Injection device having a fill level indicator - Patents.com

Abstract

The present disclosure relates to an injection device for setting and injecting a dose of a medication, the injection device comprising: an elongated housing (90) extending along a longitudinal direction and configured to accommodate a cartridge (6), a first member (30) and a second member (10) movably disposed within the elongated housing (90) for setting a dose, and a piston rod (20) configured to advance in a distal longitudinal direction (2) and operable to apply distal pressure on a bung (7) of the cartridge (6) to expel a dose, wherein the first member (30) is rotatable relative to the second member (10) during one of setting the dose and expelling the dose, and the first member (30) is non-rotatably locked relative to the second member (10) during the other of setting the dose and expelling the dose; a fill level indicator (35; 135) threadedly engaged with one of the first member (30) and the second member (10), and non-rotatably locked relative to the other of the first member (30) and the second member (10) and longitudinally slidably engaged, - the fill level indicator (35; 135) longitudinally movable relative to the first member (30) and / or relative to the second member (10) from at least a start position (100) to an end position (102), - the fill level indicator (35; 135) visible from outside the housing (90) when the fill level indicator (35; 135) is in the start position (100).

Description

[Technical field]

[0001] The present disclosure relates to the field of injection devices, and in particular to portable injection devices such as pen injectors. [Background technology]

[0002] Drug delivery devices for setting and dispensing single or multiple doses of liquid medication are known per se in the art. Typically, such devices have a purpose substantially similar to that of a conventional syringe.

[0003] Drug delivery devices such as pen injectors must meet several user-specific requirements. For example, a patient may be physically frail and may have impaired eyesight due to a chronic disease such as diabetes that the patient suffers from. Therefore, a suitable drug delivery device specifically intended for home drug treatment must be robust in construction and easy to use. Furthermore, the operation and general handling of the device and its components should be straightforward and easily understandable. Such an injection device should provide for the setting and subsequent dispensing of doses of a variable size drug. Furthermore, the dose setting and dose dispensing procedures must be easy to operate and clear.

[0004] Typically, such devices include a housing or a specific cartridge holder adapted to receive a cartridge at least partially filled with the medicament to be dispensed. The device further includes a drive mechanism, typically having a piston rod displaceable into operative engagement with a bung or piston of the cartridge, by means of which the bung or piston of the cartridge can be displaced in a distal or dispensing direction and thus expel a predetermined amount of medicament through a piercing assembly, e.g. in the form of a syringe needle, which is releasably coupled with a distal end section of the housing of the drug delivery device.

[0005] The medicament dispensed by the drug delivery device can be provided and contained in a multi-dose cartridge. Such cartridges typically include a vitreous barrel sealed distally by a pierceable seal and further sealed proximally by a bung. In a reusable drug delivery device, an empty cartridge can be replaced with a new one. In contrast, a disposable drug delivery device is to be completely discarded once the medicament in the cartridge has been dispensed or used up.

[0006] In some drug delivery devices, such as pen injection devices, the user must set equal or variable size doses by rotating a dose dial clockwise or in dose increments relative to the body or housing of the injection device. To inject and expel a dose of liquid medication, the user must depress a trigger or dose button distally and thus toward the body or housing of the injection device. Typically, the user uses his or her thumb to apply distal pressure to the dose dial and the dose button located at the proximal end of the dose dial sleeve while holding the housing of the injection device with the remaining fingers of the same hand.

[0007] For example, a pen-type injection device, such as that disclosed in US Pat. No. 5,999,366, includes a final dose limiting mechanism. The final dose limiting mechanism may include a final dose limiter configured to prevent the setting of a dose that exceeds the amount of drug in the cartridge. To this end, the drive sleeve of the drive mechanism may be provided with a first flange and a second flange having an intermediate thread therebetween. A nut may be provided disposed between the first flange and the second flange and hooked to the housing by a splined connection means.

[0008] Such a final dose stop limiting mechanism is effective to abort the dose setting procedure if the user attempts to set a dose that exceeds the remaining amount of drug provided in the cartridge.

[0009] Portable injection devices, such as injection pens, typically include a transparent cartridge holder configured to receive and / or house a cartridge filled with a medication, thereby enabling visual inspection of the medication located within the cartridge. Additionally, a transparent cartridge holder also enables visual inspection of the medication when the cartridge housed within the cartridge holder is also transparent or translucent.

