HK1179192B - Syringe barrel adapter and needle assembly - Google Patents

Description

Syringe barrel adapter and needle assembly

Technical Field

The present invention relates to syringes and more particularly to an adapter and/or needle assembly mounted to a retractable syringe barrel and/or a retractable syringe containing a retractable syringe barrel.

Background

Sharing insufficiently sterile syringes between consecutive users is a major route to the transmission of Human Immunodeficiency Virus (HIV) and hepatitis, and further aggravates the condition of victims, greatly burdening society with the medical attention that these victims support and provide.

In addition, health professionals sometimes come into contact with used syringes, causing accidental needle sticks with the syringe, and the risk of infection by pathogens or other contaminants.

To address this problem, retractable syringes have been developed to address the problems of syringe reuse and inadvertent sticks due to used syringes.

To develop such retractable syringes, relatively complex retractable needle assemblies have been used which can be matched to a particular shape or configuration of syringe barrel and are not adapted to fit other shapes or configurations of syringe barrels. In particular, one problem with the use of glass syringe barrels is that many glass barrels do not have the desired shape or configuration due to the small supply and therefore cannot be mounted on a retractable needle assembly.

Disclosure of Invention

It is an object of the present invention to provide an adapter which facilitates mounting of a needle assembly to a retractable syringe. It is a preferred object of the present invention to provide an adapter which avoids the need to use a specially shaped or configured cartridge for mounting to a needle assembly. It is another preferred object of the present invention to provide a relatively simplified needle assembly that includes fewer components, thereby providing a user-friendly and safe retractable syringe while maintaining a minimum manufacturing cost of the retractable syringe and/or facilitating mass distribution of the retractable syringe. Other preferred objects of the present invention are to provide for efficient delivery of liquid components, thereby minimizing waste of liquid components, and/or one or more locking systems to prevent or at least reduce syringe reuse and/or needle stick injuries.

In a first aspect, the present invention provides an adapter for mounting to a syringe barrel, the adapter comprising a body containing a needle assembly and a barrel-engaging portion.

The adapter may suitably be capable of being joined or mounted or engaged to a needle assembly of the retractable syringe.

Preferably, the adapter further comprises a needle hole. When the adapter is properly coupled with the needle assembly, the cannula of the needle assembly may be received or contained by or through the needle aperture of the adapter.

In a second aspect, the present invention provides a needle assembly mountable to a syringe barrel adapter, the needle assembly comprising a needle body, a cannula and a needle seal, wherein the needle body and the needle seal are releasably engaged.

The needle assembly may suitably be capable of being joined or mounted or engaged to a retractable syringe barrel adapter comprising a body containing a needle portion and a barrel engaging portion.

Preferably, in use, the needle seal is compressible.

Preferably, in use, the needle seal is substantially stationary.

In a particularly preferred embodiment, a needle seal is engageable with the needle portion of the adapter.

Preferably, the needle body comprises one or more fluid recovery channels. In one form, the fluid recovery channel is two opposing channels that direct fluid into the cannula.

In a third aspect, the present invention provides a syringe barrel containing an adapter according to the first aspect and a needle assembly according to the second aspect.

In a fourth aspect, the present invention provides a syringe comprising an adapter according to the first aspect, a needle assembly according to the second aspect or a syringe barrel and plunger according to the third aspect.

Preferably, the plunger comprises a plunger outer and a plunger member.

Preferably, the plunger further comprises a biasing member.

Suitably, retraction of the retractable needle is facilitated by the biasing member.

Non-limiting examples of biasing members include springs, elastic devices, or others for storing the released energy. The biasing member is preferably a spring.

Preferably, the plunger member and plunger outer cooperate to releasably maintain said biasing member in an initially energized state.

In one embodiment, the plunger further comprises a retractable needle-engaging member.

Preferably, the plunger further comprises a plunger seal.

In one embodiment, the plunger seal is mounted to the plunger member.

In a preferred embodiment, the plunger seal comprises said retractable needle-engaging member.

Preferably, the needle engagement member is engageable with the needle body to facilitate retraction of the needle.

The plunger may further comprise a control member to assist in controlling the rate of retraction. Preferably, the control rod is releasably connected to the plunger member. One particular form is where the control rod is releasably connected to the plunger member.

Preferably, the control member is releasably coupled to the outer member to maintain the biasing means in an initially energized state. More preferably, the cartridge further comprises a collar having one or more disengagable members to facilitate disengagement of the control member from the plunger outer member.

