WO2000069492A1

WO2000069492A1 - Safety seal for syringe and method of sealing same

Info

Publication number: WO2000069492A1
Application number: PCT/US2000/012143
Authority: WO
Inventors: Joel Schoenfeld
Original assignee: Joel Schoenfeld
Priority date: 1999-05-14
Filing date: 2000-05-04
Publication date: 2000-11-23
Also published as: AU4819200A

Abstract

A tamper-evident seal (40) for a hypodermic syringe and a method of sealing a syringe is provided. The seal (40) includes a band of film disposed around a portion of the plunger (8) and the proximal rear end of the barrel (20), perferably in a sufficiently snug fit to immobilize the plunger (8) in the barrel (20) and prevent it from moving while the seal is intact. The seal (40) may be provided with perforations (50) to facilitate the removal of the seal (40) when a person seeks to use the syringe. A tab (51) may be provided extending from the film to provide a finger grip, and a string (150) may be formed integrally with the film also to facilitate removal.

Description

SAPETY SEAL FOR SYRINGE AND METHOD OF SEALING SAME RELATED APPLICATIONS This application claims priority from U.S. Provisional Patent Application No. 60/134,147. BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to hypodermic syringes and more specifically relates to a method and seal for readily showing if a hypodermic syringe has been previously used. The invention also relates to a method and seal for improving and better guaranteeing and maintaining the sterility of a syringe.

Description of the Related Art

Previous attempts have been made at creating methods and devices for revealing when a syringe has been tampered with or re-used. U.S. Patent No. 5,645,824 to Lim, the teachings of which are incorporated herein by reference, describes a color changing reagent composition for coating onto syringe needles and other needle containing medical devices which, upon contact with such bodily fluids as blood, mucous, saliva, and semen, causes the composition coated needle to change in color to signal a prior use and contamination with a possibly infected bodily fluid. After the coated needle comes in contact with a bodily fluid having a catalyst it, upon oxidation, changes from being in a colorless state to having a visually detectable color. The Lim system is intended to reduce both the mistaken or even intentional re-use of used needles. However, Lim teaches coating only the needle of the syringe with the reagent formula; there is no indicator in Lim for showing that the rest of the syringe, i.e., the barrel and plunger, have not been previously used. U.S. Patent No. 4,030,498 to Tompkins, the teachings of which are incorporated herein by reference, teaches a contamination-resistant syringe. It is provided with two sealing rings axially spaced from each other on the plunger. The sealing rings are prevented from sweeping the same area and there is no communication between the chamber defined between the two sealing rings and the discharge area forward of the inner sealing ring. In this manner, contamination which might enter from the rear of the barrel will be prevented from contact with the inner sealing ring. However, Tompkins does not prevent the syringe from being used repeatedly, it merely prevents contaminants from entering the bore of the barrel from the rear. Conventional syringes suffer from a lack of an ability to communicate to the user an indication that the syringe has never been used before and that the purity of the barrel and its contents has not been compromised.

SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide a method of indicating to a potential user if a syringe has been used before.

It is another object of the invention to provide a method and seal for indicating if a syringe has been previously used.

It is another object of the invention to provide a method and seal for ensuring that a syringe has not been used before and for preventing a syringe from being used more than once.

It is another object of the invention to provide a method and seal for protecting the contents of a syringe from contamination when stored. It is another object of the invention to provide a method and seal for prolonging sanitary condition and the shelf life of a syringe in storage.

The above and other objects are satisfied by the invention which includes a method and a seal for sealing a syringe. A band or ring of film is provided around the plunger and the top, proximal, rear end of the barrel, immobilizing the plunger and sealing the rear end of the barrel from the ambient environment. If one wishes to use the syringe thus sealed, the seal must first be broken to manipulate the plunger. In this way, if the seal is damaged or missing, the user knows that the syringe may have been used previously or that the contents of the syringe may have been compromised. The band or ring of film is preferably made of heat-shrinkable plastic and is designed to be destructible or removable so that one may remove the seal with ease and thereafter use the syringe. That the seal is made destructible or removable makes it more difficult to remove the seal, use the syringe, and then replace the seal to mask or hide the previous use of the syringe. In this way, the seal provides a clear indication that the syringe is unused and sterility not compromised.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view depicting a conventional hypodermic syringe provided with a seal according to the invention. Fig. 2 is a partial enlarged sectional view depicting a conventional hypodermic syringe provided with an alternate embodiment seal according to the invention.

Fig. 3 is a partial enlarged sectional view depicting a conventional hypodermic syringe provided with another alternate embodiment seal according to the invention. DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENT Description of the invention will now be given with reference to the attached Figs. 1- 3. A syringe 5 includes plunger 8 and barrel 20. Plunger 8 includes shaft 10 and flange 12 disposed on a proximal end of shaft 10. A sealed piston head 14 is provided on a distal end of plunger 8. Plunger 8 is reciprocatably disposed in bore 24 of barrel 20. A proximal end of barrel 20 includes a finger grip or flange 22. The distal end of barrel 20 includes a needle mount 28 and, disposed on the needle mount 28, a hollow needle 30 having tip 31. A needle cover 32 may be provided over needle 30 for safety reasons to prevent accidental needle sticks and to prevent damage to the needle 30. Medicine or similar contents 100 is disposable in bore 24; when one pushes down on plunger 8, the piston forces contents 100 out of bore 24 via opening 26. The contents 100 are ejected out of needle 30 and into the patient.

