Injection device with fill level indicator

Abstract

The present disclosure relates to an injection device for setting and injecting a dose of a medicament, the injection device comprising: an elongated housing (90) extending in a longitudinal direction and configured to accommodate a cartridge (6); a first member (30) movably arranged inside the elongated housing (90) for setting the dose; and a second member (10); a piston rod (20) configured to be advanced in a longitudinal distal direction (2) and operable to apply a distally directed pressure to a bung (7) of the cartridge (6) for expelling the dose, wherein during one of the setting of the dose and the expelling of the dose, the first member (30) is rotatable relative to the second member (10), and wherein during the other of the setting of the dose and the expelling of the dose, the first member (30) is rotatable relative to the second member (10). a filling level indicator (35; 135) which is threadedly engaged with one of the first member (30) and the second member (10), and wherein the filling level indicator (35; 135) is rotationally locked and longitudinally slidably engaged with the other of the first member (30) and the second member (10), wherein the filling level indicator (35; 135) is movable in the longitudinal direction relative to the first member (30) and / or relative to the second member (10) at least from a starting position (100) to an end position (102), and wherein when the filling level indicator (35; 135) is in the starting position (100), the filling level indicator (35; 135) is visible from the outside of the housing (90).

Description

Technical Field

[0001] The present disclosure relates to the field of injection devices, and more particularly to handheld injection devices such as pen-type injectors. Background Art

[0002] Drug delivery devices for setting and dispensing single or multiple doses of liquid medicaments are well known in the art. Generally, such devices have a substantially similar purpose to ordinary syringes.

[0003] Drug delivery devices, such as pen-type injectors, must meet many user-specific requirements. For example, in the case of a patient suffering from a chronic disease such as diabetes, the patient may be physically weak and may also be visually impaired. Therefore, suitable drug delivery devices, especially intended for home medication, need to be robust in construction and should be easy to use. In addition, the manipulation and general handling of the device and its components should be clear and easy to understand. Such injection devices should provide for the setting and subsequent distribution of medicament doses of variable size. In addition, the dose setting and dose distribution procedures must be easy to operate and must be clear.

[0004] Typically, such devices include a housing or a specific cartridge holder adapted to receive a cartridge at least partially filled with a medicament to be dispensed. The device further includes a drive mechanism, which typically has a displaceable piston rod to operably engage with a bung or piston of the cartridge. By means of the drive mechanism and its piston rod, the bung or piston of the cartridge can be displaced in a distal or dispensing direction, and thus a predefined amount of medicament can be expelled via a piercing assembly (e.g., in the form of an injection needle), which is releasably connected to a distal section of the housing of the drug delivery device.

[0005] The medicament to be distributed by the drug delivery device can be provided and contained in a multi-dose cartridge. Such cartridges typically include a glass barrel that is sealed in the distal direction by means of a pierceable seal and further sealed in the proximal direction by a stopper. For a reusable drug delivery device, an empty cartridge can be replaced with a new cartridge. In contrast, a disposable type of drug delivery device will be completely discarded when the medicament in the cartridge has been distributed or used up.

[0006] For some drug delivery devices, such as pen-type injection devices, the user must set doses of equal or variable sizes by rotating the dose dial in a clockwise or dose-increasing direction relative to the body or housing of the injection device. In order to inject and expel a dose of liquid medicament, the user must depress a trigger or dose button in a distal direction and thus toward the body or housing of the injection device. Typically, the user applies distally directed pressure on the dose button (which is located at the proximal end of the dose dial and dose dial sleeve) with his thumb while holding the housing of the injection device with the remaining fingers of the same hand.

[0007] An injection device of the pen-type injector type disclosed, for example, in WO 2004 / 078241 A1 comprises a final dose limiting mechanism. The final dose limiting mechanism may comprise a final dose limiter configured to prevent setting a dose exceeding the amount of medicament in the cartridge. To this end, a drive sleeve of the drive mechanism may be provided with a first flange and a second flange, with an intermediate thread between the first flange and the second flange. A nut may be arranged between the first flange and the second flange and keyed to the housing by a spline device.

[0008] Such a final dose stop limiting mechanism effectively interrupts the dose setting procedure if the user intends to set a dose that will exceed the residual amount of medicament provided in the cartridge.

[0009] Handheld injection devices (such as injection pens) typically include a transparent cartridge holder that is configured to receive and / or hold a cartridge filled with a medicament. This allows visual inspection of the medicament located inside the cartridge. In addition, when the cartridge contained inside the cartridge holder is also transparent or translucent, the transparent cartridge holder also enables visual inspection of the medicament.

[0010] It may be difficult for a patient or person intending to set a dose of a predetermined size to estimate or accurately determine whether the amount of medicament provided in the cartridge is large enough or sufficient to set the desired dose. It may be difficult to visually determine or check the fill level of the cartridge. In addition, cartridges that may be made of a vitreous material typically include a tubular shape that inherently provides scattering and / or deflection of light, thus making it difficult to accurately determine the amount of medicament inside the cartridge.

[0011] In view of the above, it is desirable to provide an injection device having a fill level indicator operable to visually indicate to a person or patient the residual amount or remaining fill volume of a cartridge disposed inside the injection device. It is desirable to have an accurate, robust and reliable fill level indicator that visually indicates the actual fill level of the cartridge before a user begins a dose setting procedure with the injection device. It is also desirable to have a fluid level indicator operable to visually indicate the future fluid level of the cartridge that the cartridge will have after the currently set dose has been dispensed or expelled from the cartridge. It is a particular object to enhance patient safety and overall handling and overall acceptance of handheld injection devices. Summary of the invention

[0012] In one aspect, the present disclosure relates to an injection device for setting and discharging a dose of a medicament. The injection device comprises an elongated housing, e.g., tubular, extending in a longitudinal direction. The elongated housing is configured to accommodate a cartridge. The cartridge preferably comprises a barrel filled with the medicament and sealed in a proximal longitudinal direction by a stopper. The stopper is preferably displaceable relative to the barrel for discharging the medicament.

[0013] The injection device further comprises a first member movably arranged within the elongated housing for setting a dose of the medicament. The injection device further comprises a second member. The second member is a separate member and is distinguishable from the first member.

[0014] The injection device further comprises a piston rod configured to be advanced in a longitudinal distal direction. The piston rod is operable to apply a distally directed pressure to the bung of the cartridge for expelling a dose. Typically, the piston rod is driven by a drive mechanism of the injection device in order to expel a previously set dose of medicament and during the expelling of the previously set dose of medicament.

[0015] During one of setting a dose and expelling a dose, the first member is rotatable relative to the second member. During the other of setting a dose and expelling a dose, the first member is rotationally locked to the second member. The first member and the second member may engage in a longitudinal direction or in an axial direction. The first member may be immobile and / or positionally locked to the second member with respect to the longitudinal direction or the axial direction.

[0016] For some examples, during and / or for dose setting, only one of the first and second members may be movable, while the other of the first and second members is stationary relative to the housing. During and / or for dose expulsion, the first and second members are stationary relative to each other. Here, both the first and second members may be stationary relative to the housing, or both the first and second members may undergo a joint or combined movement relative to the housing.

[0017] For some other examples, during and / or for dose setting, the first and second members are immobile relative to each other. Here, both the first and second members may be immobile relative to the housing, or both the first and second members may undergo a joint or combined movement relative to the housing. Then, for and / or during dose expulsion, at least one of the first and second members will be movable relative to the other of the first and second members.

[0018] The injection device further comprises a filling level indicator threadedly engaged with one of the first member and the second member. The filling level indicator is rotationally locked and longitudinally slidably engaged with the other of the first member and the second member. The filling level indicator may be threadedly engaged with the first member, and the filling level indicator may be in a so-called splined engagement with the second member. Rotation of the first member relative to the second member then causes a longitudinal displacement of the filling level indicator relative to the first member and the second member.

[0019] The filling level indicator can be moved in the longitudinal direction relative to the first component and / or relative to the second component at least from a starting position to an end position. When the first component rotates relative to the second component, the filling level indicator moves relative to the first component and / or relative to the second component in the longitudinal direction towards the end position. Typically, the starting position and the end position are oppositely positioned extreme positions of the filling level indicator.

[0020] In particular, when the first component is rotated relative to the second component along a first direction (for example, in a dose increasing direction during dose setting or in a dose decreasing direction during dose expulsion), the fill level indicator moves in a longitudinal direction towards the end position relative to the first component and / or relative to the second component.

[0021] For some examples, the fill level indicator moves in a longitudinal direction towards the starting position relative to the first member and / or relative to the second member when the first member is rotated relative to the second member in a second direction (e.g., in a dose decrementing direction during a dose setting process, i.e., when an already set dose is too large and wherein the previously set dose is subject to correction before dispensing or expelling the dose).

[0022] When the fill level indicator is in the starting position, the fill level indicator is visible from the outside of the housing.

[0023] Typically, the longitudinal position of the fill level indicator relative to at least one of the first and second members is directly related to the longitudinal position of the piston rod relative to the elongated housing. When the fill level indicator is in the starting position, the piston rod is in an initial position that typically coincides with the proximal position. When the fill level indicator is in the end position, the piston rod is in a final or end position that typically coincides with the distal position. For examples in which the first member is rotatable relative to the second member only during and / or for dose setting, the instantaneous longitudinal position of the fill level indicator indicates the longitudinal position in which the piston rod will be after dispensing or expelling of the actually set dose. For those examples in which the first member is rotatable relative to the second member only during and / or for dose expulsion, the instantaneous longitudinal position of the fill level indicator relative to at least one of the first and second members directly and immediately indicates the longitudinal position of the piston rod relative to the housing or cartridge.

[0024] In any case, the fill level indicator provides a visually perceptible indication of the instantaneous or future longitudinal position of the piston rod relative to the housing of the injection device. Since the piston rod is in abutment and remains in abutment with the bung of the cartridge during repeated dose setting and dose expelling procedures, the longitudinal position of the piston rod directly indicates the position of the bung relative to the barrel of the cartridge and therefore directly indicates the amount of medicament located in the cartridge.