It should be understood that the present invention contemplates embodiments of the plunger. Preferably, according to these embodiments, the plunger comprises one or more elements that assist in locking the plunger to the syringe barrel after the syringe has been injected with the liquid composition and/or after needle retraction has been completed to prevent or hinder re-use of the syringe.

In one embodiment, the plunger includes a plunger member, a plunger outer and a first locking member that prevents or hinders further movement of the plunger member relative to the plunger outer and/or the barrel after needle retraction. Suitably, the locking member is mounted to the plunger outer. In a particular embodiment, the locking member is a lock spring.

According to this embodiment, preferably, a further lock is further provided formed between the barrel element, or collar mounted to the syringe barrel, and the plunger outer after the syringe has been injected with the liquid composition. Preferably, the plunger outer comprises a second locking member capable of engaging the barrel. The second locking member is adapted to engage the barrel to prevent or hinder further movement of the plunger outer relative to the barrel upon completion of injection of the liquid composition.

An example of such a preferred embodiment is provided by PCT/AU2010/001677, incorporated herein by reference.

In another embodiment, one said locking system comprises respective elements of said barrel and said plunger outer. Preferably, according to this embodiment, the locking system comprises elements of said collar and said plunger outer.

In another form of this further embodiment, another said locking system comprises elements of said plunger member and said plunger outer.

Preferably, said syringe comprises both said locking systems.

An example of a locking system according to this further embodiment is described in international publication WO2009/003234, which is hereby incorporated by reference.

In a fifth aspect, the present invention provides a method of assembling the needle assembly of the second aspect, the syringe barrel of the third aspect and/or the syringe of the fourth aspect, the method comprising the step of assembling the components thereof to produce the needle assembly of the second aspect, the syringe barrel of the third aspect and/or the syringe of the fourth aspect.

In a sixth aspect, the present invention provides a method of using the syringe of the fourth aspect, comprising the step of delivering the liquid component to the body.

Preferably, the syringe of the above-mentioned aspect is a retractable syringe.

More preferably, the syringe is a pre-filled retractable syringe.

In this specification, unless otherwise indicated, "comprise" shall be taken to mean inclusion, rather than limitation, such that a specified integer or group of integers may include one or more other unspecified integers or groups of integers.

Drawings

Non-limiting embodiments of the present invention are described herein with reference to the following drawings, wherein:

FIG. 1 is a cross-sectional view of one embodiment of a retractable syringe;

FIG. 2 is a cross-sectional view of one embodiment of the adapter and needle assembly mounted to a retractable syringe barrel;

FIG. 3 is a cross-sectional view of one embodiment of an adapter;

FIG. 4 is a cross-sectional view of one embodiment of a needle seal;

FIG. 5 is a cross-sectional view of one embodiment of a needle body and cannula;

FIG. 6 is an exploded perspective view of one embodiment of a plunger;

FIG. 7 is a cross-sectional view of an embodiment of a plunger seal;

FIG. 8 is a cross-sectional view of one embodiment of the plunger of the retractable syringe immediately prior to completion of injection of the liquid composition;

FIG. 9 is a cross-sectional view of one embodiment of the needle body incorporating a plunger seal prior to needle retraction;

FIG. 10 is a cross-sectional view of one embodiment of the plunger immediately prior to retraction;

FIG. 11 is a cross-sectional view of one embodiment of the retractable syringe during retraction of the plunger and the retractable needle engaged therewith;

FIG. 12 is a cross-sectional view of the lock formed between the barrel collar and the plunger outer and the lock formed between the plunger outer and the plunger inner after retraction of the plunger;

FIG. 13 is a cross-sectional view of another embodiment of a needle seal;

FIG. 14 is a cross-sectional view of another embodiment of a needle seal and another embodiment of a needle body;

fig. 15 is a cross-sectional view of another embodiment of a needle seal and a needle body.

