HOUSING ELEMENT AND DRUG DELIVERY DEVICE HEREWITH

Abstract

The present disclosure refers to a housing element for a drug delivery device. The housing element comprises longitudinal axis and defines an interior space for receiving components of a drive mechanism of the drug delivery device and at least a portion of a cartridge of the drug delivery device. The housing element comprises an engagement feature for axially constraining the housing element to a cartridge holder of the drug delivery device. In order to constrain the cartridge in the housing element, it further comprises at least one crush web protruding radially inwards into the interior space. The at least one crush web is angled relative to the longitudinal axis of the housing element by at least 3° such that when the cartridge is introduced into the interior space the at least one crush web folds radially outwards.

Claims

1-15. (canceled)

16. A housing element for a drug delivery device, the housing element comprising a longitudinal axis and defining an interior space for receiving components of a drive mechanism of the drug delivery device and at least a portion of a cartridge of the drug delivery device, wherein the housing element comprises an engagement feature for axially constraining the housing element to a cartridge holder of the drug delivery device, the housing element further comprising at least one crush web protruding radially inwards into the interior space, wherein the at least one crush web is angled relative to the longitudinal axis of the housing element by at least 3° such that when the cartridge is introduced into the interior space the at least one crush web folds radially outwards.

17. The housing element according to claim 16, wherein the at least one crush web is angled relative to the longitudinal axis of the housing element by at least 5°.

18. The housing element according to claim 16, wherein the at least one crush web is angled relative to the longitudinal axis of the housing element by about 15°.

19. The housing element according to claim 16, wherein the housing element comprises at least one lateral aperture, wherein the at least one crush web is located adjacent and/or coincident with the at least one lateral aperture, such that when the cartridge is introduced into the interior space the at least one crush web folds into the at least one lateral aperture.

20. The housing element according to claim 16, wherein the housing element comprises three crush webs spaced 120° apart.

21. The housing element according to claim 16, further comprising at least one support structure extending radially inwards into the interior space thereby reducing the diameter for receiving the cartridge of the drug delivery device, wherein the at least one crush web is located on the at least one support structure, such that when the cartridge is introduced into the interior space the at least one crush web folds radially outwards.

22. The housing element according to claim 21, wherein the at least one support structure comprises two pairs of radially inwardly protruding walls, wherein one crush web is located on each of the four walls.

23. The housing element according to claim 22, wherein the pairs of radially inwardly protruding walls are spaced 180° apart.

24. The housing element according to claim 16, wherein the at least one crush web has a thickness of at least 0.1 mm.

25. The housing element according to claim 16, wherein the at least one crush web has a thickness of about 0.15 mm.

26. The housing element according to claim 16, wherein the housing element has a reduced wall thickness locally where the at least one crush web joins the housing element.

27. The housing element according to claim 16, wherein the housing element comprises an inner thread for engaging a threaded piston rod of the drug delivery device.

28. The housing element according to claim 16, wherein the housing element comprises an outer thread for engaging a dose dial sleeve of the drug delivery device.

29. The housing element according to claim 16, wherein the housing element comprises inner axially extending splines for engaging a drive sleeve of the drug delivery device.

30. The housing element according claim 16, further comprising a distal body portion having a larger diameter for receiving at least a portion of the cartridge of the drug delivery device and a proximal body portion having a smaller diameter compared with the distal body portion for receiving components of the drive mechanism of the drug delivery device, wherein the distal body portion and the proximal body portion are connected to each other by a radially extending flange wall.

31. The housing element according to claim 16, wherein the engagement feature is a circumferentially extending bead or groove provided on an outer surface of the housing element.

32. A drug delivery device comprising: a cartridge containing a medicament; a drive mechanism for driving a piston in the cartridge; a housing element comprising a longitudinal axis and defining an interior space for receiving components of the drive mechanism of the drug delivery device and at least a portion of the cartridge of the drug delivery device, wherein the housing element comprises an engagement feature for axially constraining the housing element to a cartridge holder of the drug delivery device, the housing element further comprising at least one crush web protruding radially inwards into the interior space, wherein the at least one crush web is angled relative to the longitudinal axis of the housing element by at least 3° such that when the cartridge is introduced into the interior space the at least one crush web folds radially outwards; and an outer body axially constrained to the housing element by the engagement feature.

33. The drug delivery device according to claim 32, wherein the outer body encloses the housing element and the cartridge.

34. The drug delivery device according to claim 32, wherein the cartridge has a nominal outer diameter which is, when the cartridge is introduced into the interior space of the housing element, in radial interference with the at least one crush web.