[0025] By making the fill level indicator visible from outside the housing when arranged or in the starting position, an indication is provided to the user that the cartridge has not been used before and that all medicament initially provided in the cartridge is still inside the cartridge and is therefore still available for dose expulsion. Thus, when the fill level indicator is in the starting position, this is a clear and unambiguous indication to the user or patient of the injection device that the injection device has not been used before to expel a dose.

[0026] Providing a fill level indicator engaged with the first member and the second member and visible from outside the housing enables providing visual feedback to a user or patient using the injection device that the cartridge is fully filled and the injection device is in an initial configuration or unused state. In addition to an optional pre-injection or priming step, when in the starting position, the fill level indicator indicates that the initial fill volume of the cartridge is still available.

[0027] In general, the fill level indicator can be arranged at any suitable part of the housing of the injection device. Typically, the fill level indicator can be arranged at or near the distal end of the proximal housing component (also represented as the body of the housing). The body of the housing is typically configured to receive or accommodate a drive mechanism of the injection device. The housing further includes a cartridge holder, which is configured to receive or accommodate a cartridge filled with a medicament. In a typical configuration, the distal end of the cartridge holder is configured to hold a detachable injection needle. The distal end of the cartridge holder forms or constitutes the distal end of the injection device. The proximal end of the cartridge holder can be interconnected or fastened to the distal end of the body.

[0028] At the proximal end of the body, at least one of a dose dial and an injection button may be provided, the dose dial and the injection button being operable to set and / or dispense or expel, for example, a dose of variable size. A fill level indicator may be located at or near a distal end of the body, wherein the body forms or constitutes a proximal part of a housing of the injection device. The fill level indicator may be positioned longitudinally offset from a protective cap typically covering the cartridge holder or at least the distal end of the cartridge holder. By providing the fill level indicator on the proximal housing part, the instantaneous fill level of the cartridge, which typically corresponds to the instantaneous longitudinal or axial position of the piston rod relative to the housing, can be permanently assessed from outside the housing without having to disassemble or remove the protective cap from the injection device.

[0029] Typically, and when the fill level indicator is in the starting position, the piston rod is in a proximal configuration or proximal position. In the proximal configuration or proximal position, the piston rod may be axially adjacent to the bung of the cartridge, or the piston rod may be positioned close to the bung of the cartridge with a well-defined gap therebetween. In the latter case, the injection device must undergo a pre-filling procedure before the first injection can be made. During the pre-filling procedure, the piston rod is advanced in the distal direction until it engages with the bung. This initial but very small distally directed movement of the piston rod may only optionally be reflected in a corresponding modification of the position of the fill level indicator relative to the housing. Moreover, the fill level indicator may have reached the starting position when the pre-filling procedure has been completed.

[0030] Since the injection device is repeatedly used to set and expel doses of medicament, the piston rod is continuously advanced in the longitudinal distal direction. The more the piston rod is advanced or moved in the longitudinal distal direction, the more the fill level indicator is advanced towards the end position. When the piston rod has reached the distal position inside the injection device, the fill level indicator also reaches the end position relative to the housing.

[0031] Typically, the starting position of the fill level indicator is a longitudinal starting position. The end position of the fill level indicator is a longitudinal end position relative to at least one of the first member and the second member. During the dose setting process or during the dose expelling process, the fill level indicator moves toward the end position. For some examples, the fill level indicator can slide relative to the second member in the longitudinal direction. The second member can provide a sliding track for the fill level indicator. During repeated dose setting procedures or during repeated dose expelling procedures, the fill level indicator can slide continuously from the starting position toward the end position along the sliding track as provided by the housing. Typically, the starting position is one of the proximal stop position and the distal stop position, and the end position is the other of the proximal stop position and the distal stop position.

[0032] According to another example, when the fill level indicator is in the end position, the fill level indicator is visible from the outside of the housing. In this way, the fill level indicator is operable to visually indicate to the user or patient that the cartridge is substantially empty or nearly empty and that the residual amount of medicament remaining in the cartridge is too little or will be too little, or insufficient to set and / or expel any additional dose of medicament.

[0033] In this configuration, and when the fill level indicator has reached an end position relative to the housing, this is a clear and visual indication to the user or patient that the injection device can no longer be used to set and expel doses of medicament.

[0034] According to another example, the fill level indicator is visible from the outside of the housing in any position between the starting position and the end position of the fill level indicator. In this way, the fill level indicator is operable to visually indicate the amount of medicament provided in the cartridge. Typically, the longitudinal displacement of the fill level indicator during dose setting or during dose expulsion and towards the end position is proportional to the distally directed advancement movement of the piston rod during the dose expulsion or dose dispensing procedure. In this way, and when the fill level indicator is, for example, located halfway between the starting position and the end position, this is an immediate indication to the user or patient that half of the initial fill volume of the medicament is still located inside the cartridge.

[0035] The proportional mechanical coupling between the fill level indicator, the first member and the second member is particularly beneficial for providing a user with linear visual feedback regarding the instantaneous fill level of a cartridge located inside the injection device.

[0036] Overall, and by making the fill level indicator visible from outside the housing in any position between the start position and the end position, a fairly direct tracking of the cumulative size of doses that have been set and / or dispensed or expelled with the injection device is provided.

[0037] According to another example, the first member and the second member include a first stopper and a second stopper. Here, one of the first member and the second member may include both the first stopper and the second stopper. Alternatively, one of the first member and the second member includes the first stopper and the other of the first member and the second member includes the second stopper.

[0038] The first stop and the second stop are separated from each other in the longitudinal direction. Typically, the first stop defines a starting position of the fill level indicator. The second stop typically defines an end position of the fill level indicator. When in the starting position, the fill level indicator may engage with the first stop. In the starting position, the fill level indicator may abut against the first stop. When in the starting position, the fill level indicator may be in at least one of axial or tangential abutment with the first stop.

[0039] In a further example, the fill level indicator engages a second stop when reaching or being in the end position. Here, when the fill level indicator engages or abuts the second stop, the fill level indicator is operable to prevent further movement of the first member relative to the second member at least in one direction (e.g., the first direction of movement). Here, the second stop forms or provides a final dose stop that effectively prevents setting a dose that will exceed the residual amount of medicament provided in the cartridge.

[0040] Thus, the second stop of the first member or the second member defines an end position of the fill level indicator relative to the housing.When in the end position, the fill level indicator is typically in at least one of an axial or tangential engagement with the second stop.

[0041] In this way, and when the first member is subjected to rotational movement relative to the second member, the filling level indicator begins to move according to the spiral path relative to the one of the first member and the second member with which the filling level indicator is threadedly engaged. At the same time, the filling level indicator begins to slide along the sliding track provided by the other of the first member and the second member. When reaching one of the starting position and the end position or being in one of the starting position and the end position, the filling level indicator engages with the corresponding stop. When reaching the starting position, the filling level indicator engages with (e.g., abuts) the first stop. When reaching the end position, the filling level indicator will engage (e.g., abut) the second stop.

[0042] At least one of the first stop and the second stop will be operable to further displace the fill level indicator beyond the first stop or the second stop, respectively. Since the fill level indicator is rotationally locked to one of the first member and the second member, a circumferential, tangential or longitudinal abutment between the fill level indicator and one of the first stop and the second stop of one of the first member and the second member immediately blocks any further rotation of the first member relative to the second member, e.g. in a first direction, which may be a dose incrementing direction when the first member and the second member are subjected to relative movement only during dose setting.

[0043] In this way, the fill level indicator is not only operable to visualize the instantaneous position of the piston rod, but also to prevent setting of a dose that would exceed the amount of medicament provided in the cartridge.

[0044] For some examples, the second component is a housing component (e.g., a body of the elongated housing), and the first component is one of a dose setting component and a dose expelling component, wherein the dose setting component undergoes rotational movement relative to the housing component or the body only during dose setting, and wherein the dose expelling component undergoes rotational movement relative to the housing component or the body only during dose expelling.

[0045] For some examples, the first member comprises a sleeve or tubular shape. Typically, and when the first member is implemented as a dose setting member or a dose expelling member, it is arranged inside the second member, which may include a tubular hollow body. The first member and the second member may be coaxially arranged in a nested or coiled manner. The outer surface of the first member may engage with the inner part of the filling level indicator. The outwardly facing portion of the filling level indicator is then typically engaged with the inwardly facing portion of the second member, and thus engaged with the body.

[0046] When the first member is threadedly engaged with the fill level indicator, the second member is splined with the fill level indicator. During dose setting, when the first member is rotated relative to the second member in a first direction, the first member can rotate relative to the second member, thereby causing a longitudinal movement of the fill level indicator towards the end position. During dose expulsion, the first member is non-rotatably locked to the second member, for example by means of an adapter. Then, and during dose expulsion, the first member can be stationary relative to the housing or body, or it can be subjected to a non-rotating pure longitudinal sliding movement. In the latter case, both the fill level indicator and the first member can be subjected to a common and / or combined sliding movement relative to the housing.

[0047] According to another example, the housing of the injection device further comprises an elongated aperture extending in the longitudinal direction. In addition, the filling level indicator comprises an indicating portion. The indicating portion is visible through the elongated aperture of the housing. The scale typically extends along a sliding track or displacement path of the filling level indicator starting from the starting position and ending at the end position. For some examples, the elongated aperture is directly arranged in the first member.

[0048] For a typical example, the elongation of the orifice is as long as the distance from the starting position to the ending position of the fill level indicator. The total longitudinal elongation of the orifice may indicate and may directly correspond to the maximum or initial fill volume of the cartridge of the injection device. The longitudinal position of the fill level indicator and / or the longitudinal position of the indicating portion of the fill level indicator relative to the oppositely positioned longitudinal ends of the elongated orifice directly indicates the amount of medicament provided in the cartridge relative to the initial or total fill volume of the cartridge.

[0049] For another example, the elongated aperture of the housing includes a first longitudinal end and further includes an oppositely positioned second longitudinal end. When the fill level indicator is in the starting position, the indicating portion of the fill level indicator may be positioned proximate to the first longitudinal end of the elongated aperture or may abut (e.g., longitudinally abut and thus axially abut) the first longitudinal end of the elongated aperture. When the fill level indicator is in the end position, the corresponding indicating portion of the fill level indicator may be positioned proximate to the second longitudinal end of the elongated aperture. It may overlap with the second longitudinal end and / or it may abut (e.g., axially abut) the second longitudinal end of the aperture.