The inventive method adds a seal 40 in the preferred form of a band of plastic film formed around the top or proximal portion of barrel 20 (including flange 22) and shaft 10 of plunger 8. The provision of seal 40 around the syringe in this location serves several purposes. First, it stabilizes the plunger 8 by keeping it fixed with respect to barrel 20. By keeping the parts of the syringe 5 fixed relative to each other, less damage is caused during shipping. Second, it seals any gap that may exist between the shaft 10 of plunger 8 and the inner wall of bore 24, thus preventing foreign material from entering into bore 24 and possibly contaminating either contents 100 or the interior of bore 24. It also prevents ambient air from entering bore 24 (assuming the seal 40 is airtight) and prevents the oxidation of contents 100, should the contents be oxidizable. Third, seal 40 provides readily discernible visual evidence that syringe 5 has been neither tampered with nor previously used.

Seal 40 is preferably made from readily destructible heat-shrinkable plastic so that a user may easily remove the seal to use the syringe. A thin band of plastic shrink-wrapped around the upper region of barrel 20 and at least part of shaft 10 of plunger 8 is contemplated. In an alternate embodiment, the seal extends over flange 12. However, many elderly and infirm individuals might have difficulty tearing seal 40 off of syringe 5. Consequently, it is optionally desirable to provide a means for facilitating the removal of the seal. For example, as shown in Fig. 2, one optional structural feature to be added to seal 40' are lines of perforations 50. Perforations 50 may be added to the film by any conventional method, including puncturing, ultrasonics, heat, etc. The user would be directed to tear the seal 40' at the perforations 50 in order to remove the seal for use of the syringe. A tab 51 may also be optionally provided to facilitate removal of the seal. Perforations 50 are shown being parallel to the longitudinal axis of syringe 5, however any configuration of perforations is contemplated; for example, perforations at an angle to the axis of the syringe, a spiral-shaped perforation, etc. Further, two lines of perforations 50 are shown, however the seal 40' need only be provided with one line of perforations for it to be more easily removed. As another possibility, as shown in Fig. 3, a string or cord 150 may be formed integral with seal 40". When one wishes to use syringe 5, the user would pull on string 150 and thereby rend seal

40" for easy removal.

The invention is not limited to the above description but rather is defined by the claims appearing hereinbelow. Modifications to the above description that include that which is known in the art are well within the scope of the contemplated invention.

Claims

What is claimed is:

1. A seal for a hypodermic syringe, the syringe having a barrel and a plunger slidably disposed inside the barrel, comprising: a band of film disposed around at least a portion of the plunger and the proximal end of the barrel from which the plunger extends.

2. A seal according to Claim 1, wherein said film seals the proximal end of the barrel off from the ambient environment.

3. A seal according to Claim 1, wherein said film is snugly disposed around said at least a portion of said plunger and immobilizes the plunger within the barrel.

4. A seal according to Claim 1, wherein said film is provided with perforations.

5. A seal according to Claim 4, wherein said perforations extend from a proximal end of said seal in a direction towards a distal end of said seal and are arranged in at least one line parallel to the longitudinal axis of the syringe.

6. A seal according to Claim 1, wherein said film further comprises a tab extending from said film, wherein said tab provides a finger grip to facilitate tearing of said film.

7. A seal according to Claim 5, wherein said film further comprises a tab extending from said film, wherein said tab provides a finger grip to facilitate tearing of said film along said perforations.

8. A seal according to Claim 4, wherein said perforations extend from a proximal end of said seal in a direction towards a distal end of said seal and are arranged in at least one line in a spiral pattern.

9. A seal according to Claim 8, wherein said film is made from heat-shrinkable plastic.

10. A seal according to Claim 9, said film further comprising a string formed integrally with said film disposed in proximity to said line of said perforations, an end of said string extending beyond an edge of said film.

11. A seal according to Claim 4, wherein said film is made from heat-shrinkable plastic.

12. A seal according to Claim 11, said film further comprising a string formed integrally with said film disposed in proximity to said line of said perforations, an end of said string extending beyond an edge of said film.

13. A seal according to Claim 1, wherein said film is made from heat-shrinkable plastic.

14. A seal according to Claim 13, said film further comprising a string formed integrally with said film, an end of said string extending beyond an edge of said film.

15. A tamper-evident hypodermic syringe, comprising: a barrel having a longitudinal bore; a plunger slidably disposed in said barrel and extending from a proximal end of said barrel; and a band of film disposed around at least a portion of said plunger and said proximal end of said barrel, wherein said film seals said proximal end of said barrel off from the ambient environment.

16. A tamper-evident hypodermic syringe according to Claim 15, wherein said film is provided with perforations to facilitate selective removal of said film.

17. A tamper-evident hypodermic syringe according to Claim 15, wherein said film further comprises a tab extending from said film, wherein said tab provides a finger grip to facilitate removal of said film.

18. A tamper-evident hypodermic syringe according to Claim 15, said film further comprising a string formed integrally with said film, an end of said string extending beyond the edge of said film.

19. A method of sealing a hypodermic syringe, the syringe having a barrel and a plunger slidably disposed in a longitudinal bore of the barrel, comprising the steps of: providing a band of film around at least a portion of the plunger and the proximal end of the barrel.

20. A method of sealing a hypodermic syringe according to Claim 19, further comprising the step of heat- shrinking the film around the plunger and the barrel.

21. A method of sealing a hypodermic syringe according to Claim 20, further comprising providing a visual indication that said syringe has not been used comprising the step of sealing off the proximal end of the barrel from the ambient environment with the band of film.

22. A method of sealing a hypodermic syringe according to Claim 19, further comprising the step of forming perforations in the film to facilitate selective removal thereof.

23. A method of sealing a hypodermic syringe according to Claim 19, further comprising the step of disposing a string integrally with the band of film with an end of the string extending beyond the edge of the film.