A re-usable injection device with a protective cap

Abstract

A re-usable injection device having a housing structure (10) which is releasably attachable to a cartridge assembly (20) and with a releasably mountable protective cap (30) comprising two separate coupling means (31, 32). A first coupling means (31) is adapted to engage first engaging means (13) on the housing structure (10) when the cartridge assembly (20) is disconnected from the housing structure (10), and a second coupling means (32) adapted to engage second engaging means (24) on the cartridge assembly (20) when the cartridge assembly (20) is connected to the housing structure (10).

Description

[0001] 240054W001

[0002] 1

[0003] A Re-usable I njection Device with a Protective Cap

[0004] THE TECHNICAL FIELD OF THE INVENTION:

[0005] 5 The invention relates to a re-usable injection device for administering a liquid drug. Such reusable injection device usually comprises a housing structure and a cartridge assembly exchangeably connectable to the housing structure. The present invention especially relates to such injection device further having a protective cap to cover the distal part of the injection device when the injection device is not in use. The present invention also relates to a protective cap for such injection device.

[0006] DESCRIPTION OF RELATED ART:

[0007] Injection devices for subcutaneous injections are widely used to self-administer a long range 15 of different liquid drugs. In particular, pen-shaped injection devices have proven to provide an accurate, convenient and often discrete way of administering liquid drugs.

[0008] Typically, injection devices use a filled cartridge i.e. a cartridge filled with the liquid drug under sterile conditions at the facility of the manufacturer. Most filled cartridges for such injection 20 systems contain either 1.5 ml or 3.0 ml of liquid drug. The cartridge is typically in the form of a cylindrical transparent ampoule often made from glass. Such cartridge is usually closed at one end by a needle pierceable septum and at the opposite end by a movable plunger designed to be moved toward the pierceable septum thus decreasing the volume of the cartridge compartment as the displaced liquid drug flows out through a double pointed injection needle having its rear end pierced through the septum.

[0009] Such cartridge-based Injection devices are generally divided into two different main groups being distinctly different; one group being pre-filled or disposable injection devices and the other group being re-usable or durable injection devices. The present invention concerns the 30 latter group.

[0010] A pre-filled or disposable injection device has an embedded cartridge which is irreversibly secured inside the injection device and cannot be replaced. When the cartridge is empty, or at240054W001

[0011] 2

[0012] least when the injectable content of liquid drug in the cartridge has been used, the entire injection device is disposed of. Since the pre-filled or disposable injection device is to be discarded when empty, this type of device will typically not include a reset mechanism to return the piston rod to its initial position as this is not needed.

[0013] 5

[0014] A re-usable or durable injection device usually has a cartridge or cartridge assembly which easily can be replaced by the user such that the same injection device can be used for a series of cartridges or cartridge assemblies. Since the injection device is repeatedly used, it must be possible to return the piston rod to its initial position each time the cartridge or cartridge assembly is replaced and hence throughout the lifetime of the injection device.

[0015] An example of a cartridge assembly is disclosed in figure 6 to 8 of US 5,334,162 which discloses a glass cartridge irreversibly embedded in a plastic housing thus making up the cartridge assembly. In this example, the cartridge assembly is connectable to the housing 15 structure by a threaded connection and once the injectable content of the cartridge has been ejected, the user replaces the cartridge assembly with a new and fresh cartridge assembly and discards the whole of the used cartridge assembly.

[0016] Most pen-shaped injection devices are further provided with a releasable protective cap 20 covering the distal part of the injection device when not in use as e.g. known from traditional fountain pens. Such protective caps usually engage the pen-shaped injection device by having a circumferential sunken or recessed groove provided proximally on the inner surface to engage with one or more protrusions provided on the outer surface of the pen-shaped injection device.

[0017] 25

[0018] An example of a re-usable multi-use fixed dose injection device with a protective cap is provided in PCT patent application No. PCT / EP2025 / 080742 filed October 23, 2025. An example of such injection device is depicted on the figures 1A-C in the present application and comprises a housing structure and a cartridge assembly connectable to the housing structure.

[0019] 30 Both the housing structure and the cartridge assembly is, in this example, provided with protrusions for engaging a circumferential sunken or recessed groove inside a protective cap such that the protective cap can be connected either to the housing structure or to the cartridge assembly. However, the protective cap needs to be rather long to reach onto the protrusions provided on the housing structure when no cartridge assembly is mounted. Hence, when such 35 long protective cap is connected to the protrusions on the cartridge assembly, the full length240054W001

[0020] 3

[0021] of the injection device including the protective cap is unnecessary long which may cause inconvenience for a user wanting to transport the injection device discretely around e.g. in a pocket or in a small bag.