[0050] In this way, at least the second longitudinal end of the aperture may provide a stop to engage with the longitudinally displaceable fill level indicator. When the fill level indicator reaches the second end position, it may axially engage (i.e. it may axially abut) the second longitudinal end of the elongated aperture. In this way, the second longitudinal end of the elongated aperture may serve as a second stop, as described above. It may provide a final dose stop, which is configured to prevent any further longitudinal movement of the fill level indicator beyond the end position relative to the housing.

[0051] According to another example, the elongated orifice is covered or closed by a transparent window. The elongated orifice may be completely closed or filled with the transparent window. In this way, the interior of the housing of the injection device may be effectively protected from the ingress of moisture and / or particles. Furthermore, manual manipulation of the filling level indicator may be effectively prevented by the transparent window. The transparent window covering the elongated orifice may completely cover and / or surround the filling level indicator located below.

[0052] According to a further example, the housing comprises an elongated orifice extending in the longitudinal direction of the elongated housing. Here and in contrast to the previously described examples, at least an indicating portion of the fill level indicator is located outside the housing, while the remaining portion or base portion of the fill level indicator is located inside the housing, in particular in a region between the interior of the elongated housing and the exterior of one of the first member or the second member.

[0053] By arranging at least a dedicated portion of the fill level indicator outside the housing, the readability and size of the fill level indicator, in particular the readability and size of the indicating portion of the fill level indicator, can be increased compared to an example in which the fill level indicator is completely located inside the housing. In addition, arranging at least a portion of the fill level indicator on or outside the housing can even provide a user with tactile feedback about the instantaneous fill level of the cartridge. The position of the indicating portion of the fill level indicator can be tactilely sensed, which can become palpable. In addition, by arranging at least the indicating portion of the fill level indicator on or outside the housing, the indicating portion operable to indicate the instantaneous longitudinal position of the piston rod relative to the housing can be spatially separated from the base portion of the fill level indicator at least with respect to one of the longitudinal or circumferential directions. The base portion mechanically engages both the first member and, for example, the inner side wall portion of the second member, for example, of the elongated housing.

[0054] According to another example, the filling level indicator comprises an L-shaped rod, the L-shaped rod comprising an indicating portion and further comprising a bridging portion. Here, the bridging portion extends through the orifice and is connected to or connectable to a base portion of the filling level indicator. The base portion of the filling level indicator is mechanically engaged with both the first member and the second member. The bridging portion extending through the orifice comprises a radial extension, which is greater than the thickness of the side wall of the elongated housing. In this way, the L-shaped rod of the filling level indicator and in particular the indicating portion can include one of an annular circumferentially extending structure and a longitudinally extending rod-shaped structure arranged outside the housing.

[0055] The L-shaped rod enables an arrangement of the fill level indicator with an elongated or longitudinally extending indicating portion (an arrangement in which at least the indicating portion of the fill level indicator is axially or longitudinally offset from a base portion of the fill level indicator). In this way, that portion of the fill level indicator which is visually perceptible from outside the housing can be located at a position which is axially and / or circumferentially offset from the first member and / or from the orifice in the housing.

[0056] In this way, the fill level can be indicated at almost any arbitrary or desired position on the outer surface of the housing of the injection device.Thus, the overall design of the injection device can be adapted and designed to meet given user requirements.

[0057] According to a further example, the injection device comprises an outer housing covering or surrounding at least a portion of the housing in the region of the fill level indicator. The outer housing comprises a transparent window overlapping at least the indicating portion of the fill level indicator. The outer housing is particularly intended for use in examples in which an aperture in the housing or inner housing of the injection device is free of a transparent window and in which a bridging portion of the fill level indicator extends through an aperture of the housing or inner housing. By means of the outer housing, the aperture of the inner housing through which the fill level indicator extends can be effectively closed or enclosed and thus protected from the ingress of particles or moisture.

[0058] According to another example, the housing of the injection device includes a cartridge holder configured to accommodate a cartridge. In this particular example, the cartridge holder is opaque. At least in terms of the visible spectrum of electromagnetic radiation (e.g., visible light), it is opaque. For other examples, the cartridge holder is at least opaque for a dedicated spectrum of electromagnetic radiation. The cartridge holder may be opaque with respect to ultraviolet radiation and / or with respect to infrared radiation.

[0059] Except the through-opening for receiving the proximal tip of the injection needle in the distal face, the cartridge holder does not have any apertures or through-openings in the side wall. In this way, the cartridge holder is configured to completely surround the cartridge and protect the cartridge from electromagnetic radiation from the outside.

[0060] Providing an opaque cartridge holder is beneficial for protecting the medicament located therein from corresponding electromagnetic radiation. In this way, the cartridge holder is used to protect the cartridge and the medicament located therein from the adverse effects caused by irradiation with one of the electromagnetic radiations in the visible spectral range, the ultraviolet spectral range and / or the infrared spectral range.

[0061] Some medicaments are quite sensitive to electromagnetic radiation. Here, an opaque and / or non-transparent cartridge holder is beneficial to protect the medicament from such harmful environmental influences.

[0062] With the fill level indicator, visual inspection of the cartridge and / or the medicament located thereon may become superfluous.Thus, the implementation of the fill level indicator enables the use of a cartridge holder that is substantially opaque with respect to at least one of infrared radiation, light in the visible spectral range and UV radiation.

[0063] According to another example, the housing comprises a scale extending along the elongated aperture of the housing. The indicating portion of the fill level indicator comprises a pointer pointing to the scale. The scale typically comprises a plurality of marks or symbols indicating the longitudinal position of the piston rod relative to the housing and thus indicating the amount of residual medicament remaining in the cartridge. The scale may comprise a plurality of marks or markings. Such marks or markings may be arranged equidistantly in the longitudinal direction along the longitudinal extension of the scale.

[0064] The scale may be provided with symbols or numbers, thus indicating the amount of medicament still available in the cartridge.

[0065] Typically, the pointer includes a tip pointing to the scale. The pointer can be provided as an additional marking on the outer surface of the indicating portion of the fill level indicator. The scale can be provided on the outside of the housing. It can be divided into a plurality of sections positioned adjacent to each other in the longitudinal direction. Each of the sections can have the characteristics of a specific configuration of the injection device. A section adjacent to the first longitudinal end of the orifice can indicate that the cartridge is almost or substantially completely filled with medicament. Another section located at the second longitudinal end of the orifice can indicate that less than a predetermined amount of medicament is located in the cartridge when the fill level indicator overlaps this particular section of the scale.

[0066] Multiple and / or adjacently located segments of the scale may be provided with different colors, thus enabling a particularly intuitive and comprehensive understanding of the instantaneous configuration of the injection device.

[0067] According to another example, the filling level indicator comprises at least one of a radial protrusion or a radial depression and a threaded section. The threaded section is an external threaded section or an internal threaded section. The threaded section is threadedly engaged with a correspondingly shaped reverse threaded section of one of the first member and the second member. At least one of the radial protrusion or radial depression of the filling level indicator is longitudinally slidably engaged with a correspondingly shaped radial depression or radial protrusion of the other of the first member and the second member. One or more corresponding depressions and one or more protrusions of one of the first member or the second member and the filling level indicator enable a longitudinally directed sliding movement of the filling level indicator relative to the corresponding first member or the second member provided with the correspondingly shaped radial depression or radial protrusion.

[0068] At least one radial recess or radial projection may be provided on the fill level indicator, which engages and / or cooperates with a correspondingly shaped radial projection or recess of one of the first and second members. A plurality of radial recesses and / or projections may be provided on the fill level indicator, which engage and / or cooperate with a corresponding number of correspondingly shaped radial projections and / or recesses of one of the first and second members. In this way, a double, triple or even quadruple sliding and rotationally locked engagement between the fill level indicator and one of the first and second members may be provided, thus resulting in a fairly robust and reliable implementation of the fill level indicator.

[0069] For one example, the filling level indicator includes an internal thread engaged with an external thread of the second member. The filling level indicator further includes a radially outwardly extending protrusion, which engages with a radially and longitudinally extending recess or groove of a corresponding shape arranged on the inner surface of the first member. In this way, and when the second member, for example, a drive sleeve of a dose setting sleeve or a drive mechanism is rotated relative to the housing, the filling level indicator slides along one or more longitudinal recesses or grooves of the first member. Here, the first member can be implemented as a tubular housing or body, for example. The first member can also be implemented as an insert rigidly attached and / or fixed to the body or housing or its interior. Here, the longitudinally extending recess or groove of the first member provides a sliding track, which extends from the starting position of the filling level indicator toward and / or until the filling level indicator relative to the end position of the first member, for example, implemented as a body or housing.

[0070] For other examples, the fill level indicator comprises an external thread engaging with a correspondingly shaped internal thread of the first member. Here, the fill level indicator comprises one of a radially inwardly extending protrusion or a corresponding recess to engage with a correspondingly shaped recess or a radially extending protrusion of the second member. The second member, for example implemented as a dose setting sleeve or a drive sleeve, may comprise one of an elongated and longitudinally extending groove that slidably engages with the radially extending protrusion of the fill level indicator. Alternatively, the fill level indicator comprises an elongated groove or an elongated radial recess that engages with a correspondingly shaped radial protrusion of the second member.

[0071] The radial protrusion is one of the protrusions extending radially outward and radially inward. The longitudinal recess is complementary in shape to the radial protrusion. When the radial protrusion extends radially outward on the fill level indicator, the elongated recess is typically provided on the inner sidewall portion of the first member or the second member. When the radial protrusion extends radially inward on the fill level indicator, the elongated recess is typically provided on the outer sidewall portion of the first member or the second member.

[0072] In either case and when the second component is subjected to a rotational movement relative to the first component, the fill level indicator is subjected to a longitudinal displacement relative to the first component in the direction towards the end position.

[0073] When in splined and thus longitudinal sliding engagement with the second member, the fill level indicator may comprise an arcuate or semicircular structure, thus representing a half nut. When the fill level indicator is in longitudinal and / or splined sliding engagement with the first member, and when the fill level indicator is in threaded engagement with the second member, the fill level indicator typically has an annular shape. Here, the second member, which is realized, for example, as a housing, a body or a housing part and comprises a longitudinally extending elongated orifice, provides a constant visual check of the longitudinal and / or axial position of the fill level indicator in the orifice of the second member and thus from outside the housing.