Detailed description of the preferred embodiments

Referring to fig. 1, one embodiment of a retractable syringe 100 includes a barrel 110 having a plunger end 114 and a needle end 115. The barrel 110 is substantially cylindrical and is preferably a glass profile. A collar 113 containing a disengagable ring 130 is located at the end of the bung 114 of the syringe barrel 110. The collar 113 may be mounted, adhered, assembled to the syringe barrel 110, or integral with the syringe barrel 110. In embodiments, the collar 113 may be glued or otherwise attached to the glass profile barrel 110. In another embodiment, the collar 113 may be integrally formed (e.g., molded) with the barrel 110 of plastic or other moldable material. The releasable ring 130 may be mounted or assembled to the barrel 110, or co-molded with the collar 113 and the barrel 110. Typically, syringe 100 is shielded by boot 121 over cannula 410 to protect cannula tip 411. At needle end 115 of barrel 110, barrel adapter 300 and needle assembly 400 including cannula 410, needle body 420 and needle seal 430 are mounted. Syringe 100 further includes plunger 200 having plunger seal 800 mounted thereto, and barrel 110 further includes inner wall 118 which, together with needle body 420, needle seal 430 and plunger seal 800, defines fluid space 120 within barrel 110. In use, as shown in fig. 1, the plunger 200 is moved axially in the direction of the liquid space 120, as indicated by the solid arrow, to facilitate delivery of the liquid component of the retractable syringe 100. In a preferred embodiment, the liquid space 120 may be prefilled with a liquid composition to be delivered by the retractable syringe 100. In this context, "prefilled" refers to the retractable syringe 100 being provided to the user with the deliverable liquid composition already filled without the user having to fill the syringe barrel 110 with the liquid composition.

Referring to fig. 2 and 3, cartridge adapter 300 includes a needle portion 310 including a peg 311 and a needle aperture 312; a needle seal engagement member 320 comprising a mounting ring 321 comprising an annular barb 322 and a shoulder 323; and a cartridge engaging portion 330 including a circumferential shoulder 331 for abutting against the rim 119 of the cartridge 110. Referring to fig. 2-5, needle assembly 400 includes cannula 410 and needle 420, with needle 420 including plunger engagement member 421, extension 422 including retention step 423, bore 424, fluid recovery channel 427A, B where fluid reverses direction when bore 424 and cannula 410 are in fluid communication, neck 425, and needle seal 430. The needle seal 430 includes a body 431, the body 431 containing a barb seat 432 and sealing ribs 433A, 433B that help seal the liquid inside the inner wall 118 of the barrel 110. The needle seal 430 also includes a needle aperture 435, the needle aperture 435 including a needle retention portion 436 having an increased diameter as compared to the aperture 435. As shown in fig. 2, barb seat 432 receives annular barb 322 of mounting ring 321 of needle seal engaging portion 320 of cartridge adapter 300 such that needle seal 430 and cartridge adapter 300 are joined. The peg 311 bears against the surface 437 of the needle body 420 and the cannula 410 extends through the needle aperture 312 so that the cannula tip 411 is free to deliver the liquid composition once the cap 121 is removed. This arrangement allows the needle seal 430 to be stationary during all stages of use of the retractable syringe 100.

With particular reference to fig. 6 and 7, plunger 200 includes plunger member 210, plunger member 210 including shaft 211, annular projection 212, and seal engaging member 216, seal engaging member 216 being, in this embodiment, threaded projection 217 that engages complementary recess 820 on plunger seal 800. In another embodiment, the seal engaging member 216 may be in the form of a snap-lock projection that engages a complementary recess of the plunger seal 800. With particular reference to FIG. 7, the plunger seal 800 is a separate structure and includes a sealing body 840 and sealing ribs 850A, 850B, 850C that create a liquid seal between the plunger 200 and the inner wall 118 of the barrel 110. The recess 820 of the plunger seal 800 engages with the complementary seal engaging member 216 of the plunger member 210. In this embodiment, recess 820 includes internal threads 821 that engage with external threaded protrusion 217 of the plunger member. Plunger seal 800 further includes a needle engaging member in the form of a recess 810 that includes a flange 811 that receives plunger engaging member 421 of needle body 420.

With particular reference to fig. 6, plunger member 210 further includes a locking slot 219, the function of which will be described in detail below.

Plunger 200 further comprises plunger outer 220, plunger outer 220 having an elongated body 221 with a base 225 and a head 222, head 222 being mounted with a cap 223. The first locking member comprises a lock spring 224, the lock spring 224 being mounted through the head 222 and the cap 223 through a slit 226, thereby facilitating assembly of the plunger 200. Typically, the lock spring 224 is an "R-shaped" clamp of stainless steel construction. Lock spring 224 and lock groove 219 cooperate to lock plunger member 210 and plunger outer 220 together after retraction, as will be described in detail with particular reference to fig. 10. The lock spring 224 may provide up to 100 newtons of "locking" resistance, at the same level as the resistance desired for the syringe 100.