[0022] 5 DESCRIPTION OF THE INVENTION:

[0023] It is an object of the present invention to eliminate or reduce one or more drawbacks of the prior art and to provide a useful alternative to the known solutions such that the one and same protective cap can fit onto either the cartridge assembly or onto the housing structure in a more optimized manner.

[0024] In a first aspect, the invention is defined in claim 1. Advantageous embodiments are further defined in the dependent claims. Although the re-useable injection device exemplified in the present description is a multi-use fixed dose injection device, any re-usable injection device is 15 meant to be the subject of the claims.

[0025] Accordingly, in one aspect the present invention relates to a re-usable injection device with a releasably mountable protective cap, which re-usable injection device comprises:

[0026] a housing structure containing a dose selection- and expelling mechanism, and 20

[0027] a cartridge assembly irreversibly securing a cartridge, the cartridge assembly being exchangeably connectable at a distal end of the housing structure,

[0028] wherein the housing structure is provided with first engaging means for releasably engaging the protective cap for releasably mounting the protective cap at the distal end of the housing structure, and

[0029] the cartridge assembly is provided with second engaging means for releasably engaging the protective cap for releasably mounting the protective cap at a distal end of the cartridge 30 assembly.

[0030] According to this aspect, the protective cap comprises two separate coupling means:

[0031] a first coupling means adapted to engage the first engaging means on the housing structure when the cartridge assembly is disconnected from the housing structure, and240054W001

[0032] 4

[0033] a second coupling means adapted to engage the second engaging means on the cartridge assembly when the cartridge assembly is connected to the housing structure.

[0034] 5

[0035] Hence, when the protective cap is provided with two separate coupling means, these can be provided in various positions such that the same protective cap can be optimized to be used on an injection device both with and without the cartridge assembly being mounted.

[0036] The first coupling means preferably embodied as a groove or as protrusions thus engages with the housing structure, and the second coupling means preferably embodied as a groove or a recessed track engages with the cartridge assembly. In this way it is possible to optimize especially the length of the protective cap.

[0037] 15 In one example, the first coupling means are provided in or on the distal part of the protective cap and preferably located on one or more axial arms extending from a distal end-surface of the protective cap. However, any position at the distal part is understood to be covered by the claims.

[0038] 20 Alternatively, the first coupling means are provided in or on the proximal part of the protective cap. In this example, the first coupling means are preferably a number of outwardly pointing protrusions, such as one or more raised protrusions protruding from a radially inwards facing surface or from a radially outwards facing surface.

[0039] 25 The second coupling means can, like the first coupling means, be provided in any position but are preferably provided in the proximal part of the protective cap and is preferably shaped as a recessed track or groove.

[0040] The aim of the exemplified invention is thus to provide a re-usable injection device wherein the 30 full physical length of the injection device with the protective cap mounted is approximately the same with the cartridge assembly attached as without the cartridge assembly attached.

[0041] Hence, in a first situation where the protective cap is mounted on the housing structure which would normally be the case when the injection device is presented to the user and in a second 35 situation where the cartridge assembly is mounted in the situation of use, the full length of the injection device with the protective cap are approximately the same. It would preferably be240054W001

[0042] 5

[0043] desired that the full length of the injection device in both above situations are the same to a degree wherein the injection device would fit into the same box in both situations.

[0044] In some embodiments, the cartridge assembly comprises a cartridge having a movable plunger 5 For such embodiments, the dose selection- and expelling mechanism may comprise a piston rod configured for movement from a proximal first position towards a distal second position so as to move the plunger in the distal direction.

[0045] In such embodiments, the housing structure may be provided such that it defines a proximal main body and a longitudinal distal extension fixedly attached to or being integrally formed with the main body so that the longitudinal tubular extension extends in the distal direction from the main body. The longitudinal extension may be formed to encircle the piston rod and axially overlap the piston rod when the piston rod assumes the distal second position.

[0046] 15 In a second aspect the present invention relates to a protective cap adapted to be releasably mountable on a re-usable injection device which comprises the below elements:

[0047] a housing structure containing a dose selection- and expelling mechanism,

[0048] a cartridge assembly irreversibly securing a cartridge and being exchangeably 20 connectable to the housing structure,

[0049] wherein the housing structure is provided with first engaging means for releasably engaging the protective cap, and

[0050] the cartridge assembly is provided with second engaging means for releasably engaging the protective cap.