[0074] According to another example, during the dispensing of the dose of the medicament, when the piston rod is advanced in the longitudinal distal direction relative to the housing, the first member is rotationally locked to the housing. During the dose dispensing or dose expelling process, the first member may be immovable relative to the second member. The first member may be locked to the second member at least with respect to the rotational movement. The first member may also be locked to the second member with respect to the axial or longitudinal movement. The first member may be permanently locked in the axial direction relative to the second member (i.e., during the dose setting and dose dispensing or dose expelling process).

[0075] In another example, the fill level indicator is displaceable only and exclusively relative to at least one of the first member and the second member during dose setting. During and / or for dose setting, the fill level indicator may be displaced relative to both the first member and the second member. During dose setting, the fill level indicator may be subjected to a sliding movement relative to the second member. During dose setting, the fill level indicator may be subjected to a rotational or spiral movement relative to the first member. When the dose is set, the fill level indicator and the first member may be rotated relative to each other. They may remain non-rotatable relative to each other, or may be rotationally locked to each other when the dose is expelled. In this way, and when the fill level indicator moves along the sliding track as defined by the first member during dose setting, the instantaneous position of the fill level indicator relative to the first member and / or relative to its elongated orifice is indicative and / or represents a summary dose previously set by the injection device.

[0076] When the fill level indicator is in the end position, the summed set dose that has been previously set by the injection device is typically equal to the initial dose of medicament inside the cartridge.

[0077] The injection device typically includes a switchable coupling selectively engaging with the first member and the second member. Typically, and when the switchable coupling is in one of the dose setting state and the dose expelling state, the first member is rotatable relative to the second member. When the coupling is switched to the other of the dose setting state and the dose expelling state, the first member is / becomes rotationally locked to the second member. For some examples, when the coupling is in the dose setting state, the first member is rotatable relative to the second member. When the coupling is in the dose expelling state, the first member is rotationally locked to the second member.

[0078] For some other examples, when the adapter is in the dose expelling state, the first member is rotatable relative to the second member. When the adapter is in the dose setting state, the first member is rotationally locked to the second member.

[0079] In general, the scope of the present disclosure is defined by the content of the claims. The injection device is not limited to a specific embodiment or example, but includes any combination of elements of different embodiments or examples. In this regard, the present disclosure covers any combination of claims and any technically feasible combination of features disclosed in combination with different examples or embodiments.

[0080] In the present context, the term "distal" or "distal end" relates to the end of the injection device facing the injection site of a person or animal. The term "proximal" or "proximal end" relates to the opposite end of the injection device, which is farthest from the injection site of a person or animal.

[0081] As used herein, the term "drug" or "medicament" refers to a pharmaceutical formulation containing at least one pharmaceutically active compound.

[0082] In one embodiment, the pharmaceutically active compound has a molecular weight of up to 1500 Da, and / or is a peptide, protein, polysaccharide, vaccine, DNA, RNA, enzyme, antibody or antibody fragment, hormone or oligonucleotide, or a mixture of the above pharmaceutically active compounds,

[0083] Wherein in other embodiments, the pharmaceutically active compound can be used to treat and / or prevent diabetes or complications associated with diabetes (such as diabetic retinopathy), thromboembolic disease (such as deep vein or pulmonary thromboembolism), acute coronary syndrome (ACS), angina pectoris, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and / or rheumatoid arthritis,

[0084] Wherein in another embodiment, the pharmaceutically active compound comprises at least one peptide for the treatment and / or prevention of diabetes or complications associated with diabetes (such as diabetic retinopathy),

[0085] In other embodiments, the pharmaceutically active compound includes at least one human insulin or human insulin analog or derivative, glucagon-like peptide (GLP-1) or an analog or derivative thereof, or exendin-3 or exendin-4, or an analog or derivative of exendin-3 or exendin-4.

[0086] Insulin analogs are, for example, Gly(A21), Arg(B31), Arg(B32) human insulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin in which the proline at position B28 is replaced by Asp, Lys, Leu, Val or Ala, and in which position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

[0087] Insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoylLysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB2 9LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-γ-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-γ-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyheptadecanoyl) human insulin.

[0088] Exendin-4 refers, for example, to exendin-4 (1-39), a peptide having the following sequence: H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

[0089] The exendin-4 derivative is, for example, selected from the following list of compounds:

[0090] H-(Lys)4-des Pro36,des Pro37 exendin-4(1-39)-NH2,

[0091] H-(Lys)5-des Pro36,des Pro37 exendin-4(1-39)-NH2,

[0092] des Pro36 exendin-4 (1-39),

[0093] des Pro36[Asp28] exendin-4(1-39),

[0094] des Pro36[IsoAsp28] exendin-4(1-39),

[0095] des Pro36[Met(O)14,Asp28]exendin-4(1-39),

[0096] des Pro36[Met(O)14,IsoAsp28]exendin-4(1-39),

[0097] des Pro36[Trp(O2)25,Asp28]exendin-4(1-39),

[0098] des Pro36[Trp(O2)25,IsoAsp28]exendin-4(1-39),

[0099] des Pro36[Met(O)14Trp(O2)25,Asp28]exendin-4(1-39),

[0100] des Pro36[Met(O)14Trp(O2)25,IsoAsp28]exendin-4(1-39); or

[0101] des Pro36[Asp28] exendin-4(1-39),

[0102] des Pro36[IsoAsp28] exendin-4(1-39),

[0103] des Pro36[Met(O)14,Asp28]exendin-4(1-39),

[0104] des Pro36[Met(O)14,IsoAsp28]exendin-4(1-39),

[0105] des Pro36[Trp(O2)25,Asp28]exendin-4(1-39),

[0106] des Pro36[Trp(O2)25,IsoAsp28]exendin-4(1-39),

[0107] des Pro36[Met(O)14Trp(O2)25,Asp28]exendin-4(1-39),

[0108] des Pro36[Met(O)14Trp(O2)25,IsoAsp28]exendin-4(1-39),

[0109] The group -Lys6-NH2 can bind to the C-terminus of the exendin-4 derivative;

[0110] or an exendin-4 derivative having the following sequence:

[0111] des Pro36 exendin-4(1-39)-Lys6-NH2(AVE0010),

[0112] H-(Lys)6-des Pro36[Asp28] exendin-4(1-39)-Lys6-NH2,

[0113] des Asp28 Pro36,Pro37,Pro38 Exendin-4(1-39)-NH2,

[0114] H-(Lys)6-des Pro36,Pro38[Asp28]exendin-4(1-39)-NH2,

[0115] H-Asn-(Glu)5des Pro36,Pro37,Pro38[Asp28]exendin-4(1-39)-NH2,

[0116] des Pro36, Pro37, Pro38 [Asp28] exendin-4 (1-39) - (Lys) 6-NH2,

[0117] H-(Lys)6-des Pro36,Pro37,Pro38[Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0118] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0119] H-(Lys)6-des Pro36[Trp(O2)25,Asp28] exendin-4(1-39)-Lys6-NH2,

[0120] H-des Asp28 Pro36,Pro37,Pro38[Trp(O2)25]exendin-4(1-39)-NH2,

[0121] H-(Lys)6-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28]exendin-4(1-39)-NH2,

[0122] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28]exendin-4(1-39)-NH2,

[0123] des Pro36, Pro37, Pro38 [Trp (O2) 25, Asp28] exendin-4 (1-39) - (Lys) 6-NH2,

[0124] H-(Lys)6-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0125] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0126] H-(Lys)6-des Pro36[Met(O)14,Asp28] exendin-4(1-39)-Lys6-NH2,

[0127] des Met(O)14Asp28 Pro36,Pro37,Pro38 Exendin-4(1-39)-NH2,

[0128] H-(Lys)6-desPro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-NH2,

[0129] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-NH2,

[0130] des Pro36, Pro37, Pro38 [Met (O) 14, Asp28] exendin-4 (1-39) - (Lys) 6-NH2,

[0131] H-(Lys)6-des Pro36,Pro37,Pro38[Met(O)14,Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0132] H-Asn-(Glu)5des Pro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-(Lys)6-NH2,

[0133] H-Lys6-des Pro36[Met(O)14,Trp(O2)25,Asp28]exendin-4(1-39)-Lys6-NH2,

[0134] H-des Asp28 Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25]exendin-4(1-39)-NH2,

[0135] H-(Lys)6-des Pro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-NH2,

[0136] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]exendin-4(1-39)-NH2,

[0137] des Pro36, Pro37, Pro38 [Met (O) 14, Trp (O2) 25, Asp28] exendin-4 (1-39) - (Lys) 6-NH2, H- (Lys) 6-des Pro36, Pro37, Pro38 [Met (O) 14, Trp (O2) 25, Asp28] exendin-4 (S1-39) - (Lys) 6-NH2,

[0138] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]exendin-4(1-39)-(Lys)6-NH2;

[0139] Or a pharmaceutically acceptable salt or solvate of any of the above exendin-4 derivatives.

[0140] Hormones are, for example, pituitary hormones or hypothalamic hormones or regulatory active peptides as listed in Chapter 50 of the Rote Liste, 2008 edition, and their antagonists, such as gonadotropins (Follitropin, Luteinizing Hormone, Choriongonadotropin, Gametogenic Hormone), somatropine (Somatropin), desmopressin, terlipressin, gonadorelin, triptorelin, leuprorelin, buserelin, nafarelin, goserelin.

[0141] The polysaccharide is, for example, a glycosaminoglycan, hyaluronic acid, heparin, a low molecular weight heparin or an ultra-low molecular weight heparin or a derivative thereof, or a sulfated form (e.g., a polysulfated form) of the polysaccharide, and / or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a polysulfated low molecular weight heparin is enoxaparin sodium.

[0142] Antibodies are globular plasma proteins (about 150 kDa), also called immunoglobulins, that share a basic structure. They are glycoproteins because of the addition of sugar chains to amino acid residues. The basic functional unit of each antibody is the immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimers with two Ig units (such as IgA), tetramers with four Ig units (such as bony fish IgM), or pentamers with five Ig units (such as mammalian IgM).

