Safety device for mounting to drug delivery device

Abstract

A safety device for mounting to a drug delivery device. The present invention relates to a safety device (10) for mounting to a drug delivery device (100) having a barrel (102) comprising a flange (107) at a proximal end thereof and an injection needle (101) at a distal end thereof, and a piston rod (110) having a piston flange (114), the safety device (10) comprising: a collar (2) having at least one locking member, the locking member is configured to lock the collar (2) relative to the piston flange (114); a sleeve (3) configured to slide on the barrel (102), the sleeve (3) having at least one locking member configured to lock the sleeve (3) relative to the barrel (102); a flexible member connecting the collar (2) and the sleeve (3) and keeping the collar (2) and the sleeve (3) axially spaced apart, the flexible member being configured to effect an elastic deformation of storing energy when the collar (2) is pushed towards the sleeve (3) and to release energy when the sleeve (3) is unlocked from the sleeve (102), the locking member of the sleeve (3) comprising at least one leg (6) extending in a cantilevered manner from the sleeve (3) towards the collar (2), the leg (6) has a leg hook member (7) configured to hook onto the barrel flange (107), the leg hook member being operable to unlock the sleeve (3) from the barrel (102) so as to release energy stored in the flexible member when the sleeve is unlocked from the barrel.

Description

Technical Field

[0001] The present invention relates to a safety device for attachment to a drug delivery device, such as a pre-filled or pre-fillable syringe, so as to protect a user from a needle stick injury after injection of a medical product. The present invention also relates to a drug delivery device incorporating such a safety device. Background Art

[0002] In the present application, the distal end of a component or device should be understood to refer to the end furthest from the user's hand, while the proximal end should be understood to refer to the end closest to the user's hand. Similarly, in the present application, "distal direction" should be understood to refer to the injection direction with respect to the safety device or drug delivery device of the present invention, and "proximal direction" should be understood to refer to the direction opposite to the said injection direction, that is, the direction towards the user's hand.

[0003] A drug delivery device, such as a pre-fillable or pre-filled syringe, typically includes a hollow body or barrel forming a container for a medical product. The body includes a distal end in the form of a longitudinal end, the distal end defining an axial passage through which the medical product is discharged from the container. The distal end is equipped with a needle for injecting the medical product into an injection site.

[0004] Protecting patients and users from any risk of needle stick injury is of great importance, especially during the period between the end of injection and the disposal of the drug delivery device.

[0005] In order to minimize the risk of needle stick injury, the drug delivery device can be equipped with a safety device that protects the needle after injection.

[0006] Although known safety devices are generally satisfactory, they do not always meet all the expectations of users, and they may contain many components. Therefore, their manufacturing cost may be high, and this may limit the widespread use of safety devices, which is at the expense of the safety of medical users and patients.

[0007] They also tend to contain components made of various materials, and the recycling of these components may be complex and costly. Summary of the Invention

[0008] There is a need for an improved safety solution that provides a more convenient safety device for users, which is also cost-effective and easy to manufacture.

[0009] In one aspect, the present invention relates to a safety device for attachment to a drug delivery device having a barrel and a piston rod, the barrel comprising a flange at its proximal end and an injection needle at its distal end, the piston rod having a piston flange, the safety device comprising:

[0010] a collar having at least one locking member configured to lock the collar relative to the piston flange;

[0011] a sleeve configured to slide on the barrel, the sleeve having at least one locking member configured to lock the sleeve relative to the barrel;

[0012] a flexible member connecting the collar and the sleeve and maintaining the collar and the sleeve axially spaced apart, the flexible member being configured to undergo elastic deformation storing energy when the collar is pushed towards the sleeve and to release the energy when the locking member of the sleeve is operable to unlock the sleeve from the barrel, so as to release the energy stored in the flexible member when the sleeve is unlocked from the barrel.

[0013] Various other embodiments of the present invention may include the following.

[0014] - The flexible member comprises at least one elastic blade connecting the sleeve and the collar.

[0015] - The collar comprises at least one collar hook member configured to lock onto the piston flange, the collar hook member axially protruding from the collar in a cantilever manner in the proximal direction, the hook member having an inclined ramp surface at its free end.

[0016] - The collar comprises two collar hook members spaced 180° apart.

[0017] - The collar comprises at least one finger member protruding from the collar in a cantilever manner in the distal direction, the finger member having inclined proximal and distal ramp surfaces, the ramp surfaces being radially oriented in an inward direction and generally forming a triangle.

[0018] - The collar comprises two finger members spaced 180° apart.

[0019] - The sleeve comprises at least one leg extending from the sleeve towards the collar in a cantilever manner, the at least one leg having a leg hook member configured to hook onto the barrel flange.