[0051] The protective cap according to the second aspect comprises two separate coupling means, wherein:

[0052] 30 a first coupling means is adapted to engage the first engaging means on the housing structure when the cartridge assembly is disconnected from the housing structure, and240054W001

[0053] 6

[0054] a second coupling means is adapted to engage the second engaging means on the cartridge assembly when the cartridge assembly (20) is connected to the housing structure.

[0055] 5 By having two distinct and separate coupling means, the protective cap can be fitted onto the injection device both when the cartridge assembly is not mounted an when the cartridge assembly is mounted.

[0056] In one example of the protective cap the first coupling means are provided in the distal part of the protective cap.

[0057] In a second example the first coupling means are provided in the proximal part of the protective cap.

[0058] 15 However, in both these examples, the second coupling means are preferably provided in the proximal part of the protective cap.

[0059] DEFINITIONS:

[0060] An “injection pen” or “pen for injection” is typically an injection apparatus having an oblong 20 or elongated shape somewhat like a pen for writing. Although such pens usually have a tubular cross-section, they could easily have a different cross-section such as triangular, rectangular or square or any variation around these geometries.

[0061] The term “Needle Cannula” is used to describe the actual conduit performing the penetration of the skin during injection. A needle cannula is usually made from a metallic material such as e.g. stainless steel and connected to a hub to form a complete injection needle also often referred to as a “needle assembly” or simply “injection needle”. A needle cannula could however also be made from a polymeric material or a glass material. The hub also carries the connecting means for connecting the needle assembly to an injection apparatus and is usually 30 moulded from a suitable thermoplastic material. The “connection means” could as examples be a luer coupling, a bayonet coupling, a threaded connection or any combination thereof.

[0062] The term “Needle unit” is used to describe one single needle assembly carried in a container. Such container usually has a closed distal end and an open proximal end which is sealed by240054W001

[0063] 7

[0064] a removable seal. The interior of such container is usually sterile such that the needle assembly is ready to use. Needle units specially designed for pen injection systems are defined in ISO standard No. 11608, part 2, and are often referred to as “pen needles”. Pen needles are usually double pointed having a front-end for penetrating through the skin of a user and a back- 5 end for penetrating into the cartridge containing the drug such that liquid communication is established during injection.

[0065] As used herein, the term “Liquid drug” is meant to encompass any drug-containing flowable medicine capable of being passed through a delivery means such as a hollow needle cannula in a controlled manner, such as a liquid, solution, gel or fine suspension. Representative drugs include pharmaceuticals such as peptides, proteins (e.g. insulin, insulin analogues and C- peptide), and hormones, biologically derived or active agents, hormonal and gene-based agents, nutritional formulas and other substances in both solid (dispensed) or liquid form.

[0066] 15 “Cartridge” is the term used to describe the container or ampoule actually containing the drug which are often referred to as the primary packing as it is in direct contact with the liquid drug. Cartridges are usually made from glass but could also be moulded from a suitable polymer. A cartridge or ampoule is preferably sealed at one end by a pierceable membrane referred to as the “septum” which can be pierced e.g. by the non-patient end of a needle cannula. Such 20 septum is usually self-sealing which means that the opening created during penetration seals automatically by the inherent resiliency of the septum material once the needle cannula is removed from the septum. The opposite end of the cartridge is typically closed by a movable “plunger” which is a piston-like element made from rubber or a suitable polymer. The plunger is during use slidable moved inside the cartridge preferably in a distal direction. The space 25 between the pierceable membrane and the movable plunger holds the liquid drug which is pressed out as the plunger decreased the volume of the space holding the liquid drug. The cartridges used for both pre-filled injection devices and for reusable injections devices are typically factory filled by the manufacturer with a predetermined volume of a liquid drug. A large number of the cartridges currently available contains either 1 ,5 ml or 3 ml of liquid drug. 30

[0067] Since a cartridge usually has a narrower distal neck portion into which the plunger cannot be moved not all of the liquid drug contained inside the cartridge can actually be expelled. The term “initial quantum” or “substantially used” therefore refers to the injectable content contained in the cartridge and thus not necessarily to the entire content.