[0143] The Ig monomer is a "Y" shaped molecule composed of four polypeptide chains; two identical heavy chains and two identical light chains are connected by disulfide bonds between cysteine ​​residues. Each heavy chain is about 440 amino acids long; each light chain is about 220 amino acids long. The heavy and light chains each contain intrachain disulfide bonds that stabilize their folding. Each chain is composed of domains called Ig domains. These domains contain about 70-110 amino acids and are divided into different categories (such as variable regions or V regions and constant regions or C regions) based on their size and function. These domains have a characteristic immunoglobulin fold in which two beta folds are "sandwiched" together by interactions between conserved cysteines and other charged amino acids.

[0144] There are five types of mammalian Ig heavy chains, denoted α, δ, ε, γ, and μ. The type of heavy chain present defines the antibody's isotype; these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively.

[0145] The different heavy chains vary in size and composition; α and γ contain about 450 amino acids, δ contains about 500 amino acids, and μ and ε contain about 550 amino acids. Each heavy chain has a constant region (C H ) and variable region (V H ) two regions. In one species, the constant region is essentially the same in all antibodies of the same isotype, but different in antibodies of different isotypes. Heavy chains γ, α, and δ have a constant region consisting of three tandem Ig domains, and a hinge region for increased flexibility; heavy chains μ and ε have a constant region consisting of four immunoglobulin domains. The variable region of the heavy chain is different in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is about 110 amino acids long and consists of a single Ig domain.

[0146] In mammals, there are two types of immunoglobulin light chains, denoted by λ and κ. A light chain has two consecutive domains: a constant domain (CL) and a variable domain (VL). The approximate length of a light chain is 211 to 217 amino acids. Each antibody contains two light chains that are always identical; in mammals, only one type of light chain, κ or λ, exists for each antibody.

[0147] Although the general structure of all antibodies is very similar, the unique properties of a given antibody are determined by the variable (V) regions as detailed above. More specifically, the variable loops (three per light chain (VL) and three on the heavy chain (VH)) are responsible for binding to the antigen, i.e., for its antigen specificity. These loops are called complementarity determining regions (CDRs). Because the CDRs from the VH domain and the VL domain constitute the antigen binding site, it is the combination of the heavy and light chains (rather than each alone) that determines the final antigen specificity.

[0148] "Antibody fragments" contain at least one antigen-binding fragment as defined above, and exhibit essentially the same function and specificity as the complete antibody from which they are derived. Limited proteolysis with papain cleaves the Ig prototype into three fragments. Two identical amino-terminal fragments are antigen-binding fragments (Fab), each containing a complete L chain and about half of an H chain. The third fragment is a crystallizable fragment (Fc), which is similar in size but contains the carboxyl-terminal half of the two heavy chains and their interchain disulfide bonds. Fc contains carbohydrates, complement binding sites, and FcR binding sites. Limited pepsin digestion produces a single F(ab')2 fragment containing both the Fab segment and the hinge region, including the HH interchain disulfide bonds. F(ab')2 is divalent for antigen binding. The disulfide bonds of F(ab')2 can be cleaved to obtain Fab'. In addition, the variable regions of the heavy and light chains can be fused together to form a single-chain variable fragment (scFv).

[0149] Pharmaceutically acceptable salts are, for example, acid addition salts and alkaline salts. Acid addition salts are, for example, HCl salts or HBr salts. Alkaline salts are, for example, salts with cations selected from: alkali or alkaline, for example, Na+, or K+, or Ca2+, or ammonium ions N+(R1)(R2)(R3)(R4), wherein R1 to R4 represent, independently of one another: hydrogen, optionally substituted C1-C6-alkyl groups, optionally substituted C2-C6-alkenyl groups, optionally substituted C6-C10-aryl groups, or optionally substituted C6-C10-heteroaryl groups. Other examples of pharmaceutically acceptable salts are described in the following documents: "Remington's Pharmaceutical Sciences" 17th edition Alfonso R.Gennaro (ed.), Mark Publishing Company, Easton, Pa., USA, 1985 and Encyclopedia of Pharmaceutical Technology.

[0150] Pharmaceutically acceptable solvates are, for example, hydrates.

[0151] It is also clear to those skilled in the art that various modifications and variations may be made to the present disclosure without departing from the scope of the present disclosure. In addition, it should be noted that any reference signs used in the appended claims should not be construed as limiting the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0152] In the following, a number of examples of injection devices including a filling level indicator will be described in more detail with reference to the accompanying drawings,

[0153] in:

[0154] FIG. 1 shows an example of an injection device,

[0155] FIG. 2 shows the injection device of FIG. 1 in an exploded perspective view,

[0156] FIG3 shows a section through an injection device,

[0157] FIG. 4 is an enlarged view of a portion of FIG. 3 with the fill level indicator in an initial configuration,

[0158] FIG. 5 is a diagram corresponding to FIG. 4 , with the fill level indicator in an intermediate configuration,

[0159] FIG. 6 is an enlarged view of a portion of the housing of the injection device according to FIG. 4 , seen from the outside;

[0160] FIG7 is an enlarged view of a portion of the housing of the injection device according to FIG5 as seen from the outside;

[0161] FIG8 is a transverse section through the fill level indicator engaged with the housing,

[0162] FIG. 9 is a longitudinal section through a further example of a fill level indicator, and

[0163] FIG. 10 is a transverse section through the fill level indicator according to FIG. 9 . DETAILED DESCRIPTION

[0164] One of the examples of injection devices 1 suitable for implementing a filling level indication of a cartridge is shown in Figures 1 and 2. Here, the injection device 1 is a prefilled disposable injection device, which includes a housing 90 to which an injection needle 15 can be attached. The housing 90 includes a body 10 forming the proximal end of the housing and a cartridge holder 14 forming the distal end of the injection device 1. The injection needle 15 is protected by an inner needle cap 16 and an outer needle cap 17 and / or a protective cap 18, which is configured to surround and protect the distal section of the housing 90 of the injection device 1. The housing 90 includes a body 10 configured to accommodate a drive mechanism 8 as shown in Figure 2. The distal housing component is generally represented as a cartridge holder 14. The cartridge holder 14 can be permanently or releasably connected to the body 10.

[0165] The body 10 may form or constitute the main body or main housing of the injection device 10. In addition, according to the terminology of the present disclosure, the body 10 may form or constitute a second member. The cartridge holder 14 is typically configured to accommodate a cartridge 6 filled with a liquid medicament. The cartridge 6 includes a cylindrical or tubular barrel 25, which is sealed in the proximal direction 3 by a stopper 7 located inside the barrel 25. The stopper 7 can be displaced in the distal direction 2 relative to the barrel 25 of the cartridge 6 by the piston rod 20. The distal end of the cartridge 6 is sealed by a pierceable seal 26, which is configured as a septum and can be pierced by the proximal pointed tip of the injection needle 15. The cartridge holder 14 includes a threaded socket 28 at its distal end to threadably engage with a corresponding threaded portion of the injection needle 15. By attaching the injection needle 15 to the distal end of the cartridge holder 14, the seal 26 of the cartridge 6 is penetrated, thereby establishing a fluid transfer passage to the interior of the cartridge 6.

[0166] When the injection device 1 is configured to administer, for example, human insulin, the dose set by the dose dial 12 at the proximal end of the injection device 1 can be displayed in so-called international units (IU, where 1 IU is the biological equivalent of about 45.5 μg pure crystalline insulin (1 / 22 mg)). The dose dial 12 can be rotated relative to the housing 90 or body 10 about the longitudinal axis.

[0167] As further shown in Figures 1 and 2, the body 10 includes a dose window 13, which may be in the form of an aperture in the body 10. The dose window 13 allows a user to view a limited portion of a number sleeve 80, which is configured to move when the dose dial 12 is turned to provide a visual indication of the currently set dose. When turned during dose setting and / or dispensing or expelling, the dose dial 12 rotates on a spiral path relative to the body 10.

[0168] The injection device 1 can be configured so that turning the dose knob or dose dial 12 causes a mechanical click to provide acoustic feedback to the user. The number sleeve 80 mechanically interacts with the piston in the insulin cartridge 6. When the needle 15 is inserted into the skin portion of the patient and when the trigger 11 or injection button is pushed, the insulin dose displayed in the display window 13 will be ejected from the injection device 1. When the needle 15 of the injection device 1 is retained in the skin portion for a certain time after the trigger 11 is pushed, a higher percentage of the dose is actually injected into the patient. The ejection of the insulin dose can also cause a mechanical click, but it is different from the sound produced when the dose dial 12 is used.

[0169] In this embodiment, during insulin dose delivery, the dose dial 12 is rotated to its initial position in axial movement, ie, no rotation, while the number sleeve 80 is rotated to return to its initial position, eg, to display a dose of zero units.

[0170] The injection device 1 can be used for several injection procedures until the cartridge 6 is empty or the medicament in the injection device 1 reaches an expiration date (eg, 28 days after first use).

[0171] Furthermore, before using the injection device 1 for the first time, it may be necessary to perform a so-called "pre-injection" to remove air from the cartridge 6 and the needle 15, for example by selecting two units of medicament and pressing the trigger 11 while keeping the needle 15 of the injection device 1 pointing upwards. For ease of presentation, in the following it will be assumed that the ejected amount substantially corresponds to the injected dose, such that, for example, the amount of medicament ejected from the injection device 1 is equal to the dose received by the user.

[0172] An example of a drive mechanism 8 is shown in more detail in FIG. 2 . It comprises a plurality of mechanically interacting components. The flange-like support of the body 10 comprises a threaded axial through-opening which is threadedly engaged with a first or distal thread 22 of the piston rod 20. The distal end of the piston rod 20 comprises a bearing 21 on which a pressure foot 23 can freely rotate with the longitudinal axis of the piston rod 20 as the axis of rotation. The pressure foot 23 is configured to axially abut against a proximally facing thrust receiving surface of the bung 7 of the cartridge 6. During the dispensing action, the piston rod 20 rotates relative to the body 10, thereby undergoing a distally directed thrust movement relative to the body 10 and therefore relative to the barrel 25 of the cartridge 6. As a result, due to the threaded engagement of the piston rod 20 with the body 10, the bung 7 of the cartridge 6 is displaced by a well-defined distance in the distal direction 2.