[0020] - The at least one leg comprises an inwardly facing U-shaped portion and an adjacent ramp lug.

[0021] - The sleeve includes two legs.

[0022] - The at least one finger is angularly positioned on the collar to be axially aligned with the at least one leg.

[0023] - The safety device is manufactured by a single injection molding process.

[0024] In another aspect, the present invention relates to a drug delivery device having a barrel and a piston rod, the barrel including a flange at its proximal end and an injection needle at its distal end, the piston rod including a piston flange, and the piston flange being fitted with a safety device as disclosed above.

[0025] The piston flange may include two flat portions alternating with two circular ears. Description of the Drawings

[0026] With reference to the accompanying drawings, the following is a more detailed description of aspects and embodiments of the present invention cited as examples.

[0027] Figure 1 and 2 is a perspective view of a safety device mounted on a drug delivery device according to an embodiment of the present invention;

[0028] Figure 3 is Figure 1 and 2 an exploded view of the safety device and the drug delivery device;

[0029] Figure 4 is a perspective view of the safety device and the drug delivery device during injection;

[0030] Figure 5 is a perspective view of the safety device and the drug delivery device after injection;

[0031] Figures 6 to 10 is a perspective view of the safety device without the drug delivery device. Detailed Description

[0032] The different features of the embodiments can be combined with and used together with other embodiments as long as the combined components do not conflict with or interfere with the operation of the device and components. The present invention is not limited in its application to the construction details and component arrangements set forth in the following description or illustrated in the drawings. The embodiments herein can be modified, practiced, or carried out in various ways. The wording and terminology used herein are for the purpose of description and should not be regarded as restrictive. The use of the terms "comprising", "including", or "having" and their variants herein is intended to cover the items listed thereafter and their equivalents as well as additional items. Unless otherwise restricted, the terms "connected", "coupled", "mounted" and their variants are used widely herein and cover direct and indirect connections, couplings, and mountings. Additionally, the terms "connected" and "coupled" and their variants are not limited to physical or mechanical connections or couplings. Further, terms such as distal, proximal, upper, lower, bottom, and top are relative and are for illustrative purposes only and not for limitation. The embodiments are not mutually exclusive, so the features of one embodiment can be combined with other embodiments as long as they are not contradictory. Those skilled in the art should understand that degree terms such as "substantially", "about", and "approximately" refer to a reasonable range around and including a given value as well as a range beyond the given value, e.g., the general tolerances associated with the manufacture, assembly, and use of the embodiments. When referring to a structure or feature, the term "substantially" includes features that are mostly or fully present in the structure.

[0033] The drug delivery device 100 can be a pre-filled or pre-fillable syringe. The drug delivery device 100 includes a tubular barrel 102 that defines a reservoir for containing a medical product such as a drug. The tubular barrel 102 can be made of plastic or glass material. The tubular barrel 102 has a distal shoulder 103 that is provided with a distal end 104 that projects longitudinally along a longitudinal axis A from the distal shoulder 103. The distal end 104 defines an axial passage that is in fluid communication with the reservoir and is equipped with an injection needle 101 for injecting the medical product into an injection site. The tubular barrel 102 further includes an opposite open proximal end that is provided with a flange 107. In some embodiments, the flange 107 can include two flat portions 108 that alternate with two circular ears 109.

[0034] The open proximal end receives a plunger rod 110 that is used to push a stopper 112 located inside the tubular barrel 102 to discharge the medical product from the reservoir to the injection site via the distal end 104 and the injection needle 101. The plunger rod 110 is provided with a plunger flange 114 on which the user can place a thumb.

[0035] The drug delivery device 100 may be equipped with an end cap 113 for protecting and sealing the injection needle 101 before injection.

[0036] Go to Figures 6 to 9 , the safety device 10 includes a collar 2 at its proximal end and a sleeve 3 at its distal end. The collar 2 and the sleeve 3 are connected by a flexible member, which can store mechanical energy when they are biased under a load and can release mechanical energy when the load disappears. In some embodiments, two blades 4 connect the collar 2 and the sleeve 3.

[0037] The blades 4 are configured to keep the sleeve 3 and the collar 2 axially spaced apart and substantially coaxial.

[0038] The blades 4 are further configured to bias in an outward and radial direction as the sleeve 3 and the collar 2 become axially closer, for example when a load is applied to the collar 2 while the sleeve 3 is stationary.

[0039] The configuration and dimensions of the sleeve 3 are adapted to engage with the cartridge 102. In some embodiments, the sleeve 3 includes two legs 6, which extend from the sleeve 3 towards the collar 2 in a cantilever manner. In other embodiments not shown, the safety device may include two or more legs, such as three or four legs. The legs 6 can be elastically bent in the radial direction relative to the sleeve 3.