[0068] 35240054W001

[0069] 8

[0070] By the term “Pre-filled injection device” is meant an injection device in which the cartridge containing the liquid drug is pre-filled by the manufacture of the injection device and permanently embedded in the injection device such that it cannot be removed without permanent destruction of the injection device. Once the pre-filled amount of liquid drug in the 5 cartridge is used, the user normally discards the entire injection device. Usually, the cartridge which has been filled by the manufacturer with a specific amount of liquid drug is secured in a cartridge holder which is then permanently connected in a housing structure such that the cartridge cannot be exchanged.

[0071] This is in opposition to a “Reusable injection device” in which the user can himself change the cartridge containing the liquid drug whenever it is empty. Pre-filled injection devices are usually sold in packages containing more than one injection device whereas reusable injection devices are usually sold one at a time. When using pre-filled injection devices an average user might require as many as 50 to 100 injection devices per year whereas when using reusable 15 injection devices one single injection device could last for several years, however, the average user would require 50 to 100 new cartridges per year.

[0072] For some reusable or durable injection devices, the cartridge is permanently and irreversibly embedded in a plastic shell or the like which is removable attached to the housing of the 20 injection device. Such plastic shell comprising a cartridge permanently embedded therein is often referred to as a “Drug container unit”. After use, when the cartridge in the drug container unit is empty, the user discards the whole drug container unit and replaces it with a new and fresh drug container unit containing the irreversibly secured cartridge (or similar container) with liquid drug sufficient for a plurality of injections.

[0073] 25

[0074] All references, including publications, patent applications, and patents, cited herein are incorporated by reference in their entirety and to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0075] 30

[0076] All headings and sub-headings are used herein for convenience only and should not be constructed as limiting the invention in any way.

[0077] The use of any and all examples, or exemplary language (e.g. such as) provided herein, is 35 intended merely to better illuminate the invention and does not pose a limitation on the scope240054W001

[0078] 9

[0079] of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0080] The citation and incorporation of patent documents herein is done for convenience only and 5 does not reflect any view of the validity, patentability, and / or enforceability of such patent documents.

[0081] This invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law.

[0082] BRIEF DESCRIPTION OF THE DRAWINGS:

[0083] The invention will be explained more fully below in connection with a preferred embodiment 15 and with reference to the drawings in which:

[0084] Figure 1 A-B show an example of a prior art injection device,

[0085] Figure 2A-C show different views of the housing structure,

[0086] 20

[0087] Figure 3A-C show different views of the cartridge assembly,

[0088] Figure 4A-C show different views of the protective cap,

[0089] Figure 5A-B show the protective cap mounted on the housing structure,

[0090] Figure 6A-B show the cartridge assembly mounted on the housing structure,

[0091] Figure 7A-B show the protective cap mounted on the cartridge assembly,

[0092] 30

[0093] Figure 8 shows a different example of the protective cap,

[0094] Figure 9 shows a different example of the housing structure,240054W001

[0095] 10

[0096] Figure 10 shows the cartridge holder part without cartridge,

[0097] Figure 11 shows the protective cap of figure 8 mounted on the housing structure of figure 9, and

[0098] 5

[0099] Figure 12 shows the protective cap of figure 8 mounted on the cartridge holder part.

[0100] 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.

[0101] DETAILED DESCRIPTION OF EMBODIMENT:

[0102] When in the following terms as “upper” and “lower”, “right” and “left”, “horizontal” and “vertical” 15 or similar relative expressions are used, these only refer to the appended figures and not necessarily to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as their relative dimensions are intended to serve illustrative purposes only.

[0103] 20 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 supporting the injection needle, whereas the term “proximal end” is meant to refer to the opposite end carrying the dose selection button as indicated in figure 1. Distal and proximal is meant to be along an axial orientation extending along the longitudinal axis (X) of the injection device as also shown in figure 1.

[0104] When referring to clockwise and anti or counter-clockwise in the following examples it is understood that the injection device is viewed from a position distal to the injection device. Clockwise is thus a rotation following the arms on an ordinary clock rotating towards the right when e.g. moving from 12 O'clock to 3 O'clock, and wherein counter-clockwise is a rotation in 30 the opposite direction.

[0105] To explain the various movements which take place in the injection device described in the example, the following terminology are used throughout the following detailed description.240054W001

[0106] 11

[0107] “Translational movement” is meant to be a strictly linear movement without any rotation.

[0108] “Rotational movement” is any movement of rotation around a centre which centre can be a 5 centre point i.e. in one planar or a centre axis i.e. having a longitudinal extension.

