Pre-Filled Disposable Injection Device

Abstract

The present invention relates to a pre-filled disposable injection device and a needle cannula in combination. The prefilled disposable injection device (1) is made from a housing (2) containing a non-exchangeable cartridge (10) for storing a liquid drug sufficient for a number of injections. The proximal end of the pre-filled injection device (1) carries the dose setting button (3) and the distal end carries the needle cannula (20) having a lumen (21) through which the settable dose is expelled. The distal end (23) of the needle cannula (20) is covered by a telescopic needle covering shield (30) which shield (30) can operate between a first position covering the tip (24) of the needle cannula (20) and a second retracted position allowing an injection to be performed. The shield (30) carries a cleaner (50) which cleans at least the tip (24) of the needle cannula (20) between successive injections such that the prefilled injection device can be used without changing the needle cannula (20) during its life cycle.

Claims

1. A pre-filled disposable injection device having a needle cannula permanently mounted thereon, comprising: a housing containing a non-exchangeable cartridge for storing a liquid drug sufficient for a number of injections, and which cartridge is permanently embedded in the injection device, a settable dose setting mechanism having a dose setting button whereby a user can set a size of a dose to be injected, the needle cannula, which is maintained attached to the injection device between injections and permanently mounted to the housing of the injection device and follows a life cycle of the pre-filled injection device, comprising a front part having a tip for penetrating skin of the user, a back part for penetrating into the cartridge, and a lumen usable for passage of the liquid drug in the non-exchangeable cartridge through an initial injection followed by a successive number of injections sufficient to deplete the liquid drug in the cartridge, a telescopic needle covering shield distally carrying a cleaner comprising a hollow chamber containing a liquid cleaning solvent, and which shield can operate between a first position and a second position; the first position being a position in which the telescopic shield is in an extended position covering the tip of the front part of the needle cannula, the second position being a position in which the shield is retracted such that at least the tip of the front part of the needle cannula is exposed to perform an injection, and wherein at least the lumen of the needle cannula is preserved in a sterile condition prior to the initial injection and wherein a resilient structure automatically returns the shield to the first position following both the initial injection and any of the successive injections, and in which the first position at least the tip of the front part of the needle cannula is contained within the cleaner to thereby prevent clogging of the lumen of the needle cannula, wherein the shield allows for a plurality of doses where the shield operates between the first position and the second position a plurality of times.

2. A pre-filled disposable injection device according to claim 1, which further comprises a valve which is configured to prevent flow passage through the lumen of the needle cannula when the needle shield is in its first position.

3. A pre-filled disposable injection device according to claim 1, wherein the back part of the needle cannula is movable relatively to the cartridge between a non-flow position in which the back part of the needle cannula is disconnected from the cartridge such that the liquid drug flow through the lumen is interrupted, and a flow position in which the back part of the needle cannula is connected to the cartridge such that the liquid drug can flow freely through the lumen, wherein the back part of the needle cannula is in the non-flow position when the shield is in its first position and the back part of the needle cannula is in the flow position when the shield is in its second position.

4. A pre-filled disposable injection device according to claim 1, wherein the back part of the needle cannula is movable relatively to the cartridge between a non-flow position in which the back part of the needle cannula is disconnected from the cartridge such that the liquid drug flow through the lumen is interrupted, and a flow position in which the back part of the needle cannula is connected to the cartridge such that the liquid drug can flow through the lumen, wherein the back part of the needle cannula is moved from the non-flow position to the flow position when the shield is moved from its first position to its second position during the initial injection and wherein the back part remains in the flow position when the shield moves back to its first position.

5. A pre-filled disposable injection device according to claim 3, wherein the needle cannula is secured to an axial movable hub.

6. A pre-filled disposable injection device according to claim 1, wherein the shield is locked by a locking mechanism preventing the shield from moving from the first position to the second retracted position unless a dose has been dialled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0088] The invention will be explained more fully below in connection with a preferred embodiment and with reference to the drawings in which:

[0089] FIGS. 1a-b show a cross sectional view of the pre-filled injection device.

[0090] FIGS. 2-3 show different examples of sterile packages.

[0091] FIGS. 4-5 show different examples of sterile caps or covers.

[0092] FIGS. 6-8 show a cross sectional view of the distal end of the pre-filled injection device.

[0093] FIGS. 9-10 show a valve mechanism.

[0094] FIGS. 11-13 show an embodiment having an axial movable needle cannula.

[0095] FIGS. 14-16 show an embodiment having a connectable needle cannula.

[0096] FIGS. 17-18 show a locking mechanism for the needle shield.

[0097] FIGS. 19-20 show a mechanism for setting an individual injection depth.

[0098] The figures are schematic and simplified for clarity, and they just show details, which are essential to the understanding of the invention, while other details are left out. Throughout, the same reference numerals are used for identical or corresponding parts.

DETAILED DESCRIPTION OF EMBODIMENT

[0099] When in the following terms as “upper” and “lower”, “right” and “left”, “horizontal” and “vertical”, “clockwise” and “counter clockwise” or similar relative expressions are used, these only refer to the appended figures and not to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as there relative dimensions are intended to serve illustrative purposes only.