The elongate body 221 includes a second locking member including a locking finger 227 having an abutment 228. This can be seen in fig. 8. The engagement of locking fingers 227 with releasable ring 130 of collar 113 will be described in detail below with particular reference to fig. 10.

Releasably, releasably and releasably engaged with plunger member 210 is a control rod 230, control rod 230 including a button 231, an arm 232, and a shaft 233, as shown in fig. 6. Plunger 200 further includes a compression spring 270, compression spring 270 being mounted between plunger member 210 and plunger outer 220, and maintaining an initially compressed state between annular protrusion 212 of plunger member 210 and base 225 of plunger outer 220. The button 231 may have a roughened surface to enhance the user's feel and grip.

As shown in FIG. 8, control rod 230 is releasably engaged to plunger member 210 by shaft 233, and shaft 233 is releasably coupled to plunger member 210 by frangible joint 234. The control rod 230 is also releasably engaged with the plunger outer 220 to maintain the spring 270 in an initially compressed state between the annular protrusion 212 of the plunger member 210 and the base 225 of the plunger outer 220. First, the protrusions 235 of the arms 232 abut the edge 229 of the head 222 of the plunger outer 220, thereby retaining the control rod 230 and preventing the control rod 230 from moving axially relative to the plunger outer 220. However, the arm 232 of the lever 230 is resiliently flexible and movable in the direction of the solid arrow as shown in FIG. 8, which will disengage the lever 230 from the plunger outer 220 to assist in the decompression of the spring 270, as will be described in more detail below.

The sequence whereby retractable needle body 420 and cannula 410 of needle assembly 400 are disengaged from needle seal 430 to facilitate retraction of retractable needle body 420 and cannula 410 is described below.

Typically, a syringe 100 is provided that has been prefilled with a liquid composition for delivery. Thus, plunger 200 is provided in an initial position ready for decompression to effect delivery of the liquid component by syringe 100. During delivery of the liquid composition, the plunger 200 is moved axially through the barrel 110 in the direction of the solid arrow, as shown in fig. 9, until the recess 810 of the plunger seal 800 engages the plunger engagement member 421 of the retractable needle 420, causing the needle 420 and the plunger member 210 to engage. The plunger 200 continues to move axially so that the seal 800 continues to bear against the needle seal 430. Needle seal 430 cannot move axially relative to barrel adapter 300 so that body 431 of needle seal 430 is compressed sufficiently to cause arms 232 of control rod 230 to contact releasable ring 130 of collar 113 to disengage projections 235 of arms 232 from edge 229 of head 222 of plunger outer 220 to disengage control rod 230 from blocking outer 220, facilitating decompression of spring 270 to disengage (pull) retention steps 423 of needle body 420 out of needle retention portion 436 of needle seal 430, allowing retractable needle body 420 and cannula 410 of needle assembly 400 to retract into barrel 110 of syringe 100. A fluid recovery passage 427A, B in the needle body 420 helps direct the remaining fluid into the bore 424 and the cannula 410. This minimizes "dead space" and thus improves the efficiency of delivery of the liquid composition by syringe 100.

Referring to fig. 10, at the end of the injection of the liquid composition, abutments 228 of locking fingers 227 of plunger outer 220 engage with lower portion 131 of disengagable ring 130, thereby preventing plunger outer 220 from moving out of barrel 110. To retract retractable needle body 420 and cannula 410 engaged with plunger member 210, compression spring 270 must decompress, which is accomplished with the aid of plunger member 210 disengaging from plunger outer 220. Referring again to fig. 10, the arm 232 of the lever 230 bears against the releasable ring 130 of the collar 113 at the plunger end 114 of the barrel 110. The disengageable ring 130 forces the arms 232 to move radially inward in the direction of the solid horizontal arrow and disengage from the edge 229 of the head 222 of the plunger outer 220, as shown in fig. 10. This disengagement causes compression spring 270 to decompress and push on projection 212 of plunger member 210, thereby retracting plunger member 210 with control rod 230 engaged therewith, as shown in fig. 11. This disengagement may also be accompanied by an audible and/or tactile signal (e.g., "click") that prompts the user for retraction. Needle body 420 engages plunger seal 800 and is therefore retracted (along with cannula 410) into barrel 110 along with plunger member 210 in the direction of the arrow in fig. 11, thereby being completely covered by barrel 110 and contained within barrel 110. When needle retraction is "automatically" actuated by decompression of the spring 270, the rate of retraction may be controlled by the user by releasing pressure (e.g., by pressing) on the button 231 of the lever 230.