[0109] “Axial movement” means any movement in an axial direction. Such movement can be a strictly translational movement or include a rotational movement which thus makes it a “Helical movement” as this is meant to be an axial movement combined with a rotational movement. By “axial” is meant in a lengthwise direction but not necessarily along a straight line. “Radial” is meant to be at an angle to the axial direction. The angle is not necessarily 90° hence the radial direction is not necessarily perpendicular to the axial direction.

[0110] “Telescopic” is meant to cover the situation in which a movable element moves out from, and / or 15 into, a base element. The telescopic movement can be either translational or include a rotation thus making the telescopic movement helical.

[0111] Figure 1A-B discloses a prior art re-usable multi-use fixed dose injection device with a cartridge assembly as disclosed in PCT patent application No. PCT / EP2025 / 080742. The 20 outer shell of the injection device comprises a housing structure 1 containing the dose selection- and expelling mechanism and a cartridge assembly 2 containing the liquid drug.

[0112] Prior to use, the distal part on the injection device is covered by a protective cap 3 which the user needs to remove before an injection can be performed. Following the injection, the user 25 would normally re-connect the protective cap 3 to the injection device.

[0113] The protective cap 3 is proximally on an inner surface provided with a circumferential sunken or recessed groove 6 as shown in figure 1B which can either engage the one or more protrusions 4 provided on the housing structure 1 or the one or more protrusions 5 provided 30 on the cartridge assembly 2 as disclosed in figure 1 A.

[0114] Hence, the protective cap 3 needs to have a substantial length in order to be able to reach the protrusions 4 provided on the housing structure 1 when no cartridge assembly 2 is connected to the housing structure 1.

[0115] 35240054W001

[0116] 12

[0117] When the injection device is in use, the user has connected the cartridge assembly 2 to the housing structure 1 using a bayonet interface or similar interface. However, when the protective cap 3 thereafter is connected by using the protrusions 5 provided on the cartridge assembly 2, the overall length of the injection device including the protective cap 3 is rather long making it 5 more difficult to discretely transport the injection device around.

[0118] Housing Structure

[0119] In the present invention, the housing structure 10 in a first embodiment is disclosed in different views in the figures 2A-C and comprises a longitudinal tubular extension 11 extending in the distal direction from the main body. This longitudinal extension 11 is preferably moulded as an integral part of the housing structure 10. By having such longitudinal extension 11, the not shown piston rod arrangement is protected also when the cartridge assembly 20 is removed as it is difficult for a user to obtain physical contact with the piston rod arrangement which 15 moves primarily inside the tubular extension 11. The longitudinal extension 11 is further provided with a number of openings or windows 12 through which the user can inspect the content of the liquid drug when the cartridge assembly 20 is mounted and the position of the piston rod.

[0120] 20 As best seen in figure 2A, the housing structure 10 is provided with a bayonet track 14 made up from an axial opening 14a and a peripheral track 14b which both cooperate with bayonet protrusions provided on an inner surface of the cartridge assembly 20 to thereby lock the cartridge assembly 20 to the housing structure 10. Preferably, two such bayonet tracks 14 are provided.

[0121] 25

[0122] Internally, the longitudinal extension 11 of the housing structure 10 is provided with a number of longitudinal rails upon which the cartridge 40 is guided when the cartridge assembly 20 is axially mounted onto the hosing structure 10.

[0123] 30 On the inner surface of the longitudinal extension 11 a number of inwardly pointing protrusions 13 are provided which engages with the protective cap 30 when such is mounted onto the housing structure 10 as will be explained.

[0124] The housing structure 10 further accommodates a cartridge assembly 20 which slides over the 35 longitudinal extension 11 and over a part of the main part of the housing structure 10. For this240054W001

[0125] 13

[0126] purpose, the main part of the housing structure 10 is provided with a recessed area having a distally facing annular surface 15 which abuts the proximal end of the cartridge assembly 20 when such is mounted.

[0127] 5 Cartridge Assembly

[0128] The cartridge assembly 20 is disclosed in the figures 3A-C and comprises a cartridge holder part 25 and a cartridge 40 which are permanently and irreversibly connected together to form one unitary unit hereafter referred to as the cartridge assembly 20.

[0129] As disclosed in figure 3A, the cartridge holder part 25 which is moulded from a suitable polymer, is provided with one or more windows or openings 23 allowing the user to inspect the liquid drug contained in the cartridge 40. Distally, the cartridge holder part 25 is provided with a needle interface 22 for securing a double pointed pen-needle to the cartridge assembly 20. 15

[0130] On the outer surface, a number of outwardly pointing protrusions 24 are provided which are able to engage and secure the protective cap 30 on the cartridge assembly 20 as will be explained.

