Positive displacement stopper for a pre-filled syringe

Patent metadata

Field	Value
Publication number	US-9649444-B2
Application number	US-201313889539-A
Country	US
Kind code	B2
Filing date	May 8, 2013
Priority date	Jun 4, 2007
Publication date	May 16, 2017
Grant date	May 16, 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 said main body adjacent the closed front end. The core member includes a nose portion having a profile adapted to create a positive seal with an outlet opening of such syringe barrel.

First claim

The invention claimed is:

1. A method of positively displacing fluid from and preventing reflux within a syringe barrel, said method comprising the steps of:
(a) providing a stopper comprising a main body having a closed front end, a first body portion having a first diameter, a second body portion having a second diameter which is larger than said first diameter, and a core member integrally formed with said main body adjacent said closed front end, said core member including a nose portion, said stopper further comprising a shoulder extending around a perimeter of said first body portion of said main body, and a skirt extending about said first body portion of said main body, said skirt cooperating with said shoulder for trapping at least one air pocket therein;
(b) advancing the stopper through the syringe barrel until the nose portion of the core member contacts an outlet opening at the forward end of the syringe barrel;
(c) applying additional force to the stopper to compress the nose portion and increase the pressure within said at least one air pocket; and
(d) releasing the force on the stopper to release the seal between the nose portion and the outlet opening at the forward end of the syringe while maintaining the main body of the stopper in an advanced position relative to a starting position within the syringe barrel, such that the increased pressure within the at least one air pocket causes any trapped fluid to be expelled through said outlet opening.

2. The method of claim 1 , wherein said main body of said stopper includes an open rearward end with a plunger rod inserted within said open rearward end.

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

4. The method of claim 1 , wherein said core member is interconnected with said main body via a flexible membrane enabling the core member to move independently from the main body.

5. The method of claim 4 , wherein said step of applying additional force to said stopper to compress said nose portion causes said flexible membrane to stretch and said step of releasing the force releases said flexible membrane to cause any trapped fluid to be expelled through said outlet opening.

6. The method of claim 4 , wherein said stopper further includes a first rib on an outer surface of said skirt and at least a second rib extending radially outward around the second portion of said main body, wherein said step of applying additional force to said stopper advances the second rib within the syringe barrel and compresses the trapped air and increases the pressure within said air pockets; and wherein said second rib is maintained in an advanced position relative to the starting position within the syringe barrel when the force on the stopper is released, thereby maintaining the main body of the stopper fixed within the syringe barrel.

7. The method of claim 1 , wherein said main body comprises an inner surface having a curved contour from a side wall portion of said main body to said core member, said inner surface adapted for contact with a taper on a front forward end attachment portion of the plunger rod to apply a radial force to the syringe barrel upon the application of a forward force to the plunger rod.

8. A method of preventing reflux within a syringe barrel, said method comprising the steps of:
(a) providing a stopper comprising a main body defining an open rearward end and a closed front end, said open rearward end adapted to receive a front attachment member of a plunger rod therein, a core member integrally formed with said main body adjacent said closed front end, said core member including a nose portion, said stopper further comprising at least one rib extending radially outward around a perimeter of said main body and wherein said main body includes an inner surface adapted for contact with a taper on a front attachment member of a plunger rod, said inner surface of said main body and said taper cooperating together such that the stopper applies a radial force to the syringe barrel upon the application of a forward force to the plunger rod;
(b) inserting a front attachment member of a plunger rod within the open rearward end of said stopper;
(c) applying a force to said plunger rod to advance the stopper into the syringe barrel until the nose portion of the core member contacts an outlet opening at a front end of the syringe barrel forming a seal and trapping fluid from flowing out into the outlet opening;
(d) applying additional force to said plunger rod to compress at least a portion of said stopper, so as to advance the at least one rib within the syringe barrel and to compress the trapped fluid to form increased pressure;
(e) releasing the force on said plunger rod to release the seal between the nose portion and the outlet opening of the syringe barrel wherein friction force maintains said at least one rib in an advanced position relative to a starting position within the syringe barrel such that the increased pressure causes any trapped fluid to be pushed through said outlet opening.

9. The method of claim 8 , wherein said nose portion has a profile adapted to create a positive seal with an interior surface of the outlet opening of the syringe barrel.

10. The method of claim 8 , wherein said core member is interconnected with said main body via a flexible membrane enabling the core member to move independently from the main body.

11. The method of claim 10 , wherein said step of applying additional force to said plunger rod to compress said nose portion causes said flexible membrane to stretch and said step of releasing the force on the plunger rod releases this force on the flexible membrane to cause any trapped fluid to be pushed through said outlet opening.

12. The method of claim 8 , wherein said stopper includes at least one forward extending skirt extending from a front end of said main body and wherein said step of applying a force to advance the stopper into the syringe barrel causes said skirt to deflect inward with respect to the stopper main body and to contact the stopper main body, thereby trapping fluid within a space between said skirt and said main body.

13. The method of claim 12 , wherein the main body further includes a shoulder extending around a perimeter of the main body, such that the skirt extends inwardly and contacts the shoulder, thereby establishing the space between the skirt and the main body.

14. The method of claim 8 , wherein said main body comprises an inner surface having a curved contour from a side wall portion of said main body to said core member, said inner surface adapted for contact with the taper on the front attachment member of the plunger rod to apply a radial force to the syringe barrel upon the application of a forward force to the plunger rod.

Assignees

• Becton Dickinson Co

Inventors

• Schiller Eric
• Quinn Michael Vincent
• Torres Johanna
• Guan E
• Economou Anthony
• Ju Gang

Classifications

• A61M5/31513 Primary

  Piston constructions to improve sealing or sliding · CPC title

• A61M2005/31523

  for reducing reflux · CPC title

• A61M5/31511

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

• A61M2005/31521

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

• A61M5/31515

  Connection of piston with piston rod · CPC title