Referring to fig. 12, at the end of plunger member 210 retraction, further movement of plunger member 210 toward plunger outer 220 and/or barrel 110 is prevented by a "spring lock" of lock spring 224 around lock groove 219 of plunger member 210. Locking of plunger member 210 at the end of retraction prevents inadvertent movement of plunger member 210 from plunger outer 220, as well as inadvertent decompression of plunger member 210, both of which could expose cannula tip 411, thereby causing potential needle stick injury to the user.

At the end of retraction, control rod 230 may be broken from plunger member 210 at frangible junction 234 and manually removed from retractable syringe 100, and this process is referred to as "cleaning" waste so that virtually no external protrusion of plunger 220 from plunger outer 220 occurs in an attempt to force plunger 200 back into barrel 110 and attempt to re-engage the needle (not shown).

Referring now to fig. 13, another embodiment of a needle seal 430 is depicted. In this embodiment, the needle seal 1430 includes one or more internal circumferential ribs 1435A, B that abut the neck 1423 and retention step 1423, respectively, of the needle body 1420. The internal circumferential rib 1435A, B contacts the needle body 1420 to better resist the "needle pushing" force to maintain the needle body 1420 in the pre-retraction position. One or more internal circumferential ribs 1435 may be used to optimize the balance between the force required for the needle to dwell and retract the needle body 1420.

Referring now to fig. 14, another embodiment of a needle body 420 and an embodiment similar to the needle seal shown in fig. 13 are described. Needle seal 2430 includes one or more internal circumferential ribs 2435A, B that abut a neck 2425 and a retaining step 2423, respectively, of needle body 2420. In this embodiment, the relative depths or axial lengths of retention step 2423 and neck 2425 are reduced to a 2:1 ratio of neck 2425 to retention step 2423, which is lower than the embodiment shown in fig. 13. The embodiment of fig. 14 may better resist "needle push" forces, thereby maintaining needle body 2420 in the pre-retraction position. It should be appreciated that the relative depths or axial lengths of retention step 2423 and neck 2425 can be varied to optimize the balance between the forces required for needle retention and retraction of needle body 1420.

Another embodiment is shown in fig. 15 when the needle seal 3430 includes one or more internal circumferential ribs or rings 3435A, B that abut annular grooves 3423A, 3423B, respectively, of the needle body 3420. In this embodiment, the bond between the circumferential rib or ring 3435A, B and the annular grooves 3423A, 3423B takes an overall "hourglass" shape. It is expected that this bond will provide a strong enough bonding force to resist a 6 newton "push" force while allowing the needle body 3420 to retract from the needle seal 3430 at the appropriate time.

In view of the above, it will be appreciated that the present invention provides a relatively simple, durable and cost-effective syringe that can be automatically deactivated with little or no assistance from the user, thereby preventing or at least reducing re-use of the syringe and/or needle stick injuries from the used syringe.

More specifically, the cartridge adapter allows the needle assembly to be mounted to any straight or substantially cylindrical cartridge without the need for a specially manufactured cartridge to assemble the needle assembly.

In addition, the simplification of the needle assembly and retraction system is achieved by eliminating the need for a separate injector to facilitate needle disengagement to facilitate retraction.

The dual locking system described herein may also be referred to by virtue of locking the plunger outer to the barrel and the plunger member to the plunger outer, thereby preventing removal and/or further movement of the plunger. In particular, the snap lock may resist up to 100 newtons of force to prevent or hinder further movement of the moving plunger member after retraction. By providing a dual locking system, one or the other locking system may not fail inadvertently, or overcome damage from an improper user, without causing a complete failure of the plunger to latch.

It will also be appreciated that the fluid recovery channel of the retractable needle body provides greater efficiency for the delivery of fluid components that occurs just prior to retraction of the needle. Where the liquid component is a very expensive drug or other compound, increasing production efficiency on a large scale can result in considerable cost savings.

Throughout this specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. Various modifications and variations of the described and illustrated embodiments of the invention may be made without departing from the invention.

Each of the patent and scientific literature, computer programs and algorithms referred to in this specification are incorporated herein by reference in their entirety.