[0131] 20 The cartridge 40 is preferably made from glass and is distally closed by a pierceable septum 41 secured by a metal wrap. Proximally, the cartridge 40 is locked by a movable plunger 42 which can be moved in the distal direction by a piston rod 16 of the dose setting- and expelling mechanism.

[0132] 25 The compartment between the pieceable septum 41 and the movable plunger 42 contains the liquid drug which can be pressed out through a connected double pointed pen-needle when the movable plunger 42 is moved distally to thereby decrease the volume of the compartment.

[0133] The metal wrap is folded around a neck part 43 during filling of the cartridge 40 which usually 30 takes place at a sterile filling facility.

[0134] The cartridge holder part 25 is proximally formed with a skirt 26 which fits over the housing structure 10. Distally the cartridge holder part 25 is provided with a support flange 27 which supports the cartridge 40 and a number of fixing arms or knobs which grips behind the neck 35 part 43 of the cartridge 40 to irreversibly lock the cartridge 40 to the cartridge holder part 25.240054W001

[0135] 14

[0136] On the inner surface, the cartridge part 25 is provided with one or more bayonet protrusions 28 which operates in the bayonet track 14 of the housing structure 10 to secure the cartridge assembly 20 to the housing structure 10. When the cartridge assembly 20 is attached to the 5 housing structure 10, the proximal end 29 of the cartridge assembly 20 abut the annular surface 15 on the housing structure 10 as will be explained.

[0137] The skirt 26 can in one example be provided with a label carrying information regarding the liquid drug contained in the cartridge 40 of the cartridge part 25. This has the benefit that the user can visually inspect the information on the label even when the protective cap 30 is mounted on the cartridge part 25 of the cartridge assembly 20 hence the user do not need to remove the protective cap 30 in order to read the information on the label.

[0138] Protective Cap

[0139] 15

[0140] The protective cap 30 is shown in different views in the figures 4A-C. As seen in figure 4B and in figure 4C, the protective cap 30 is internally provided with a first coupling means in form of a number of outwardly pointing grooves 31 carried on a number of axial support arms 33 moulded at the distal end-surface 34 of the protective cap 30. At the proximal end of protective 20 cap 30, at a radially inwards facing surface thereof, the protective cap 30 is further provided with a recessed track 32 which constitutes the second coupling means.

[0141] The distal end-surface 34 of the protective cap 30 is further provided with a needle protection feature 35 in form of an axial circular portion as best seen in figure 4C. If the user tries to secure the protective cap 30 to the cartridge assembly 20 while a double pointed pen-needle is mounted on the needle interface 22, the axial support arms 33 will contact the pen-needle which makes it impossible for the recessed track 32 to reach the outwardly pointing protrusion 24 which will thus inform the user that the pen-needle should be removed before the protective cap 30 is mounted over the needle interface 22. At the same time the needle protection feature 30 35 protects the tip of the pen-needle from being damaged by the protective cap 30. The dimensions of the needle protection feature 35 can also be dimensioned such that this feature abuts the pen-needle and prevents the protective cap 30 from being properly attached to the cartridge assembly 20.240054W001

[0142] 15

[0143] When the protective cap 30 is mounted on the housing structure 10, the outwardly pointing grooves 31 are free to engage with the inwardly pointing protrusions 13 inside the housing structure 10 as the axial arms 33 enters into the longitudinal opening of the longitudinal extension 11 on the housing structure 10.

[0144] 5

[0145] Protective Cap on Housing Structure

[0146] Figure 5A discloses the protective cap 30 mounted on the housing structure 10 without the cartridge assembly 20 mounted. This would typically be the way the re-usable injection device is delivered to the end user, usually placed in a box made from a polymer or from a cardboard material.

[0147] The details of the releasable connection between the protective cap 30 and the housing structure 10 is shown in detail in figure 5B wherein further details relating to the dose selection- 15 and expelling mechanism is left out. Details regarding the dose selection- and expelling mechanism can be found in PCT patent application No. PCT / EP2025 / 080742 which is hereby incorporated by reference.

[0148] The outwardly pointing grooves 31 carried by the axial support arms 33 are clicked into 20 engagement with the outwardly pointing protrusions 13 inside the longitudinal extension 11 of the housing structure 10 when the protective cap 30 is mounted onto the housing structure 10 without the cartridge assembly 20 being attached.