[0040] At their free ends, each leg 6 includes a leg hook member 7, which includes an inward-facing U-shaped portion 8 and a ramp ear 9. The U-shaped portion 8 forms a groove, and the configuration and dimensions of the groove are adapted to engage into the flange 107.

[0041] In some embodiments, the legs 6 and the blades 4 are paired in twos symmetrically with respect to the A-axis. In some embodiments, as Figure 10 shown, the legs 6 and the blades 4 are arranged side by side at an angle α between 25° and 45°. Thus, two pairs of legs 6 and blades 4 define two large lateral openings.

[0042] The collar 2 is a hollow circular member having a central opening, and the configuration and dimensions of the central opening are adapted to receive the cartridge 102 and the flange 107.

[0043] As Figure 8 and 9 shown, the collar 2 includes two collar hook members 11 and two opposing finger members 12.

[0044] Each collar hook member 11 includes a tab 14, which projects axially from the collar 2 in a cantilever manner in the proximal direction. The end of the tab 14 includes an inclined ramp surface 15 radially oriented in the inward direction.

[0045] In the illustrated embodiment, the safety device 10 is provided with two grommet hook members 11 which are positioned 180 degrees from each other. In other embodiments, the safety device may be provided with three or more grommet hook members.

[0046] Each finger member 12 includes a tab 17 which axially projects in a cantilever manner from the grommet 2 in the proximal direction. The end of the tab 17 includes two inclined proximal and distal ramp surfaces 18, 19 which are radially oriented in an inward direction and which generally form a triangle. The two finger members 12 are angularly positioned on the grommet 2 to be axially aligned with the leg 6.

[0047] The safety device 10 can be manufactured by a molding process such as an injection molding process using a thermoplastic and / or a thermoplastic elastomer (TPE) or other disposable and / or recyclable materials or combinations thereof. Other suitable processes such as 3D printing can be utilized.

[0048] It will be appreciated that in some embodiments, the safety device 10 is a single-piece component which can be manufactured by a single injection molding process, which will speed up production. Accordingly, the safety device can be made of a single material to facilitate recycling of the device.

[0049] To assemble the safety device 10 to a drug delivery device (such as the drug delivery device 100 which can be a pre-filled syringe), the distal end of the drug delivery device 100 is engaged into the grommet 2; the sleeve 3 guides the barrel 102. When the end of the drug delivery device 100 is pushed into the safety device 10, the flange 107 locks into the leg hook member 7 and thus the safety device 10 is axially held onto the barrel 102. In some embodiments, the flat portion 108 of the flange locks into the U-shaped portion 8 of the leg hook member 7.

[0050] At the same time, the piston flange 114 abuts against the grommet hook member 11. The piston flange 114 slides over the inclined ramp surface 12 of each grommet hook member which deflects radially in an outward direction. This allows the piston flange 114 to lock into the proximal grommet hook member 11.

[0051] The drug delivery device 100 is axially locked by the safety device 100 by (i) its flange 107 and (ii) its piston flange 114, the flange being locked onto the leg hook member 7 and the piston flange being locked onto the grommet hook member 11.

[0052] In Figure 1 and 2 In this state as shown, the drug delivery device 100 equipped with the safety device 10 can be stored for future use. It can be noted that the safety device is not stressed and thus long-term storage will not affect its performance.

[0053] When injecting the drug contained in the drug delivery device 100, the user may first remove the end cap 113.

[0054] The drug delivery device 100 is ready for injection. The user may visually inspect the drug through the opening defined by the two pairs of legs 6 and the blade 4.

[0055] Injecting with a syringe equipped with the safety device 10 is substantially the same as injecting with a syringe equipped with a safety device according to the prior art, so it is unlikely to confuse the user and allows for user-friendly operation.

[0056] In Figures 1 to 5 the exemplary use illustrated in, the user may generally press the thumb on the piston rod flange 114 while the user places one finger (usually the index finger) on one of the circular ears 109 and one finger (usually the middle finger) on the other circular ear 109 to apply a thrust to the piston rod flange 114.

[0057] As the injection proceeds, the piston rod flange 114 moves closer to the flange 107.

[0058] Since the collar 2 is locked to the piston rod flange 114 and the flange 107 is locked to the legs, the blade 4 is biased in the radially outward direction as shown in Figure 7 and stores mechanical energy.