[0173] The piston rod 20 is further provided at its proximal end with a second thread 24. The distal thread 22 and the proximal thread 24 have opposite rotation directions.

[0174] A dose setting member 30 is further provided, for example forming or constituting a drive sleeve. The dose setting member 30 or the drive sleeve may form or constitute a first member according to the terminology of the present disclosure. Here, the first member 30, for example in the form of a dose setting member 30 or a drive sleeve, has a hollow interior to receive the piston rod 20. The dose setting member 30 comprises an internal thread that is threadedly engaged with the proximal thread 24 of the piston rod 20. Furthermore, the dose setting member 30 comprises an external thread section 31 at its distal end. The thread section 31 is axially defined between a first stop 32 and a second stop 33. The first stop 32 comprises a distal flange portion. The second stop 33 comprises a proximal flange portion located at a predetermined axial distance from the distal flange portion 32. A filling level indicator 35 is provided between the two flange portions 32, 33. In the present example, the filling level indicator 35 comprises a semicircular nut having an internal thread 38 that cooperates with the thread section 31 of the dose setting member 30. The fill level indicator 35 may also form or constitute a last-dose limiter, for example in the form of a last-dose nut.

[0175] The fill level indicator 35 further comprises radial recesses or protrusions 39 at its outer circumference to engage with complementary shaped recesses 99 or protrusions at the inner side of the side wall of the body 10. In this way, the fill level indicator 35 is splined to the body 10. During the continuous dose setting procedure, the rotation of the dose setting member 30 in the dose increment direction 4 or clockwise direction causes the cumulative axial displacement of the fill level indicator 35 relative to the dose setting member 30. An annular spring 40 is further provided, which is axially adjacent to the proximal facing surface of the flange portion 33. In addition, a tubular adapter 60 is provided. At a first end, the adapter 60 is provided with a series of circumferentially directed serrations. Towards the second opposite end of the adapter 60, a radially inwardly directed flange is located.

[0176] Furthermore, a dose dial sleeve, also indicated as number sleeve 80, is provided. The number sleeve 80 is arranged outside the spring 40 and the adapter 60 and is located radially inside the body 10. A spiral groove 81 is provided around the outer surface of the number sleeve 80. The body 10 is provided with a dose window 13, through which a part of the outer surface of the number 80 can be seen. The body 10 is further provided with a spiral rib at the inner side wall portion of the insert 62, which will seat in the spiral groove 81 of the number sleeve 80. The tubular insert 62 is inserted into the proximal end of the body 10. It is rotationally and axially fixed to the body 10. A first stopper and a second stopper are provided on the body 10 to limit a dose setting procedure during which the number sleeve 80 rotates in a spiral motion relative to the body 10.

[0177] A dose dial 12 in the form of a dose dial grip is disposed around the outer surface of the proximal end of the number sleeve 80. The outer diameter of the dose dial 12 typically corresponds to and matches the outer diameter of the body 10. The dose dial 12 is secured to the numbers 80 to prevent relative movement therebetween. The dose dial 12 is provided with a central opening.

[0178] The trigger 11 (also indicated as a dose button) is substantially T-shaped. It is disposed at the proximal end of the injection device 10. The handle 64 of the trigger 11 extends through an opening in the dose dial 12, through the inner diameter of an extension of the dose setting member 30, and into a receiving recess at the proximal end of the piston rod 20. The handle 64 is retained for limited axial movement in the dose setting member 30 and prevented from rotating relative to the dose setting member. The head of the trigger 11 is generally circular. A trigger sidewall or skirt extends from the periphery of the head and is further adapted to seat in a proximally accessible annular recess of the dose dial 12.

[0179] To dial a dose, the user rotates the dose dial 12. With the spring 40 also acting as a clicker and the adapter 60 engaged, the dose setting member 30, the spring or clicker 40, the adapter 60, and the number sleeve 80 rotate together with the dose dial 12. Audible and tactile feedback of the dialed dose is provided by the spring 40 and by the adapter 60. Torque is transmitted by the sawtooth between the spring 40 and the adapter 60. The helical groove 81 on the number sleeve 80 and the helical groove in the dose setting member 30 have the same lead. This allows the number sleeve 80 to extend from the body 10 and the dose setting member 30, climbing up the piston rod 20 at the same rate. At the limit of travel, the radial stop on the number sleeve 80 engages with the first stop or the second stop provided on the body 10 to prevent further movement in the first rotational direction (e.g., in the dose incrementing direction 4). Due to the opposite directions of the integral thread and the drive thread on the piston rod 20, the rotation of the piston rod 20 is prevented.

[0180] By rotation of the dose setting member 30, the filling level indicator 35 keyed to the body 10 is advanced along the threaded section 31. When the final dose dispensing position is reached, a radial stopper formed on the surface of the filling level indicator 35 may abut against the second stopper 33 of the dose setting member 30 or a radial stopper on the proximal flange portion, thereby preventing further rotation of both the filling level indicator 35 and the dose setting member 30.

[0181] If the user inadvertently dials more than the desired dose, the injection device 1 configured as a pen injector allows dialing a smaller dose without dispensing the medicament from the cartridge 6. This is done by simply rotating the dose dial 12 in the opposite direction. This causes the system to act in reverse. The flexible arm of the spring or clicker 40 then acts as a ratchet that prevents the spring 40 from rotating. The torque transmitted through the adapter 60 causes the saw teeth to overlap each other, thereby producing a click corresponding to the decrease in the dialed dose. Typically, the saw teeth are arranged so that the circumferential extension of each saw tooth corresponds to a unit dose. Here, the adapter can act as a ratchet mechanism.

[0182] Alternatively or additionally, the ratchet mechanism may include at least one ratchet feature, such as a flexible arm on the side wall of the tubular adapter 60. The at least one ratchet feature may include, for example, a radially outwardly extending protrusion on the free end of the flexible arm. The protrusion is configured to engage with a correspondingly shaped reverse ratchet structure on the inner side of the number sleeve 80. The interior of the number sleeve 80 may include a longitudinally shaped groove or protrusion characterized by a sawtooth profile. During the process of dialing or setting a dose, the ratchet mechanism allows and supports the rotation of the number sleeve 80 relative to the adapter 60 in the second rotational direction 5, and the rotation is accompanied by a regular click of the flexible arm of the adapter 60. The angular momentum applied to the number sleeve 80 in the first rotational direction is transmitted to the adapter 60 unchanged. Here, the mutually corresponding ratchet features of the ratchet mechanism provide torque transmission from the number sleeve 80 to the adapter 60.

[0183] When the desired dose has been dialed, the user can simply dispense the set dose by depressing the trigger 11. This causes the adapter 60 to be axially displaced relative to the number sleeve 80, causing its claws to disengage. However, the adapter 60 remains keyed to the dose setting member 30 for rotation. The number sleeve 80 and the dose dial 12 can now rotate freely according to the helical groove 81.

[0184] The axial movement deforms the flexible arms of the spring 40 to ensure that the serrations are not overhauled during dispensing. This prevents the dose setting member 30 from rotating relative to the body 10, although it is still free to move axially relative thereto. The deformation is then used to push the spring 40 and the adapter 60 back along the dose setting member 30 to restore the connection between the adapter 60 and the number sleeve 80 when the distally directed dispensing pressure is removed from the trigger 11.

[0185] The longitudinal axial movement of the dose setting member 30 causes the piston rod 20 to rotate through the through opening of the support of the body 10, thereby advancing the bung 7 in the cartridge 6. Once the dialed dose has been dispensed, the number sleeve 80 is prevented from further rotation by contact of at least one stop extending from the dose dial 12 with at least one corresponding stop of the body 10. The zero dose position may be determined by abutment of one of the axially extending edges or stops of the number sleeve 80 with at least one or several corresponding stops of the body 10.

[0186] The expelling mechanism or drive mechanism 8 as described herein is only an embodiment of one of a plurality of different configurations of drive mechanisms that can be implemented in a disposable pen injector as a whole. The drive mechanism as described above is explained in more detail in, for example, WO 2004 / 078239 A1, WO 2004 / 078240 A1 or WO 2004 / 078241 A1, the entire contents of which are incorporated herein by reference.

[0187] In general, the fill level indication mechanism as disclosed herein can be implemented with any injection device comprising a first member 30 and a second member 10, wherein the first member 30 rotates relative to the second member 10 during and / or for only one of dose setting and dose expelling, and wherein the first member 30 is rotationally locked to the second member 10 during and / or for only one of the other of dose setting and dose expelling. In this document, any reference to the dose setting member 30 may equally apply to the first member. Furthermore, according to the terms of the appended claims, any reference to the body 10 or the housing 90 may equally apply to the second member.

[0188] 2 , the dose setting mechanism 9 comprises at least a dose dial 12 and a number sleeve 80. When the dose dial 12 is rotated during and for dose setting, the number sleeve 80 begins to rotate relative to the housing along a helical path defined by the threaded engagement of the outer thread or helical groove 81 of the number sleeve with a correspondingly shaped threaded section at the inner surface of the housing.

[0189] During dose setting and when the drive mechanism 8 or the dose setting mechanism 9 is in dose setting mode, the dose setting member 30 rotates in unison with the dose dial 12 and with the number sleeve 80. The dose setting member 30 is threadedly engaged with the piston rod 20, which is stationary with respect to the body 10 during dose setting. Thus, the dose setting member 30 is subjected to a screwing or spiral motion during dose setting. As the dose dial is rotated in a first rotational direction or in a dose increasing direction 4 (e.g., in a clockwise direction), the dose setting member 30 starts to travel in a proximal direction. In order to adjust or correct the size of the dose, the dose dial 12 can be rotated in an opposite second rotational direction, thus in a dose decreasing direction 5 (e.g., counterclockwise).

[0190] 1 to 5 , the proximal end of the cartridge holder 14 may be connected or permanently connected to the distal end of the body 10. To this end, the cartridge holder 14 may include an insertion section configured to be inserted into a receiving seat provided at the distal end of the body 10. The cartridge holder 14 and the body 10 may be detachably or releasably engaged.