[0149] Cartridge Assembly on Housing Structure

[0150] 25

[0151] Figure 6A shows the cartridge assembly 20 mounted onto the housing structure 10 prior to mounting the protective cap 30.

[0152] As best seen in figure 6B, the skirt 26 of the cartridge assembly 20 covers, at least partly, the 30 main part of the housing structure 10 and the outer part of the cartridge assembly 20 slides on the outside of the longitudinal extension 11 of the housing structure 10 while the cartridge 40 itself slides inside the longitudinal extension 11. The outwardly pointing protrusions 24 provided on the outer surface of the cartridge assembly 20 engages with the recessed track 32 when the protective cap 30 is mounted onto the cartridge assembly 20.

[0153] 35240054W001

[0154] 16

[0155] Protective Cap on Cartridge Assembly

[0156] When the cartridge assembly 20 is mounted onto the housing structure 10 as disclosed in figure 7A, the proximal end 29 of the cartridge assembly abuts the annular surface 15 of the 5 housing structure 10 and the protective cap 20 can be mounted onto the cartridge assembly 20. For this purpose, the outwardly pointing protrusions 24 provided on the cartridge assembly 20 engages the recessed track 32 inside the protective cap 20 such that the protective cap 20 remains seated on the cartridge assembly 20 but can be released by the user pulling off the protective cap 30.

[0157] As best seen in figure 7B, the axial arms 33 are physically shaped such that they can slide on the outside of the needle interface 22 and surround the needle interface 22 when no penneedle is mounted om the needle interface 22. Once a pen-needle is mounted, the axial arms 33 will abut the pen-needle when the user attempts to mount the protective cap 30 onto the 15 cartridge assembly 20 whereby the recessed track 32 inside the protective cap 30 cannot reach the outwardly pointing protrusions 24 on the cartridge assembly 20 with the result that the protective cap cannot be properly fitted onto the cartridge assembly. This provides information to the user that a pen-needle is mounted and should be removed before the protective cap 30 can be correctly mounted on the cartridge assembly 20.

[0158] 20

[0159] Second Embodiment

[0160] This second embodiment comprises the same mechanical parts as the first embodiment. The same mechanical details are in this second embodiment numbered with the same numbers as 25 used in the first embodiment, however, with a “1” in front of the number such that e.g. the protective cap is numbered with “30” in the first embodiment and numbered “130” in the second embodiment.

[0161] Figure 8 disclose an example of the protective cap 130 according to a second embodiment of 30 the invention. This protective cap 130 is on the inner surface provided with two separate and axially displaced coupling means which are, namely, a first coupling means embodied as a plurality of inwardly pointing protrusions 131 which are able to engage with the housing structure 110 and a second coupling means in form of a recessed track 132 which is able to engage with the cartridge holder 125.

[0162] 35240054W001

[0163] 17

[0164] Figure 9 shows the housing structure 110 according to the second embodiment. This housing structure 110 is similar to the housing structure of the first embodiment, however, the first engaging means for engaging the protective cap 130 has been moved to the middle part of the injection device and is formed as a groove 113 encircling the diameter of the injection device.

[0165] 5

[0166] Figure 10 discloses the cartridge holder 125 which in the second embodiment is shown without the cartridge mounted. However, in a situation of use, the cartridge is irreversibly secured to the cartridge holder part 125 to make up the cartridge assembly. The cartridge holder part 125 in the second embodiment is identical to the cartridge holder part of the first embodiment and is on the outer surface provided with one or more outwardly pointing protrusions 124 to engage with the protective cap 130.

[0167] Figure 11 shows the protective cap 130 mounted directly on the housing structure 110 without the cartridge holder 125 being mounted.

[0168] 15

[0169] The inwardly pointing protrusions 131 on the protective cap 130 engages the groove 113 on the housing structure 110 such that the protective cap 130 is being releasably fixated to the housing structure 110.

[0170] 20 Figure 12 discloses the protective cap 130 mounted on the cartridge holder 125.

[0171] The cartridge holder 125 is first attached to the housing structure 110 using the bayonet coupling as previously explained. Whenever the user hereafter needs to connect the protective cap 130 after an injection, the protective cap 130 is slided onto the cartridge holder 125 until the recessed track 132 provided on the inner surface of the protective cap 130 engages with the outwardly pointing protrusion 124 provided on the outer surface of the cartridge holder part 125.

