Stoppers used in pre-filled syringes

Patent metadata

Field	Value
Publication number	US-9592346-B2
Application number	US-201414224722-A
Country	US
Kind code	B2
Filing date	Mar 25, 2014
Priority date	Jun 4, 2007
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A stopper adapted for attachment with a plunger rod for use within a syringe barrel is disclosed. The stopper includes a main body defining an open rearward end and a closed front end. The open rearward end is adapted to receive a front forward end attachment portion of the plunger rod. The stopper also includes a core member integrally formed with the main body adjacent the closed front end. The core member includes a nose portion having a conical tip configured for entering an outlet opening of the syringe barrel. The closed front end of the stopper has a profile configured to cooperate with an internal surface of the syringe barrel wall to prevent reflux and reduce dead space within the barrel.

First claim

The invention claimed is:

1. A stopper adapted for attachment with a plunger rod for use within a syringe barrel, said stopper comprising:
(a) a main body defining an open rearward end and a closed front end, said open rearward end adapted to receive a front forward end attachment portion of such plunger rod;
(b) a core member integrally formed with said main body adjacent said closed front end, said core member including a nose portion and a stopper center post protruding from an interior of the core member toward the open rearward end, said stopper center post including a back core portion adapted for contact with said front forward end attachment portion of the plunger rod;
(c) at least one rib extending radially outward around a perimeter of said main body for forming an active seal with such syringe barrel; and
(d) an inward shoulder portion on an inner surface of said main body, said inward shoulder portion adapted for contact at a contact point with a taper on a forward end of the plunger rod,
wherein contact of said inward shoulder portion with said taper causes the stopper to apply a radial force to said at least one rib and the syringe barrel upon the application of a forward force to the plunger rod, and
wherein said inward shoulder portion includes a first cylindrical wall portion extending from the closed front end of said main body to the contact point, said first cylindrical wall portion having a substantially flat surface profile that is substantially uniform and non-tapered along its longitudinal length.

2. The stopper of claim 1 , wherein the longitudinal length of the first cylindrical wall portion extends between the closed front end to the contact point of the inward shoulder portion of the main body and the taper on the forward end of the plunger rod.

3. The stopper of claim 1 , wherein said inward shoulder portion further includes a second cylindrical wall portion extending toward the open rearward end of said main body and a sloped portion extending between the first cylindrical wall portion and the second cylindrical wall portion.

4. The stopper of claim 3 , wherein the sloped portion is configured for contacting the taper on the forward end of the plunger rod at the contact point.

5. The stopper of claim 1 , wherein said nose portion of the stopper has a profile adapted to create a positive seal with an outlet opening of such syringe barrel.

6. The stopper of claim 5 , wherein the nose portion of the stopper is configured to seat against the outlet opening and seal this opening without deformation of the nose portion.

7. The stopper of claim 1 , wherein said core member includes a front portion, a back portion, and a central portion positioned between said front and back portions, said front portion extending beyond the closed front end of said main body and said central portion is interconnected with said main body via a flexible membrane extending between said core member and said main body.

8. The stopper of claim 1 , wherein said main body includes at least one forward extending skirt extending from the closed front end of said main body wherein said skirt is adapted for creating a positive pressure chamber therein.

9. The stopper of claim 1 , wherein said core member includes a back portion and wherein at least one of said back portion of said core member and an inner surface of said closed front end includes at least one groove formed therein.

10. The stopper of claim 9 , wherein at least one of said back portion of said core member and the inner surface of said closed front end includes a plurality of grooves formed therein.

11. The stopper of claim 9 , wherein at least one of said back portion of said core member and said inner surface of said closed front end includes stopper material adapted for contacting the front forward end attachment portion of the plunger rod upon an application of forward force to the plunger rod.

12. The stopper of claim 11 , wherein the stopper material adapted for contacting the front forward end attachment portion of the plunger rod is configured to prevent the plunger rod and the taper of the rod from slipping forward into a stopper interior and reduces an amount of pressure applied to the back core portion.

13. A plunger rod and stopper assembly adapted for use with a syringe barrel, said assembly comprising:
(a) a plunger rod having a front attachment end and a back end and extending along a longitudinal axis, said front attachment end including a taper and a front flange extending therefrom;
(b) a stopper having a main body defining an open rearward end, a closed front end, and a core member integrally formed with said main body adjacent said closed front end, said core member including a stopper center post protruding from an interior of the core member toward the open rearward end, said stopper center post including a back core portion adapted for contact with said front attachment end of the plunger rod, said open rearward end adapted for receiving said front attachment end of said plunger rod;
(c) a taper formed on an inner surface of said main body adapted for contact with the front attachment end of such plunger rod; and
(d) an open space defined by the inner surface of the main body, a portion of said core member, and said taper on the inner surface of said main body,
wherein said front flange extending from said front attachment end of said plunger rod extends into said open space to limit longitudinal travel of the plunger rod relative to the stopper.

14. The plunger rod and stopper assembly of claim 13 , wherein said open rearward end of said stopper is defined by an inside wall surface and wherein said open rearward end is adapted for receiving said front attachment end of said plunger rod and locking said plunger rod within said stopper.

15. The plunger rod and stopper assembly of claim 13 , including at least one rib extending radially outward around a perimeter of said main body for forming an active seal with the syringe barrel.

16. The plunger rod and stopper assembly of claim 15 , wherein said taper on said inner surface of said main body and said taper of said front attachment end form an active seal surface for cooperating together causing said stopper to apply a radial force to said at least one rib and the syringe barrel upon the application of a forward force to the plunger rod.

Assignees

• Becton Dickinson Co

Inventors

• Quinn Michael Vincent
• Schiller Eric
• Ju Gang
• Guan E

Classifications

• A61M5/31511

  Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence) · CPC title

• A61M5/31513 Primary

  Piston constructions to improve sealing or sliding · CPC title

• A61M2005/31521

  Pistons with a forward extending skirt at their front end · CPC title

• A61M2005/31523

  for reducing reflux · CPC title

• A61M5/31515

  Connection of piston with piston rod · CPC title