IMPROVED AUTOINJECTOR SUPPORTING THE SYRINGE AT THE FRONT

• US 20100152655A1
• Filed: 01/17/2007
• Published: 06/17/2010
• Est. Priority Date: 01/23/2006
• Status: Active Grant

• Current Assignee: Shl Medical AG
• Original Assignee: The Medical House PLC (Recipharm AB)
• Inventors: Stamp, Kevin
• Granted Patent: US 8,647,299 B2
• Time in Patent Office: Days
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/244 by flexible clip
• CPC Class Codes: A61M 2005/3118 via the distal end of a syringe, i.e. syringe end for mounting a needle cannula
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/3134 characterised by constructional features of the distal end, i.e. end closest to the tip of the needle cannula
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001
• CPC Class Codes: A61M 5/3204 Needle cap remover, i.e. devices to dislodge protection cover from needle or needle hub, e.g. deshielding devices
• CPC Class Codes: A61M 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An autoinjector comprising a housing in which can be mounted a syringe comprising a barrel for holding a volume of medicament, a needle at one end of the barrel in fluid communication with the medicament and a plunger axially-moveable in the barrel to a forwardmost position, the autoinjector further comprising a syringe support means for supporting the barrel at an axial location at or forward of the forwardmost position of the plunger and having a reaction surface for the syringe, whereby in use said reaction surface (109) provides an axial compressive force on said barrel when a forward axial force is applied to the plunger.

Claims

1. An autoinjector comprising a housing in which can be mounted a syringe comprising

a barrel for holding a volume of medicament,

a needle at one end of the barrel in fluid communication with the medicament,

a plunger axially-moveable in the barrel to a forwardmost position, the autoinjector further comprising

a needle sheath which seals the forwardmost end of the needle to maintain sterility of the medicament within the barrel whereby, in use, the needle sheath must be removed from the needle immediately prior to actuating the autoinjector;

and

a syringe support means for supporting the barrel at an axial location at or forward of the forwardmost position of the plunger and having a reaction surface for the syringe, whereby in use said reaction surface provides an axial compressive force on said barrel when a forward axial force is applied to the plunger.

2. The autoinjector of claim 1 wherein said needle sheath substantially covers said needle to protect the needle from mechanical damage.

3. The autoinjector of claim 1 wherein said needle sheath entirely covers said needle and seals against the syringe to maintain sterility of the external surface of the needle.

4. The autoinjector of claim 1 wherein said needle sheath comprises a solid elastomeric material into which the needle is spiked.

5. The autoinjector of claim 1 wherein said needle sheath is capable of being removed from the needle in an axially-forward direction immediately prior to actuating the autoinjector.

6. The autoinjector of claim 1 wherein said needle sheath is contained within a needle cover.

7. The autoinjector of claim 1 wherein said autoinjector is a single-use autoinjector.

8. The autoinjector of claim 1 further comprising an energy source for moving said plunger axially in the barrel to deliver an injection in less than 30 seconds.

9. The autoinjector of claim 1 wherein the syringe is axially moveable in said housing and is biased so that the needle is normally wholly inside said housing, wherein before injection the syringe is movable axially so as to move at least a part of said needle out of the housing and wherein after injection, the syringe is able to retract in order to retract said part of said needle into the housing.

10. The autoinjector of claim 1 wherein, in use, said reaction surface provides an axial compressive force to a front shoulder of the syringe barrel.

11. The autoinjector of claim 1 wherein, in use, said reaction surface provides an axial compressive force to a front cone of the syringe barrel.

12. The autoinjector of claim 1 wherein said syringe support means includes one or more inwardly-directed protrusions forming said reaction surface.

13. The autoinjector of claim 12 wherein said inwardly-directed protrusions are on the end of one or more radially-flexible fingers.

14. The autoinjector of claim 13 wherein said inwardly-directed protrusions comprise an inwardly-directed enlarged head on each radially-flexible finger.

15. The autoinjector of claim 13 further comprising a spring retainer, preferably made from steel, for urging each radially-flexible finger inwardly.

16. The autoinjector of claim 12 wherein the internal diameter between said inwardly-directed protrusions is smaller than the exterior diameter of the syringe barrel.

17. The autoinjector of claim 16 wherein, when the autoinjector is fully assembled ready for use, said inwardly-directed protrusions are axially located between a needle cover and the front shoulder of the syringe barrel.

18. The autoinjector of claim 1 wherein said syringe support means is generally cylindrical and of a diameter less than a diameter of a finger flange of the syringe barrel so that the syringe support means is suitably sized to closely surround the barrel of the syringe, in use.

19. The autoinjector of claim 1 wherein said syringe support means is capable of supporting said syringe barrel at a specific axial location with respect thereto.

20. The autoinjector of claim 1 wherein said syringe support means includes one or more viewing windows, to permit a user to view the barrel of a syringe supported therein.

21. The autoinjector of claim 20 wherein said one or more viewing windows comprise one or more apertures in the syringe support means.

22. The autoinjector of claim 20 wherein said one or more viewing windows comprise a transparent or partially transparent part of the syringe support means.

23. The autoinjector of claim 1 wherein said syringe support means further comprises one or more alignment tags at the front end thereof.

24. The autoinjector of claim 23 further comprising a front housing having a bore therethrough, the interior surface of the bore being provided with one or more longitudinal slots, positioned so that said alignment tags can locate therein, when said front housing and syringe support means are assembled together.