[0172] Some preferred embodiments have been shown in the foregoing, but it should be stressed that 30 the invention is not limited to these but may be embodied in other ways within the subject matter defined in the following claims.240054W001

[0173] 18

[0174] List of Parts:

[0175]

Claims

240054W00119CLAIMS:

1. A re-usable injection device with a releasably mountable protective cap, which re-usable injection device comprises:5 a housing structure (10, 110) containing a dose selection- and expelling mechanism,a cartridge assembly (20) irreversibly securing a cartridge (40), the cartridge assembly (20) being exchangeably connectable at a distal end of the housing structure (10, 110),wherein the housing structure (10, 110) is provided with first engaging means (13, 113) for releasably engaging the protective cap (30, 130) for releasably mounting the protective cap (30, 130) at the distal end of the housing structure (10, 110), andthe cartridge assembly (20) is provided with second engaging means (24, 124) for releasably 15 engaging the protective cap (30, 130) for releasably mounting the protective cap (30, 130) at a distal end of the cartridge assembly (20),characterized in that the protective cap (30 130) comprises two separate coupling means:20 a first coupling means (31, 131) adapted to engage the first engaging means (13, 113) on the housing structure (10, 110) when the cartridge assembly (20) is disconnected from the housing structure (10, 110), anda second coupling means (32, 132) adapted to engage the second engaging means (24, 124) on the cartridge assembly (20) when the cartridge assembly (20) is connected to the housing structure (10, 110).

2. A re-usable injection device according to claim 1, wherein the first coupling means (31) are provided in the distal part of the protective cap (30).

303. A re-usable injection device according to claim 2, wherein the first coupling means (31) is a number of outwardly pointing grooves (31) preferably carried on a number of axial arms (33) extending from a distal end-surface (34) of the protective cap (30).240054W001204. A re-usable injection device according to claim 1, wherein the first coupling means (131) are provided in the proximal part of the protective cap (130).

5. A re-usable injection device according to claim 4, wherein the first coupling means (131) is 5 a number of protrusions (131) arranged on a radially inwards facing surface of protective cap (130).

6. A re-usable injection device according to any of the previous claims, wherein the second coupling means (32, 132) are provided in the proximal part of the protective cap (30, 130).

7. A re-usable injection device according to any of the previous claims, wherein the second coupling means (32, 132) is a recessed track (32, 132).

8. A re-usable injection device according to any of the previous claims, wherein the physical 15 length of the injection device with the protective cap (30) mounted is approximately the same with the cartridge assembly (20) attached as without the cartridge assembly (20) attached.

9. A re-usable injection device according to any of the previous claims, wherein the cartridge assembly (20) comprises a movable plunger (42), and wherein the dose selection- and 20 expelling mechanism comprises a piston rod (16) configured for movement from a proximal first position towards a distal second position so as to move the plunger (42) in the distal direction.

10. A re-usable injection device according to claim 9, wherein the housing structure (10, 110) 25 defines a proximal main body and a longitudinal extension (11) fixedly attached to or being integrally formed with the main body, wherein the longitudinal extension (11) is formed to encircle the piston rod (16) and axially overlap the piston rod (16) when the piston rod assumes the distal second position.30 11. A protective cap adapted to be releasably mountable on a re-usable injection device, the re-usable injection device comprising:a housing structure (10, 110) containing a dose selection- and expelling mechanism,a cartridge assembly (20) irreversibly securing a cartridge (40) and being exchangeably 35 connectable to the housing structure (10, 110),240054W00121wherein the housing structure (10, 110) is provided with first engaging means (13, 113) for releasably engaging the protective cap (30, 130), and5the cartridge assembly (20, 120) is provided with second engaging means (24, 124) for releasably engaging the protective cap (30, 130),characterized in that the protective cap (30 130) comprises two separate coupling means:a first coupling means (31, 131) adapted to engage the first engaging means (13, 113) on the housing structure (10, 110) when the cartridge assembly (20) is disconnected the housing structure (10, 110), and15 a second coupling means (32, 132) adapted to engage the second engaging means (24, 124) on the cartridge assembly (20, 120) when the cartridge assembly (20) is connected to the housing structure (10, 110).20 12. A protective cap according to claim 11 , wherein the first coupling means (31) are provided in the distal part of the protective cap (30).

13. A re-usable injection device according to claim 11, wherein the first coupling means (131) are provided in the proximal part of the protective cap (30).2514. A protective cap according to claims 11, 12 or 13, wherein the second coupling means (32, 132) are provided in the proximal part of the protective cap (30, 130).

Images