WO2003047669A1

WO2003047669A1 - Syringe

Info

Publication number: WO2003047669A1
Application number: PCT/GB2002/005421
Authority: WO
Inventors: Marc Koska
Original assignee: Star Syringe Limited
Priority date: 2001-11-30
Filing date: 2002-11-28
Publication date: 2003-06-12
Also published as: GB0128651D0; AU2002349142A1

Abstract

A reconstitution syringe having a barrel (24) of plastic material with an integrally-formed hollow needle (23). The needle (23) has a piercing point (27), a passage (28) connecting the barrel (24) to an aperture (29) allowing fluid flow into and out of the needle (23), and reinforcement means (30, 31, 32) at least in the region of the aperture (29). In the syringe according to the invention the barrel (24) and needle (23) are formed as a single item, so that the syringe is easy and inexpensive to make. It is also easy to use, as it does not require a separate needle (9) to be attached, and safe, as the plastics needle (23) is less likely to cause puncture wounds.

Description

SYRINGE

This invention relates to a reconstitution syringe.

When certain substances such as vaccines are injected into the human or animal body the injectate is reconstituted from powder by adding a sterile liquid.

A reconstitution syringe is used to add the liquid to the powder. This syringe must therefore be able to break a rubber (or similar) seal on a container of the sterile liquid, draw up a given amount of liquid, and then add it to the powder. Conventionally, an ordinary injection syringe with a metal needle attached to the barrel by a luer slip connection is used as the reconstitution syringe. However, while such syringes are readily available and work well, it is not essential to use a metal needle because it is not necessary to pierce skin. In this situation, the metal needle in fact puts the user at unnecessary risk of puncture wounds and the like. In order to overcome this risk, it is known for a needle of hard plastics material to replace the metal needle. However, such a needle is expensive, and may not be readily available.

According to the present invention, a reconstitution syringe has a barrel of plastics material with an integrally-formed hollow needle, the needle having a piercing point, a passage connecting the barrel to an aperture allowing fluid flow into and out of the needle, and reinforcement means at least in the region of the aperture.

In the syringe according to the invention the barrel and needle are formed as a single item, so that the syringe is easy and inexpensive to make. It is also easy to use, as it does not require a separate needle to be attached, and safe, as the plastics needle is less likely to cause puncture wounds. The design of the needle, in particular the reinforcement means, enables the syringe to be made in the conventional softer plastics, such as polypropylene, while ensuring that the needle has the rigidity necessary for piercing the seal. This means that it is easy to modify the design of an existing syringe to incorporate the integral needle of the reconstitution syringe.

Preferably the needle has a closed conical end formed with the piercing point. The aperture is then formed in the conical part. The aperture is preferably circular, but may be elliptical. The size of the aperture and the angle at which the aperture meets the passage is chosen for optimum fluid flow. Preferably, the angle between the aperture and the passage is less than 90° .

The reinforcement means conveniently comprises a longitudinal ridge on each side of the aperture. Further longitudinal ridges may also be provided, to ensure that the needle has the required rigidity. The further longitudinal ridges may be on a cylindrical portion of the needle or on the conical part.

Preferably, the part of the needle which contains the aperture is concave. This assists fluid flow through the aperture, and also assists in providing rigidity at the end of the needle, particularly when the aperture is in the conical end.

Conveniently, support ribs are provided at the junction of the barrel and the needle.

The syringe itself, that is, the barrel and the plunger, may be of any known type. It is particularly useful if the syringe is of the autodestruct type, where it can be used once only. This prevents the use of the syringe again for other purposes, which can be a problem where syringes are in short supply and/or are expensive. While it would be difficult to use this reconstitution syringe for normal injections, because the needle is not designed to pierce skin, the use of an autodestruct syringe prevents re-use.

An embodiment of the invention is illustrated, by way of example, in the accompanying drawings, in which:

Figure 1 is a side view of a conventional syringe with a detachable needle;

Figure 2 is a side view of part of a syringe according to the invention, showing the barrel;

Figure 3 is an end view of the needle of Figure 2; and

Figure 4 is an enlarged section along the line 4-4 of Figure 2.

Figure 1 shows a known injection syringe 1 comprising a barrel 2 in which a plunger 3 works. The barrel 2 is moulded from plastics material, such as polypropylene, and has a cylindrical inner surface (not shown) , an open proximal end 4 with a gripping flange 5, and a distal end 6 with a hollow distal projection 7 having a liquid outlet 8. A metal hypodermic needle 9 is attached to the projection 7, which has a conical external surface 10, by a hub 11.

The hub 11 is open-ended, hollow and injection-moulded from plastics. A distal part 12 has a bore of small diameter to receive the hypodermic needle 9. The needle 9 is glued in place by adhesive 13. A proximal part needle 9. The bore is adapted to receive the conical external surface 10 of the barrel projection 7, the surface 10 being complementary to the bore to form a luer slip arrangement.