[0100] In that context it may be convenient to define that the term “distal end” in the appended figures is meant to refer to the end of the injection device which usually carries the needle cannula whereas the term “proximal end” is meant to refer to the opposite end pointing away from the injection needle and carrying the injection button 3 as depicted in FIGS. 1a-b.

[0101] FIGS. 1a-b discloses a pre-filled injection device 1 wherein a cartridge 10 is permanently embedded in the housing 2. At the proximal end a dose setting button 3 for setting a random dose size is provided. The distal end carries a needle cannula 20 which in the disclosed embodiment is permanently secured to the housing 3. The distal end of the housing 2 together with the needle cannula 20 and the needle shield 30 is preferably covered by a cap 4, an example of which is depicted in FIG. 8.

[0102] The needle cannula 20 has a proximal end 22 which penetrates through the septum 11 of the cartridge 10. Whenever the plunger 12 is moved in the distal direction inside the cartridge 10, an amount of the liquid drug contained in the cartridge 10 is pressed through the lumen 21 (See e.g. FIGS. 6-7) of the needle cannula 20 thereby to be ejected from the distal end 23 of the needle cannula 20.

[0103] The distal end 23 of the needle cannula 20 and its pointed tip 24 is physically protected by a telescopic movable needle shield 30. This shield 30 is urged in the distal direction by a spring 31 encompassed between the housing 2 and the shield 30. The spring 31 could alternatively be moulded as a part of the housing 2 or as a part of the shield 30.

[0104] The shield 30 is provided with a holding portion 33 in which a cleaner 50 can be mounted. The cleaner 50 can, as explained later, be any kind of cleaner 50 suitable of cleaning the pointed tip 24 of the needle cannula 20 before performing an injection.

[0105] By rotating the dose setting button 3 a user can set a random dose size to be ejected from the injection device 1 as it commonly known. The mechanism ejecting the set dose can be any known mechanism, either manual or automatic. Once the user presses the distal end of the injection device 1 against the skin, the shield 30 is telescopically moved in the proximal direction against the bias of the spring 31 (indicated by the arrow “A” in FIG. 7)

[0106] The pre-filled injection device 1 with the cleaner 50 mounted in the holding portion 33 and its needle cannula 20 is delivered to the user ready-to-use in a sterile confinement.

[0107] FIG. 2 discloses an embodiment in which the injection device 1 with the needle cannula 20 is delivered packed in a sterile bag 40.

[0108] FIG. 3 discloses an embodiment in which the injection device 1 with the needle cannula 20 is delivered packed in a sterile two-part container 41, 42 secured together by a peelable ribbon 43.

[0109] FIG. 4 discloses an embodiment in which the needle cannula 20 is covered by a cap 44 which is connected to the injection device 1 via a sealing 45 such that the interior of the cap 44 can be kept sterile.

[0110] FIG. 5 discloses an embodiment in which the distal end 23 of the needle cannula 20 is covered by an inner cap 46 which is sealed to the injection device 1 to maintain the interior of the inner cap 46 sterile.

[0111] When the user starts using the pre-filled injection device he or she breaks the sterile barrier i.e. when the first initial injection is performed the lumen of the needle cannula 20 will be sterile.

[0112] FIG. 6 and FIG. 7 discloses an embodiment in which the telescopic movable needle shield 30 carries the cleaner 50 which has a chamber 51 holding a suitable amount of a liquid cleaning solvent. The proximal part 52 of the cleaner 50 and the distal part 53 of the cleaner 50 are formed from a material which the needle cannula 20 can easily penetrate. The two parts 52, 53 can be separate parts 52, 53 connected together in any known manner. The material used is preferably a rubber composition as known from the septum part of any known drug container. The proximal part 52 and the distal part 53 is preferably self-sealing i.e they close by the inherent resiliency as the needle cannula 20 is removed from the penetration point. Between injections as depicted in FIG. 6, when the spring 31 urges the shield 30 in the distal direction, the pointed tip 24 of the needle cannula 20 is moved to a position located inside the chamber 51 and is thus cleaned.

[0113] When the user performs an injection as disclosed in FIG. 7, the shield 30 is moved in the proximal direction (arrow “A”) against the bias of the spring 31, and the pointed tip 24 of the needle cannula 20 penetrates through the distal part 53 of the cleaner 50. When doing so, the front part 23 of the needle cannula 20 is physically swept by the distal part 53.

[0114] When not in use, the distal end of the injection device 1 can be covered by a cap 4 as depicted in FIG. 8. In FIG. 8, the cap 4 is depicted in the process of being mounted as indicated by the arrow “B”. As disclosed in FIG. 8, the cap 4 can distally be provided with a sponge 56 or the like treated with an anti-bacterial substance such that when the sponge 56 is pressed against the distal end or part 53 of the cleaner 50, the outer surface of its distal end 53 is cleaned.

[0115] In an alternative embodiment, the chamber 51 can be solid such that the cleaner 50 is instead one solid plug 55 as depicted in the FIGS. 11 to 13. The cleaning is thus restricted to the physical engagement between the exterior of the needle cannula 20 and the material of the solid plug 55, which material can contain antibacterial particles.