[0059] At the end of the injection, the finger member 12 abuts against the inclined ramp surface 9 of the leg hook member 8. By an additional push on the piston rod 114, the inclined distal ramp surface 19 of the finger 12 abuts against the ramp ear 9 provided at the end of the leg hook member 7. Thus, the leg hook member 7 is forced to deflect outwardly, releasing the flange 107. The blades 6 freely release their mechanical energy and axially push the sleeve 3 in the distal direction. Then, the needle 101 is surrounded by the sleeve 3 and is protected.

[0060] At the same time, the flange 107 is locked into the distal inclined surface 19 of the finger member 12.

[0061] The protection device 10 thus achieves a substantially permanent locking of the tubular body 12 on the tip 101 of the needle without any input operation by the user, because the blade 4 acquires mechanical energy during the injection, which is used to move the safety device 10 to the safe position, in which the sleeve 3 surrounds the needle 101.

[0062] The terms used herein are for the purpose of describing particular aspects only and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should be further understood that when used herein, the terms "comprises" and / or "comprising" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0063] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0064] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another, as illustrated in the figures. It should be understood that these terms and those discussed above are intended to cover different orientations of the device other than the orientations depicted in the figures. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intervening elements. In contrast, when an element is referred to as "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0065] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should be further understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense, unless expressly defined otherwise herein.

[0066] It should be understood that the present disclosure is not limited to the aspects described above and illustrated in the figures; rather, those skilled in the art will recognize that changes and modifications can be made within the scope of the appended claims.

Claims

1. A safety device (10) for attachment to a drug delivery device (100), the drug delivery device having a barrel (102) and a piston rod (110), the barrel comprising a flange (107) at its proximal end and an injection needle (101) at its distal end, the piston rod having a piston flange (114), the safety device (10) comprising: A collar (2), the collar having at least one locking member configured to lock the collar (2) relative to the piston flange (114); A sleeve (3) configured to slide on the barrel (102), the sleeve (3) having at least one locking member, the at least one locking member of the sleeve being configured to lock the sleeve (3) relative to the barrel (102); A flexible member connecting the collar (2) and the sleeve (3) and maintaining the collar (2) and the sleeve (3) axially spaced apart, the flexible member being configured to undergo energy-storing elastic deformation when the collar (2) is pushed towards the sleeve (3) and to release the energy when the sleeve is unlocked from the barrel; The locking member of the sleeve comprises at least one leg (6) extending in a cantilever manner from the sleeve (3) towards the collar (2), the at least one leg (6) having a leg hook member (7) configured to hook onto the flange (107) of the barrel, the leg hook member being operable to unlock the sleeve (3) from the barrel (102) so as to release the energy stored in the flexible member when the sleeve (3) is unlocked from the barrel (102).

2. The safety device according to claim 1, wherein, The flexible member comprises at least one elastic blade (4) connecting the sleeve (3) and the collar (2).

3. The safety device according to any one of claims 1 to 2, wherein, The collar (2) comprises at least one collar hook member (11) configured to lock onto the piston flange (107), the collar hook member (11) axially protruding in a cantilever manner from the collar (2) in a proximal direction, the collar hook member having an inclined ramp surface (15) at its free end.

4. The safety device according to claim 3, wherein, The collar (2) comprises two collar hook members (11) spaced 180° apart.

5. The safety device according to any one of claims 1 to 4, wherein, The collar (2) comprises at least one finger member (12) protruding in a cantilever manner from the collar (2) in a distal direction, the finger member (12) having an inclined proximal ramp surface and a distal ramp surface (18, 19), the proximal ramp surface and the distal ramp surface (18, 19) being radially oriented in an inward direction and generally forming a triangle.

6. The safety device according to claim 5, wherein, The collar (2) comprises two finger members (12) spaced 180° apart.

7. The safety device according to any one of claims 1 to 6, wherein, The at least one leg (6) comprises an inwardly facing U-shaped portion (8) and an adjacent ramp ear (9).

8. The safety device according to any one of claims 1 to 7, wherein, The sleeve (3) comprises two legs (6).

9. The safety device according to any one of claims 1 to 8, wherein, The at least one finger member (12) is angularly positioned on the collar (2) to be axially aligned with the at least one leg (6).

10. The safety device according to any one of claims 1 to 9, wherein, The safety device (10) is manufactured by a single-shot injection molding process.

11. A drug delivery device (100), the drug delivery device having a barrel (102) and a piston rod (110), the barrel comprising a flange (107) at its proximal end and an injection needle (101) at its distal end, the piston rod comprising a piston flange (114), the piston flange being fitted with a safety device (100) according to any one of claims 1 to 10.

12. The drug delivery device (100) according to claim 11, wherein, The piston flange comprises two flat portions (108) alternating with two circular ears (109).

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