35. The drug delivery device according to claim 32, wherein the housing element comprises at least one lateral aperture, wherein the at least one crush web is located adjacent and/or coincident with the at least one lateral aperture, such that when the cartridge is introduced into the interior space the at least one crush web folds into the at least one lateral aperture.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0047] Non-limiting, exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0048] FIG. 1 shows a perspective view of a housing for a drug delivery device;

[0049] FIG. 2 shows a cut-away view on the inner side of the housing of FIG. 1;

[0050] FIG. 3 shows a perspective view of a detail of a second housing for a drug delivery device;

[0051] FIG. 4 shows a section through the housing of FIG. 3;

[0052] FIG. 5 shows a side view of the housing of FIG. 3;

[0053] FIG. 6 shows a perspective view on a third housing for a drug delivery device;

[0054] FIG. 7 shows a perspective view on the housing of FIG. 6;

[0055] FIG. 8 shows a sectional view on a fourth housing for a drug delivery device; and

[0056] FIG. 9 shows a graph of the force exerted by a crush web depending on the axial travel of a cartridge.

DETAILED DESCRIPTION

[0057] In the Figures, identical elements, identically acting elements or elements of the same kind may be provided with the same reference numerals.

[0058] The terms “axial”, “radial”, or “circumferential” as used herein may be used with respect to a main longitudinal axis I of the device, the cartridge, the housing or the cartridge holder, e.g., the axis which extends through the proximal and distal ends of the cartridge, the cartridge holder or the drug delivery device.

[0059] “Distal” is used herein to specify directions, ends or surfaces which are arranged or are to be arranged to face or point towards a dispensing end of the drug delivery device or components thereof and/or point away from, are to be arranged to face away from or face away from the proximal end. On the other hand, “proximal” is used to specify directions, ends or surfaces which are arranged or are to be arranged to face away from or point away from the dispensing end and/or from the distal end of the drug delivery device or components thereof. The distal end may be the end closest to the dispensing and/or furthest away from the proximal end and the proximal end may be the end furthest away from the dispensing end. A proximal surface may face away from the distal end and/or towards the proximal end. A distal surface may face towards the distal end and/or away from the proximal end. The dispensing end may be the needle end where a needle unit is or is to be mounted to the device, for example.

[0060] A first housing is depicted in FIGS. 1 and 2. These figures schematically show a housing element 1 for use in a drug delivery device. The housing element 1 comprises a proximal body portion 2 having a smaller diameter and a distal body portion 3 having the larger diameter compared with the proximal body portion 2. The proximal body portion 2 and the distal body portion 3 are connected by a flange-like wall extending substantially perpendicular to the longitudinal axis I. The distal body portion 3 is provided with a circumferentially extending groove 4 which forms an engagement feature for axially constraining the housing 1 to another component part of the drug delivery device, for example for axially constraining the housing element 1 to a cartridge holder (not shown in FIGS. 1 and 2).

[0061] The housing element 1 may be an internal housing or inner body of a drug delivery device, for example an internal component part housing components of a drive mechanism and/or a dose setting mechanism of the drug delivery device. As an alternative, the housing element 1 may be an external housing or outer body of the drug delivery device, i.e., an outer shell encasing all components of the drug delivery device.

[0062] As shown in FIGS. 1 and 2, the distal body portion 3 comprises an aperture 5. In the exemplary embodiment, the aperture 5 is substantially rectangular and angles relative to the longitudinal axis I of the housing 1. However, the shape and orientation of the aperture 5 is not limited to the depicted example. In addition, the may be more than one aperture 5 as shown in FIGS. 1 and 2.

[0063] FIG. 2 shows a partially cut away view on the inner side of the distal body portion 3. A crush web 6 is provided adjacent to the aperture 5 on the inner side of the distal body portion 3. In other words, the crush web 6 extends substantially radially inwards. As can be seen in FIG. 2, the crush web 6 extends in a plane which is angled relative to the longitudinal axis I of the housing by about 15°. The radially inwards facing edge of the crush web 6 extends in a cylindrical plane which is parallel to the cylindrical distal body portion 3. In other words, the radially inwards facing edge is not tapered with respect to the distal body portion 3. Further, in the exemplary embodiment, the crush web 6 has a substantially constant thickness of about 0.15 mm. FIG. 2 shows the crush web significantly thicker for illustration purposes.

[0064] The interior space of the distal body portion 3 of the housing element 1 is intended to receive a proximal end of a cartridge (not shown) during assembly of a drug delivery device. The crush web 6 is arranged such that the nominal outer diameter of the cartridge is in a radial interference with the crush web 6. Thus, when the cartridge is assembled, the crush web 6 folds/curls into the aperture 5 maintaining axial and radial constraint on the cartridge at all tolerance conditions.

[0065] One or more crush webs may be moulded into the housing element 1 of a device, wherein one side of a crush rib 6 is adjacent/coincident with the aperture 5 through the side wall of the housing element 1 and angled relative to the longitudinal axis I of the housing element 1 by at least 3° and preferably 15° so that when the cartridge is assembled, the web 6 folds/curls into the aperture 5, maintaining axial and radial constraint on the cartridge at all tolerance conditions. An example of such an embodiment comprising three crush webs 6 spaced 120° apart is shown in the exemplary embodiment of FIGS. 3 to 5. As can be seen for example in FIG. 4, the distal body portion 3 may have reduced wall thickness locally where the respective crush web 6 joins of the outer wall of the distal body portion 3. Further, FIG. 4 shows a threaded interface 7 provided inside the proximal body portion 2. This threaded interface may be suitable for engagement with a threaded piston rod or the like.