[0116] FIG. 9 and FIG. 10 discloses an embodiment in which the proximal end 22 of the needle cannula 20 and the distal end 23 are connected by a flexible tube 25. Between injections a valve mechanism 60 comprising a plurality of squeeze arms 61 squeezes the flexible tube 25 such that flow passage through the needle cannula 20 is prevented.

[0117] During injection, a plurality of arms 32 provided proximally on the needle shield 30 releases the valve mechanism 60 such that the liquid drug can flow through the lumen 21 of the needle cannula 20 as depicted in FIG. 10.

[0118] FIGS. 11, 12 and 13 discloses an alternative way of prevented flow passage through the lumen 21 of the needle cannula 20. The needle cannula 20 is secured in a movable hub 65 which is able to move axially between an extended position (FIG. 11) and a retracted position (FIG. 13). A hub spring 66 is provided between the housing 2 and the movable hub 65 urging the movable hub 65 into its extended position. In this extended position, the proximal part 22 of the needle cannula 20 is located outside, and distally in front of, the septum 11 of the cartridge 10.

[0119] During injection, the user presses (arrow “C”) the shield 30 against his or hers skin whereby the distal end 23 of the needle cannula 20 projects beyond the shield 30 as depicted in FIG. 12. This happens against the bias of the spring 31. A further pressure as depicted in FIG. 14 moves the movable hub 65 in the proximal direction against the bias of the hub spring 66 whereby the proximal end 22 of the needle cannula 20 penetrates through the septum 11 thereby creating liquid communication between the user and the interior of the drug cartridge 10 such that the liquid drug contained inside the cartridge 10 can flow into the user in accordance with the set dose.

[0120] The distribution of forces between the spring 31 and the hub spring 66 determines which of the shield 30 or the hub 65 that moves first once the pressure (arrow C) is applied.

[0121] FIGS. 14-16 discloses a similar embodiment. FIG. 14 depictures the shield 30 in its default position prior to injection, in which position the proximal end 22 is protected by a sterility barrier 26, which can e.g. be a latex bag sealed to the movable hub 65. When a user applies a pressure (arrow “D” in FIG. 15) by pushing the shield 30 against the skin an intermediate piece 67 which couples the shield 30 to the movable hub 65 is moved in the proximal direction. This proximal movement is transferred to the movable hub 65 and thus to the needle cannula 20. Ultimately, the proximal end 22 of the needle cannula 20 penetrates through its sterility barrier 26 and through the septum 11 as depicted in FIG. 15. In this position the intermediate part 67 and/or the movable hub 65 locks such that the proximal end 22 remains inserted through the septum 11 as depicted in FIG. 16. Once the pressure (arrow D) is removed (FIG. 16) the spring 31 urges the shield 30 back into its extended position whereas the intermediate piece 67 and the movable hub 65 remain in their locked position.

[0122] The intermediate piece 67 is preferably provided with stops 68 cooperating with similar stops 34 provided on the shield 30 to stop the shield 30 in its extended position.

[0123] FIG. 17 and FIG. 18 discloses an embodiment in which the shield 30 is prevented from moving in the proximal direction by a locking shield 70. This locking shield 70 cooperates with the dose setting button 3 in the following manor. When no dose has been set, the locking shield 70 prevents the proximal movement of the shield 30. When the user sets a dose i.e. the non-shown scale drum is rotated away from its zero position, the locking shield 70 moves either rotational or proximal to a position allowing the shield 30 to move proximally.

[0124] After injection, the scale drum automatically returns to its zero position where after the user removes the needle cannula 20 from the skin. When no force is applied to the distal end of the shield 30 it returns to its initial position covering the pointed tip 24 of the needle cannula 20 where after the locking shield 70 returns to its blocking position preventing the shield 30 from moving proximally until next time the user dials a new dose to be injected.

[0125] FIG. 19 and FIG. 20 discloses the distal end of the housing 2 of an embodiment of the injection device 1. The distal part of the housing 2 is provided with a plurality of longitudinal ridges 5. These ridges 5 guides flexible arms 34 provided on the shield 30 as depicted in FIG. 20 such that the needle shield 30 can slide axially in relation to the housing 2.

[0126] Each ridge 5 has a specific axial length which is determined by the position of a plurality of axial stops 6. These stops 6 each prevents further axial movement of the needle shield 30. If the user rotates the needle shield 30 when in the stopping position, the needle shield 30 can be parked in its retracted position due to the gap 7 provided rotational aligned with each stop 6.

[0127] Prior to each injection, the user can rotate the shield 30 relatively to the housing 2 thereby determining the axial length the shield 30 can move which in turn is decisive for the depth into the subcutaneous layer of the user the distal part 23 of the needle cannula 20 penetrates during injection. The axial length available in each position could e.g. be printed on the shield 30.

[0128] Some preferred embodiments have been shown in the foregoing, but it should be stressed that the invention is not limited to these, but may be embodied in other ways within the subject matter defined in the following claims.