Claims (38)

1. An adapter mountable to a substantially cylindrical retractable syringe barrel, said adapter comprising a body including a needle portion and a barrel engagement portion, wherein said barrel engagement portion includes a circumferential shoulder mountable to a rim of a needle end of said substantially cylindrical barrel, said adapter being engageable with a needle seal releasably engaged with a needle body of a needle assembly of said retractable syringe.

2. The adapter of claim 1, further comprising a needle aperture through which a cannula of a needle assembly protrudes when coupled with the adapter.

3. The adapter of claim 1, further comprising one or more means for engaging a needle seal of a needle assembly.

4. The adapter of claim 3, wherein the one or more members include barbs.

5. The adapter of claim 3, wherein the one or more members engage with a barb seat of a needle seal.

6. A needle assembly mountable to the retractable syringe barrel adapter of claim 1, wherein the needle assembly comprises a needle body, a cannula and a needle seal, wherein the needle body and needle seal are releasably engaged.

7. The needle assembly as defined in claim 6, wherein the needle seal includes one or more members for engaging the barrel adapter.

8. The needle assembly as defined in claim 7, wherein the one or more members include a barb seat.

9. The needle assembly as defined in claim 7, wherein the one or more members engage a barb of the needle seal.

10. The needle assembly of claim 6, wherein, when in use, the needle seal is substantially stationary during retraction of the needle body and cannula.

11. The needle assembly of claim 6, wherein the needle seal is compressible.

12. The needle assembly of claim 6, wherein the needle body comprises a plunger engagement portion.

13. The needle assembly of claim 6, which does not include an injector member.

14. The needle assembly of claim 6, which does not include a retaining member separate from the needle seal.

15. The needle assembly of claim 6, wherein the needle body comprises one or more fluid recovery channels.

16. A substantially cylindrical retractable syringe barrel comprising the adapter of claim 1 mounted thereon.

17. The substantially cylindrical retractable syringe barrel of claim 16 further comprising the needle assembly of claim 6 mounted thereto.

18. The substantially cylindrical retractable syringe barrel of claim 16 further comprising a collar mounted thereto.

19. A retractable syringe comprising (i) the adapter of any one of claims 1 to 5; (ii) the needle assembly as defined in any one of claims 6 to 15; and/or (iii) a substantially cylindrical retractable syringe barrel according to claim 16, 17 or 18.

20. The retractable syringe of claim 19, further comprising a plunger.

21. The retractable syringe of claim 20, wherein the plunger comprises a plunger member and a plunger outer.

22. The retractable syringe of claim 20, wherein the plunger further comprises a biasing member.

23. The retractable syringe of claim 22, wherein the plunger member and plunger outer cooperate to releasably retain the biasing member in an initially energized state.

24. The retractable syringe of claim 23, wherein the biasing member is an initially compressed spring.

25. The retractable syringe of claim 20, wherein the plunger further comprises a needle engagement member.

26. The retractable syringe of claim 20, wherein the plunger further comprises a plunger seal.

27. The retractable syringe of claim 26, wherein the plunger seal is mounted to the plunger member.

28. The retractable syringe of claim 26, wherein the plunger seal comprises a needle engaging member.

29. The retractable syringe of claim 20, wherein the plunger further comprises a control rod that facilitates control of a rate of needle retraction.

30. The retractable syringe of claim 29, wherein the control rod and plunger member are releasably connected.

31. The retractable syringe of claim 30, wherein said control rod and plunger member are frangibly connected.

32. The retractable syringe of claim 19, further comprising one or more locks, locking members, or locking systems.

33. The retractable syringe of claim 20, wherein the plunger comprises a plunger member, a plunger outer and a first locking system that prevents or hinders further movement of the plunger member relative to the plunger outer and/or the barrel after needle retraction.

34. The retractable syringe of claim 33, wherein the first locking system is mounted to the plunger outer.

35. The retractable syringe of claim 34, wherein the first locking system is a lock spring.

36. The retractable syringe of claim 32, comprising a lock formed between a barrel element or collar mounted to a barrel and a plunger outer after injection of a liquid composition of the syringe.

37. The retractable syringe of claim 36, wherein the plunger outer comprises a second locking member engageable with the barrel to thereby prevent or hinder further movement of the plunger outer relative to the barrel when the liquid composition has been injected.

38. The retractable syringe of claim 19, which is a pre-filled syringe.