[0066] In FIG. 4, a cartridge is indicated by two concentrical circles D1 (outer diameter of the cartridge) and D2 (inner diameter of the cartridge). As can be seen, the crush ribs 6 are designed to be in interference with the glass of the cartridge and deform during assembly of the mechanism.

[0067] While the first and second embodiments depicted in FIGS. 1 to 5 show a housing element 1 suitable for receiving a 3 ml cartridge, the at least one crush web 6 according to the present disclosure may be provided in housings for other cartridge sizes, too. An example of a housing element 1 suitable for a 1.5 ml cartridge variant is depicted in the third embodiment of FIGS. 6 and 7. While the diameter of the distal body portion 3 is identical with the diameter in the second embodiment of FIGS. 3 to 5, the outer diameter of the cartridge is substantially smaller in the third embodiment. The reduced diameter of the cartridge is indicated in FIG. 7 by the external diameter D1 and the internal diameter D2 of the cartridge.

[0068] In this third embodiment, the distal body portion 3 is provided with two pairs of radially extending support walls 8 which are positioned 180° apart. A crush web 6 is provided at the radially inwards facing edge of each of the four support walls 8. When the cartridge is inserted into the housing element 1, the crush webs 6 interfere with the outer diameter of the cartridge and fold the crush webs 6 away in the space between the inner edge of the support walls 8 and the distal body portion 3.

[0069] FIG. 8 shows a fourth embodiment, wherein the housing element 1 is an inner body retained in an outer body or shell 9. The inner housing element 1 is axially constrained to the outer body 9 by an inwardly extending bead of the outer body 9 engaging the grooves 4 on the distal body portion 3 of the inner housing element 1. The outer body 9 extends from the distal end to the proximal end of the drug delivery device and houses not only the dose setting and drive mechanism but also functions as a cartridge holder. As an alternative, a separate cartridge holder may be provided attached to the housing element 1 and/or to the outer body 9.

[0070] The inner housing element 1 has a threaded interface on the outside of the proximal body portion 2 for engaging a dose dial sleeve or a number sleeve 10. Further, a splined interface provided on the inner side of the proximal body portion 2 engages and guides a driver 11 of the drug delivery device. Still further, a threaded piston rod 12 is guided in the threaded interface 7.

[0071] In the condition depicted in FIG. 8, a cartridge 13 with a bung or piston 14 is inserted into the device such that the proximal end of the cartridge 13 is received in the distal body portion 3 of the inner housing element 1. By inserting the cartridge 13 into the distal body portion 3, crush webs 6 are deformed, thereby constraining the cartridge 13 axially and radially within the inner housing element 1.

[0072] FIG. 9 is a graph comparing the force exerted by a tapered prior art rib (dotted line) and of the force exerted by a crush web according to the present disclosure (continuous line) as the cartridge 13 is inserted into the housing element 1. While a tapered prior art rib results in a gradually increasing force exerted on the cartridge, a crush webaccording to the present disclosure exerts a substantially constant force on the cartridge. In more detail, after initial engagement of the crush web 6, at about 0.2 mm of relative travel between the cartridge 13 and the crush web 6, the force has risen to about 3 N. for the next 1.2 mm of travel it only raises to just under 4 N. This is ideal as it can accommodate tolerance of +/−0.6 mm in the assembly height of the end face of the cartridge 13 relative to the housing element 1 whilst still applying 3-4 N per crush web 6. The crush webs 6 deform when the cartridge 13 is inserted and tend to fold out of the way due to angled geometry. As the crush webs 6 are only 0.15 mm thick, this requires a low assembly force and this assembly force does not change significantly as the cartridge is inserted further axially.

[0073] The low axial force to assemble a cartridge prevents glass breakage during assembly. Further, this maintains good dose accuracy by preventing cartridge movement when attaching a needle (not shown) and shows an improved impact test performance with significant reduction in the instances of glass breakage when using these crush webs 6 to retain the cartridge 13.

REFERENCE NUMERALS

[0074] 1 (inner) housing element [0075] 2 proximal body portion [0076] 3 distal body portion [0077] 4 engagement groove [0078] 5 aperture [0079] 6 crush web [0080] 7 threaded interface [0081] 8 wall [0082] 9 outer body (shell) [0083] 10 number sleeve [0084] 11 driver [0085] 12 piston rod [0086] 13 cartridge [0087] 14 piston [0088] D1 outer diameter of the cartridge [0089] D2 inner diameter of the cartridge [0090] I longitudinal axis