[0191] For some examples, the cartridge holder 14 and the body 10 are permanently and / or non-releasably or non-detachably engaged (e.g., by a snap-fit ​​interconnection provided, for example, by an adhesive or by mutual welding of overlapping portions of the cartridge holder 14 and the body 10 and / or by a force-fit engagement). For examples in which the cartridge holder 14 and the body 10 are non-detachably interconnected, the injection device itself is implemented as a disposable injection device that is intended to be completely discarded once the contents of the cartridge have been used up or should no longer be used.

[0192] The first member 30 and thus the dose setting member 30 may be realized as a drive sleeve and configured to rotate in a dose increasing direction during dose setting. In order to correct the dose of the dose setting member, the dose setting member may be rotated in the opposite direction, thus in a dose decreasing direction, relative to the first member and thus relative to the housing 90 or body 10. During dose expulsion or dose dispensing, the dose setting member 30 is typically rotationally locked to the housing.

[0193] The filling level indicator 35 of the injection device 1 is engaged with the dose setting member 30. The filling level indicator 35 is further engaged with the elongated housing 90, in particular with the proximally located tubular body 10. In the illustration of FIG. 4 , the filling level indicator 35 is located in a starting position 100. There, it abuts against a first stop 32 provided on the dose setting member 30. The position of the filling level indicator 35, in particular the starting position 100, can be discerned from the outside of the housing by an elongated aperture 91 provided in a side wall of the housing 90, in particular in a side wall of the body 10, as indicated in FIGS. 4 to 7 .

[0194] In the present example, the filling level indicator 35; 135 provides a dual function. On the one hand, it provides the function of a last-dose member or last-dose nut. On the other hand, the filling level indicator 35; 135 indicates the filling level of the medicament provided in the cartridge 6. Here, the longitudinal position of the filling level indicator 35; 135 relative to the housing 90 or body 10 is directly related to the longitudinal position of the piston rod 20 relative to the housing 90 or body 10. In each configuration of the injection device, the filling level indicator can be visually inspected and / or discernible from outside the housing 90.

[0195] In FIGS. 4 to 10 , various examples of filling level indicators 35; 135 are shown in conjunction with a specific example of an injection device 1. In general, the concept of the filling level indicator 35; 135 disclosed in the present disclosure can be implemented with various different injection devices. For some examples and for the implementation of the filling level indicator 35; 135, it is only required that the first member 30 (e.g., the dose setting member 30) can be rotated relative to the second member 10 (e.g., the body 10) in the dose increment direction during the dose setting process and cannot be rotated during the dose expulsion or dose injection process. For other examples, during the dose setting process and / or for setting the dose, the first member is rotationally locked to the second member 10. Then, during the dose expulsion process and / or for expelling the dose, the first member can be rotated relative to the second member 20.

[0196] In the presently illustrated non-limiting example, the fill level indicator 35 is threadedly engaged with the dose setting member 30. To this end, the fill level indicator 35 comprises an internal threaded section 38 threadedly engaged with a correspondingly shaped external threaded section 31 of the dose setting member 30. The dose setting member 30 comprises a tubular or sleeve-shaped geometry.

[0197] The threaded section 31 extends in the longitudinal direction on the outer surface of the dose setting member 30. The threaded section 31 is bounded in the proximal direction 3 by a second stop 33. The threaded section 31 is bounded in the distal direction 2 by a first stop 32. In the example currently shown, the first stop 32 comprises a radially outwardly extending flange portion formed integrally with the dose setting member 30. Likewise, the second stop 33 is also realized as a radially outwardly extending flange portion. In particular and as shown in FIG. 4 , a stop feature 29 of the distally pointing side of the second stop 33 may be provided. The stop feature 34 may comprise a stop surface, wherein the stop surface extends in the longitudinal and radial directions. Thus, the surface normal of the stop surface of the stop feature 29 extends in the tangential or circumferential direction.

[0198] The filling level indicator 35 may comprise a semicircular half nut, as illustrated in FIG8 . Alternatively, the filling level indicator 35 may be axially engaged with the second stop 33, in particular with the distally directed surface of the flange. Alternatively or additionally, the filling level indicator 35 may comprise stop features 44, 45 at the circumferential or tangential ends, which are configured to abut against the stop feature 29 of the second stop 33 in the tangential or circumferential direction. In this way, when the filling level indicator 35 reaches the end position 102, a rather abrupt and clearly defined stop configuration may be provided, as indicated by the dashed rectangle in FIG6 .

[0199] At least the indicating portion 36 of the filling level indicator 35 (in particular the side wall portion of the filling level indicator 35 facing outwards) is visually discernible or visible from the outside of the housing 90. To this end, the housing 90 (in particular the body 10, for example also representing the second member) comprises an elongated aperture 91, as illustrated in Figures 4 to 8. The elongated aperture 91 comprises a longitudinal extension that is the same as or substantially matches the longitudinal extension between the first stop 32 and the second stop 33 of the dose setting member 30. In this way, the longitudinal position of the filling level indicator 35 from the starting position 100 towards the end position 102 is always and / or completely visible. As indicated in Figure 8, the elongated aperture 91 can be covered or closed by a transparent window 92. In this way, the interior of the body 10 or housing 90 is substantially protected from the ingress of moisture and / or particles.

[0200] Outside the elongated aperture 91 and circumferentially or tangentially offset therefrom, the housing 90 or body 10 comprises at least one or several radial recesses 99 which are configured to engage with correspondingly shaped radial protrusions 39 of the fill level indicator 35. Here, the radial protrusions 39 extend radially outwards from the outer surface of the fill level indicator 35. The correspondingly shaped recesses 99 are provided on an inwardly facing portion of the side wall of the body 10 or housing 90. The interior of the fill level indicator 35 is provided with a threaded section 38 which is threadedly engaged with an outer counter-threaded section 31 of the dose setting member 30.

[0201] The recess 99 provides a sliding track for the fill level indicator 35. The splined engagement of the protrusion 39 with the recess 99 rotationally locks the fill level indicator 35 to the body 10 or housing 90, thereby enabling longitudinal sliding movement of the fill level indicator 35 in the longitudinal direction relative to the body 10. The longitudinal sliding displacement of the fill level indicator 35 relative to the body 10 is caused by the rotation of the dose setting member 30 relative to the body 10. Here, the degree of rotation of the dose setting member 30 directly matches the size of the dose.

[0202] An indication portion 36 is provided on the outer surface of the filling level indicator 35. The indication portion 36 is the portion of the filling level indicator 35 which is visible from the outside of the housing 90.

[0203] The fill level indicator 35 further comprises a base portion 34. The base portion 34 is the portion of the fill level indicator 35 which mechanically engages with the dose setting member 30 and with the housing 90 or body 10.

[0204] A scale 94 is provided on the outer surface of the shell 90 or the body 10 and along the longitudinal extension of the longitudinal aperture 91, and the scale is provided with a plurality of marks, texts, symbols or numbers, which help indicate the residual amount of medicine set in the cartridge when the fill level indicator 35 is positioned adjacent to the corresponding portion of the scale 94.

[0205] In the configurations illustrated in Figures 4 and 6, the injection device 1 and the drive mechanism 8 are in an initial configuration. The piston rod 20 is in a proximal starting position and the amount of medicament inside the cartridge is substantially equal to the initial fill amount. In this initial configuration, no dose of medicament has yet been expelled from the cartridge 6. Therefore, the fill level indicator 35 is located at or near the first longitudinal end 93 of the elongated aperture 91, thus indicating that the initial fill volume of the cartridge is still available.

[0206] When a dose of medicament is set by rotating the dose setting member 30 relative to the housing 90, the fill level indicator 35 becomes subject to a sliding movement along the elongated aperture 91 towards the end position 102, as indicated in Figure 6. The amount of longitudinal displacement is indicated by the pointer 37 of the indicating portion 36, which points to a specific mark and / or indication of the scale 94, as indicated in Figure 7.

[0207] When the dose has been set and when the fill level indicator 35 has moved towards the end position 102, the piston rod 20 remains positionally locked to the housing 90 or body 10. Only during a subsequent dose dispensing or dose expelling procedure is the piston rod 20 advanced in the distal direction relative to the barrel 25 of the cartridge 6, thereby expelling a corresponding medicament dose from the cartridge, typically through the injection needle 15 penetrating an injection site of the patient.

[0208] In the intermediate position 101 of the fill level indicator 35 as indicated in Figures 5 and 7, the fill level indicator 35 is separated in the longitudinal direction from both the first stop 32 and the second stop 33. The distance to the second stop 33 and therefore the distance between the indicating portion 36 and the second longitudinal end 95 of the longitudinal aperture 91 indicates the residual amount of medicament still available in the cartridge 6. The patient or user of the device immediately knows the residual content of the cartridge without having to disassemble or remove the protective cap 18 from the cartridge holder 14 to visually check the medicament in the cartridge.

[0209] In this way, and since the filling level indicator 35 instantly indicates the remaining filling level of the cartridge, the cartridge holder 14 can be made of an opaque material and the medicament located inside the cartridge 6 can be surrounded by the non-transparent and therefore opaque cartridge holder. In this way, when assembled inside the injection device 1 and when received in the cartridge holder 14, the medicament located inside the cartridge 6 can be protected from electromagnetic radiation.

[0210] In a further example as illustrated in Figures 9 and 10, the fill level indicator 135 further comprises an internal threaded section 138 threadedly engaged with the threaded section 31 of the dose setting member 30. Here too, a radial protrusion 139 of the fill level indicator 135 is slidably engaged with the housing 90 or the body 10 of the injection device 1. Here too, the fill level indicator 135 comprises a base portion 134 mechanically engaged with both the housing 90 and the dose setting member 30. In contrast to the examples described above in conjunction with Figures 4, 5 and 8, the fill level indicator 135 comprises an indication portion 142 located outside the housing 90 or outside the body 10.

[0211] Here, the filling level indicator 135 includes an L-shaped rod 140, which includes an indicating portion 142 and a bridging portion 141. The bridging portion 141 is connected to the longitudinal end of the elongated indicating portion 142 or is formed integrally therewith. It is also connected to the base portion 134 of the filling level indicator 135 or is formed integrally therewith. The bridging portion 141 extends through the elongated aperture 91 in the housing 90 or body 10. In this way, the bridging portion 141 is in longitudinal spline engagement or sliding engagement with the housing 90 or body 10. Therefore, it is rotationally locked to the housing 90 or body 10 by the bridging portion 141. The tangential width of the bridging portion 141 can substantially match or correspond to the tangential size of the elongated aperture 91. In this way, a substantially slack-free sliding engagement between the housing 90 or body 10 and the filling level indicator 135 can be provided.

