, wherein the annular projected part includes a guide portion that guides the spiral rib formed on the body part of the plunger-mounting member toward the accommodation part.