The plunger 3 is also of plastics material, with a seal (not shown) at its distal end. Movement of the plunger 3 into the barrel 2 will expel the barrel contents through the needle, while withdrawal of the plunger 3 from the barrel 2 will draw liquid into the barrel 2 through the needle 9.

The known syringe 1 of Figure 1 may be used as a reconstitution syringe, with the needle 9 being used to puncture a rubber or similar seal on a container (not shown) of sterile liquid. The plunger 3 is then withdrawn from the barrel 2 to draw the liquid into the barrel 2, and can be dispensed from the needle by pushing the plunger into the barrel to be added to a vaccine powder, to reconstitute a vaccine for injection.

However, it is not essential to use a metal needle, as it is not necessary for the needle to pierce skin, and indeed a metal needle may pose unnecessary risks of puncture wounds for the user.

The reconstitution syringe 21 according to the invention, and shown in Figures 2 to 4, overcomes this problem.

Figure 2 shows the distal part of the syringe barrel; the remainder of the barrel and the plunger are the same as those of Figure 1.

The syringe 21 in Figure 2 is also injection-moulded from polypropylene, but at its distal end the projection 7 is replaced by a hollow needle 23 integral with the barrel body 24. The needle 23 has a cylindrical portion

25 adjacent the barrel body 24, and terminates at its distal end in a closed conical tip 26 with a piercing point 27. A passage 28 in the cylindrical portion 25 connects the inside of the barrel 22 to an aperture 29 formed in the conical tip 26. Liquid can therefore flow into and out of the barrel 22 through the aperture 29 and the passage 28.

The aperture 29 is elliptical, and inclined to the passage 28 for optimum fluid flow. The conical tip 26 has, on each side of the aperture 29, a longitudinal reinforcing ridge 30. Further, as can be seen in Figure 4, the portion 31 of the conical tip 26 between the ridges 30 is concave rather than convex. The ridges 30 and the concave portion 31 provide rigidity round the aperture 29, to ensure that the needle 23 functions properly. Four support ribs 32 are formed at the junction of the barrel 22 and the needle 23, again to ensure that the needle 23 is sufficiently rigid. The ridges 30, concave portion 31 and ribs 32 all provide sufficient rigidity to enable the syringe to be made of a relatively soft plastics material such as polypropylene.

In use the piercing point 27 is used to puncture the seal on a container of sterile liquid. The plunger is then withdrawn to draw liquid into the barrel body 24 through the aperture 29 and passage 28. The liquid can be dispensed from the aperture 29 by pushing the plunger back into the barrel 22, for adding to a vaccine or other powder to reconstitute it for injection.

The syringe according to the invention has the advantage that it is inexpensive to produce, as the barrel and needle are formed by a single injection-moulding process, and the only other assembly process is the insertion of the plunger. It is also very easy to use, as the needle is ready on the barrel, and does not require assembly by the user. Furthermore, the needle, being of plastics, is safer to use than a metal needle and because the needle is not adapted to pierce skin, there is less likelihood that the syringe can be misused for injections after use for reconstitution. In order to prevent re-use, the syringe may have any known autodestruct mechanism. An autodestruct mechanism ensures that the syringe can only be used once. It will be appreciated that it is easy to adapt an existing syringe design to be a reconstitution syringe simply by adapting the mould to replace the distal projection 7 by the needle 23.

In a modification, not shown, further reinforcing ridges may be provided, on the conical end and/or on the cylindrical portion.

Claims

1. A reconstitution syringe comprising a barrel (24) of plastics material characterised in that said barrel (22) has an integrally- formed hollow needle (23) , the needle (23) having a piercing point (27) , a passage (28) connecting the barrel (22) to an aperture (29) allowing fluid to flow into and out of the needle (23), and reinforcement means (30, 31 , 32) at least in the region of the aperture (29) .

2. A syringe as claimed in Claim 1 , in which the needle (23) has a closed conical end (26) formed with the piercing point (27) .

3. A syringe as claimed in Claim 2, in which the aperture (29) is formed in the conical part (26) .

4. A syringe as claimed in any preceding claim, in which the aperture (29) is circular.

5. A syringe as claimed in any preceding claim, in which the aperture (29) is elliptical.

6. A syringe as claimed in any preceding claim, in which the angle between the aperture (29) and the passage (28) is less than 90°.

7. A syringe as claimed in any preceding claim, in which the reinforcement means includes a longitudinal ridge (30) on each side of the aperture (29) .

8. A syringe as claimed in Claim 7, in which further longitudinal ridges are provided to ensure the needle (23) has the required rigidity.

9. A syringe as claimed in any preceding claim, in which the part of the needle (23) which contains the aperture (29) is concave (31) .

10. A syringe as claimed in any preceding claim, in which supporting ribs (32) are provided at the junction of the barrel (24) and the needle (23) .

11. A syringe as claimed in any preceding claim, in which the syringe (21) is of the autodestruct type.

12. A syringe as claimed in any preceding claim, in which the syringe (21) is moulded of polypropylene.