25. The autoinjector of claim 24 wherein each longitudinal slot comprises a rear section having a forwardly-increasing depth and a forward section having substantially constant depth.

26. The autoinjector of claim 25 wherein a boundary between the rear and forward sections is defined by a step.

27. The autoinjector of claim 26 further comprising an end cap having internal protrusions therein which protrude into the longitudinal slots in the bore of the front housing, when said end cap and said front housing are assembled together, so that a space is defined between said internal protrusions in the end cap and said step in the front housing.

28. The autoinjector of claim 27 wherein the alignment tags of the syringe support means locate into said defined space to determine an axial location of the syringe support means with respect to said front housing.

29. The autoinjector of claim 24 wherein said syringe support means includes a radially-extending flange, of greater diameter than an interior diameter of said front housing.

30. The autoinjector of claim 27 wherein, when assembled together, said end cap, front housing and syringe support substantially prevent damage to or movement of a needle cover and/or said needle sheath on the needle of a syringe mounted in the device.

31. The autoinjector of claim 18 wherein the finger flange of the syringe barrel does not contact the syringe support means during delivery of the medicament.

32. The autoinjector of claim 13, wherein said radially-flexible fingers can flex sufficiently outwardly to allow a needle cover, said needle sheath or the like of larger diameter than the internal diameter between said radially-flexible fingers to pass thereby during assembly of a syringe into said autoinjector.

33. The autoinjector of claim 28 wherein said radially-flexible fingers can flex sufficiently outwardly to allow a needle cover, said needle sheath or the like of larger diameter than the internal diameter between said radially-flexible fingers to pass thereby during assembly of a syringe into said autoinjector, and wherein said axial location of the syringe support means with respect to the front housing is such that said radially-flexible fingers are not confined within said front housing and are free to flex radially, when the front housing and syringe support means are assembled together and before assembly of a rear part-assembly of the autoinjector thereto.

34. The autoinjector of claim 32 wherein, when the device is fully assembled ready for use, said inwardly-directed protrusions closely abut the needle cover and/or said needle sheath to reduce the risk of said needle sheath becoming loose or detached from the needle, potentially compromising the sterility of the needle.

35. The autoinjector of claim 1 wherein the housing is an outer housing and at least part of the needle is axially moveable in and out of said outer housing but is biased to be normally wholly inside said housing, the autoinjector further comprising:

an inner housing intermediate the outer housing and the barrel and plunger; and

an energy source in communication with said inner housing,

wherein the inner housing is moveable by the energy source between three positions, namely

a first position in which the inner housing is in communication with the barrel such that, in use, the plunger and barrel are movable axially so as to move at least part of said needle out of the outer housing;

a second position in which the inner housing is in communication with the plunger but not the barrel such that, in use, said plunger is movable axially into said barrel so as to expel medicament through the needle; and

a third position in which the inner housing is in communication with neither the plunger nor the barrel such that, in use, the plunger and barrel are able to retract in order to retract the needle into the outer housing.

36. The autoinjector of claim 35 wherein said inner housing includes one or more flexible tags, biased radially inwardly by communication with said outer housing.

37. The autoinjector of claim 36 wherein one or more of said tags are situated at a rear end of the inner housing and are biased radially inwardly into communication with the plunger.

38. The autoinjector of claim 37 wherein each rear tag is moveable out of communication with the plunger when aligned with a corresponding recess in the outer housing.

39. The autoinjector of claim 36 wherein one or more of said tags are situated at a forward end of the inner housing and are biased radially inwardly into communication with the barrel.

40. The autoinjector of claim 39 wherein each forward tag is moveable out of communication with the barrel when aligned with a corresponding recess in the outer housing.

41. The autoinjector of claim 1, in which is mounted a syringe comprising

a barrel for holding a volume of medicament,

a needle at one end of the barrel in fluid communication with said medicament and

a plunger axially-moveable in the barrel to a forwardmost position.

42. (canceled)

43. A method of assembling an autoinjector comprising the steps of:

providing a first part-assembly comprising a front housing and a closely fitting end cap;

providing a second part-assembly comprising a rear part of the autoinjector;

providing a syringe comprising a barrel for holding a volume of medicament, a needle at one end of the barrel and a plunger axially-moveable in the barrel to a forwardmost position;

providing a syringe support means having a reaction surface for the syringe;

inserting the syringe axially into the rear end of the syringe support means until said syringe support means supports the syringe;

inserting the front end of said syringe and syringe support means into said first part-assembly;

assembling said first part-assembly and second part-assembly together so that said syringe support means supports the syringe at an axial location at or forward of the forwardmost position of the plunger, whereby in use said reaction surface provides an axial compressive force on said barrel when a forward axial force is applied to the plunger.

44. A method of assembling an autoinjector comprising the steps of:

providing a first part-assembly comprising a syringe support means, a front housing and a closely fitting end cap;

providing a second part-assembly comprising a rear part of the autoinjector;

providing a syringe comprising a barrel for holding a volume of medicament, a needle at one end of the barrel and a plunger axially-moveable in the barrel to a forwardmost position;

inserting the syringe axially into the rear end of the first part-assembly until said syringe support means supports the syringe;

assembling said first part-assembly and second part-assembly together so that said syringe support means supports the syringe at an axial location at or forward of the forwardmost position of the plunger, whereby in use said reaction surface provides an axial compressive force on said barrel when a forward axial force is applied to the plunger.

45. (canceled)