[0212] For this example, the additional protrusion 139 of the fill level indicator 135 may become superfluous. For this purpose, the fill level indicator 135 may also be realized without the radially outwardly extending protrusion 139. Thus, the housing 90 or the body 10 may also be without the elongated recess 99. The longitudinal sliding engagement between the housing 90 and the fill level indicator 135 may be provided exclusively and obtained by a bridge portion 141 extending through the elongated aperture 91 of the housing.

[0213] The bridge portion 141 further comprises at least one stop surface 144 facing towards the end position 102 and thus towards the second longitudinal end 95 of the elongated orifice 91. When approaching the end position 102, the stop surface 144 can abut against the second longitudinal end 95 of the elongated orifice 91, thereby preventing any further displacement of the filling level indicator 135 beyond the end position 102.

[0214] Due to the threaded engagement between the fill level indicator 135 and the dose setting member 30 , further dose incrementing rotation of the dose setting member for setting a dose that would exceed the amount of medicament remaining in the cartridge 6 may be effectively prevented.

[0215] In this regard, the fill level indicator 135 performs a dual function. On the one hand, the fill level indicator 135 visually displays the remaining amount of medicament provided in the cartridge 6. On the other hand, the fill level indicator 135 provides an end stop that prevents dialing or setting a dose that exceeds the remaining amount of medicament provided in the cartridge.

[0216] For the example of FIGS. 9 and 10 , the elongated aperture 91 of the housing 90 does not cover the window 92. Instead, the corresponding portion of the housing 90 may be enclosed or provided with an outer housing 150 as illustrated in FIG. 9 . The outer housing 150 covers at least the aperture 91. The outer housing 150 also covers at least a portion or all of the rod-shaped and elongated indicating portion 142 of the fill level indicator 135. The outer housing 150 may cover the entire L-shaped rod 140 in the longitudinal direction and in any available position of the fill level indicator 135 relative to the housing 90 or the body 10.

[0217] The outer housing 150 may further include a transparent portion 152. The transparent portion 152 may include a transparent window in the outer housing 150. All or only a portion of the elongated indicator portion 142 is discernible in the transparent portion 152 of the outer housing 150. One of the indicator portion 142 and the transparent portion 152 is or may be provided with a scale, while the other of the indicator portion 142 and the transparent portion 152 is provided with a pointer pointing to the scale.

[0218] The outer housing 150 may be opaque at least in the region where it covers the elongated aperture 91 of the housing 90 or body 10. In this way, the inner structure or interior of the dose setting mechanism 9 and / or drive mechanism 8 may remain covered and not visible from outside the housing 90 or outer housing 150.

[0219] Reference numerals list

[0220] 1 Injection device

[0221] 2 Distal direction

[0222] 3 Proximal direction

[0223] 4 Dose escalation direction

[0224] 5 Dose reduction direction

[0225] 6 Cartridges

[0226] 7. Stopper

[0227] 8 Driving mechanism

[0228] 9 Dose setting mechanism

[0229] 10 Second component

[0230] 11 Trigger

[0231] 12 Dose dial

[0232] 13 Dosage Window

[0233] 14 Cartridge holder

[0234] 15 Injection needle

[0235] 16 Inner needle cap

[0236] 17 Outer needle cap

[0237] 18 Protective cap

[0238] 19 Protrusion

[0239] 20 Piston rod

[0240] 21 Bearing

[0241] 22 First thread

[0242] 23 Pressure foot

[0243] 24 Second thread

[0244] 25 Cylinder

[0245] 26 Seals

[0246] 28 threaded socket

[0247] 29 Stop feature

[0248] 30 First Component

[0249] 31 Threaded section

[0250] 32 Stopper

[0251] 33 Stopper

[0252] 34 Base part

[0253] 35 Fill level indicator

[0254] 36 Indication section

[0255] 37 Pointer

[0256] 38 thread segment

[0257] 39 Protrusion

[0258] 40 Spring

[0259] 50 Dose Tracker

[0260] 51 Tracking stop feature

[0261] 60 adapter

[0262] 62 Inserts

[0263] 64 handles

[0264] 80 Number Sleeve

[0265] 81 Grooves

[0266] 90 Shell

[0267] 91 Orifice

[0268] 92 Window

[0269] 93 longitudinal end

[0270] 94 scale

[0271] 95 longitudinal end

[0272] 99 Depression

[0273] 100 Starting position

[0274] 101 Middle position

[0275] 102 End position

[0276] 134 Base part

[0277] 135 Fill level indicator

[0278] 138 Threaded section

[0279] 139 Protrusion

[0280] 140 bars

[0281] 141 Bridge Section

[0282] 142 Indication section

[0283] 144 Stop surface

[0284] 150 External housing

[0285] 152 Transparent part

Claims

1. An injection device for setting and injecting a dose of a medicament, the injection device comprising: - an elongated housing (90) extending in a longitudinal direction, said elongated housing (90) being configured to accommodate the cartridge (6), - a first member (30) movably arranged inside the elongated housing (90) for setting the dose, and - a second member, a piston rod (20) configured to be advanced in a longitudinal distal direction (2) and operable to apply a distally directed pressure to the bung (7) of the cartridge (6) for expelling the dose, - wherein during one of setting of the dose and expelling of the dose, the first member (30) is rotatable relative to the second member, and wherein during the other of setting of the dose and expelling of the dose, the first member (30) is rotationally locked to the second member, a filling level indicator (35; 135) which is threadedly engaged with one of the first member (30) and the second member, and wherein the filling level indicator (35; 135) is rotationally locked and longitudinally slidably engaged with the other of the first member (30) and the second member, - wherein the filling level indicator (35; 135) is movable in a longitudinal direction relative to the first component (30) and / or relative to the second component at least from a starting position (100) to an end position (102), and - wherein the housing (90) comprises an elongated opening (91) extending in the longitudinal direction, and wherein when the fill level indicator (35; 135) is in the starting position (100), at least an indicating portion (36) of the fill level indicator is visible through the elongated opening (91) and from the outside of the housing (90).

2. An injection device according to claim 1, wherein when the first member (30) rotates relative to the second member along a first direction, the filling level indicator (35; 135) moves in a longitudinal direction toward an end position relative to the first member (30) and / or relative to the second member.

3. An injection device according to claim 1 or 2, wherein when the first member (30) rotates relative to the second member along the second direction, the filling level indicator (35; 135) moves in a longitudinal direction toward a starting position relative to the first member (30) and / or relative to the second member.

4. Injection device according to any one of claims 1-2, wherein when the filling level indicator (35; 135) is in the end position (102), the filling level indicator (35; 135) is visible from the outside of the housing (90).

5. Injection device according to any one of claims 1-2, wherein the filling level indicator (35; 135) is visible from the outside of the housing (90) in any position (101) between the starting position (100) and the end position (102).

6. An injection device according to any one of claims 1-2, wherein the longitudinal displacement of the filling level indicator (35; 135) towards the end position in one of the dose setting process and the dose expulsion process is proportional to the distal advancement movement of the piston rod (20) during the dose expulsion process.

7. The injection device according to any one of claims 1-2, wherein one of the first member (30) and the second member comprises a first stopper (32) and a second stopper (33), wherein the first stopper (32) and the second stopper (33) are separated from each other along the longitudinal direction.

8. An injection device according to claim 7, wherein when in the end position (102), the fill level indicator (35; 135) engages the second stop member (33), and wherein when the fill level indicator (35; 135) engages with the second stop member (33), the fill level indicator (35; 135) is operable to prevent further movement of the first member (30) relative to the second member at least in one direction of movement.

9. The injection device according to claim 1 or 2, wherein the elongated orifice (91) is covered or closed by a transparent window.

10. Injection device according to any of the preceding claims 1 to 2, wherein at least an indicating portion of the fill level indicator is located outside the housing (90).

11. Injection device according to claim 10, wherein the filling level indicator comprises an L-shaped rod (140), the L-shaped rod comprising the indicating portion and a bridge portion (141), wherein the bridge portion (141) extends through the orifice (91).

12. An injection device according to claim 10, further comprising an external shell (150), which covers or surrounds at least a part of the shell (90) in the area of ​​the fill level indicator, wherein the external shell (150) comprises a transparent window overlapping at least the indicating part of the fill level indicator.

13. An injection device according to any one of claims 1-2, wherein the housing (90) comprises a body (10) forming a proximal end of the housing (90) and a cartridge holder (14) forming a distal end of the injection device, wherein the filling level indicator (35; 135) is located at the distal end of the body (10) or near the distal end of the body (10).

14. The injection device according to any one of claims 1-2, further comprising a protective cap (18), which is configured to surround and protect a distal section of the housing (90), wherein the fill level indicator (35; 135) is positioned to be longitudinally offset from the protective cap (18).

15. The injection device according to any one of claims 1-2, wherein the housing (90) comprises a cartridge holder (14) configured to accommodate the cartridge (6), wherein the cartridge holder (14) is opaque.

16. An injection device according to any one of claims 1-2, wherein the housing (90) comprises a scale (94) extending along the elongated aperture (91), and wherein the indicating portion comprises a pointer (37; 137) pointing to the scale (94).

17. An injection device according to any one of claims 1-2, wherein the filling level indicator (35; 135) includes at least one of a radial protrusion or a radial recess and a threaded section (38; 138), wherein the threaded section (38; 138) engages with a correspondingly shaped reverse threaded section (31) of one of the first member (30) and the second member, and wherein at least one of the radial protrusion or the radial recess (39; 139) engages longitudinally in a radial recess or a radial protrusion of a corresponding shape of the other of the first member (30) and the second member.

18. An injection device according to any one of claims 1-2, wherein the first member (30) is movable relative to the second member only during one of setting of the dose and dispensing of the dose.

19. The injection device according to any one of claims 1-2, further comprising the cartridge (6) filled with the medicament and arranged inside the elongated housing (90).

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