[0010] A patient or person attempting to set a volume of a given size may have difficulty estimating or accurately determining whether the amount of drug provided in the cartridge is large enough or sufficient for setting the required dose. The fill level of the cartridge may be difficult to visually determine or inspect. Furthermore, cartridges, which may be made from vitreous materials, typically include a tubular shape, which inherently results in scattering and / or deflection of light, making it difficult to accurately determine the amount of drug inside the cartridge. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] WO2004 / 078241A1 Summary of the Invention [Problem to be solved by the invention]

[0012] In view of this, it is desirable to provide an injection device with a fill level indicator operable to visually indicate to a person or patient the remaining amount or remaining fill of a cartridge located therein. 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 fill level indicator operable to visually indicate the future fill 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 improve patient safety and overall ease of use, as well as the overall acceptability of the portable injection device. [Means for solving the problem]

[0013] In one embodiment, the present disclosure relates to an injection device for setting and injecting a dose of a medicament. The injection device includes an elongated housing, e.g., tubular in shape, extending along a longitudinal direction. The elongated housing is configured to accommodate a cartridge. The cartridge preferably includes a barrel filled with the medicament and is sealed in a proximal longitudinal direction by a bung. The bung is preferably displaceable relative to the barrel for ejection of the medicament.

[0014] The injection device further includes a first member movably disposed within the elongated housing for setting a dose of the medicament. The injection device further includes a second member. The second member is a separate member and distinct from the first member.

[0015] The injection device further comprises a piston rod configured to advance in a longitudinal distal direction, the piston rod being operable to exert a distal pressure on the bung of the cartridge to eject the dose, typically driven by a drive mechanism of the injection device during ejection for ejection of a previously set dose of medicament.

[0016] During one of dose setting and dose ejection, the first member is rotatable relative to the second member. During the other of dose setting and dose ejection, the first member is non-rotatably locked relative to the second member. The first and second members may be engaged in a longitudinal or axial direction. The first member may be immobile and / or positionally locked relative to the second member in a longitudinal or axial direction.

[0017] In some examples, only one of the first and second members may be movable during and / or for setting the dose, while the other of the first and second members is stationary relative to the housing. During and / or for ejection of the dose, the first and second members are immovable relative to each other. Here, the first and second members may both be immovable relative to the housing, or both the first and second members may undergo a common or combined movement relative to the housing.

[0018] In some other examples, the first member and the second member are immovable relative to each other during and / or for setting the dose. Here, the first member and the second member may both be immovable relative to the housing, or both the first member and the second member may undergo a common or combined movement relative to the housing. Then, for and / or during ejection of the dose, at least one of the first member and the second member becomes movable relative to the other of the first member and the second member.

[0019] The injection device further comprises a fill level indicator threadedly engaged with one of the first and second members. The fill level indicator is non-rotatably locked and longitudinally slidably engaged with the other of the first and second members. The fill level indicator can be threadedly engaged with the first member, and the fill level indicator can be in a so-called splined engagement with the second member. Rotation of the first member relative to the second member then causes longitudinal displacement of the fill level indicator relative to the first and second members.

[0020] The fill level indicator is longitudinally movable relative to the first member and / or relative to the second member at least from a start position to an end position. When the first member rotates relative to the second member, the fill level indicator moves longitudinally relative to the first member and / or relative to the second member towards the end position. Typically, the start position and the end position are opposite end positions of the fill level indicator.

[0021] In particular, when the first member rotates relative to the second member along a first direction, e.g. a dose increment direction during dose setting or a dose decrement direction during dose ejection, the fill level indicator moves longitudinally relative to the first member and / or relative to the second member towards an end position.

[0022] In some examples, when the first member rotates relative to the second member in a second direction, e.g. along the dose decrement direction during dose setting, i.e. when the already set dose is too large, the fill level indicator moves longitudinally relative to the first member and / or relative to the second member towards the start position and the previously set dose undergoes a correction before dispensing or expelling the dose.

[0023] The fill level indicator is visible from outside the housing when the fill level indicator is in the starting position.

[0024] Typically, the longitudinal position of the fill level indicator relative to the first and / or second member directly correlates with the longitudinal position of the piston rod relative to the elongated housing. When the fill level indicator is in the start position, the piston rod is in an initial position, which typically coincides with the proximal end position. When the fill level indicator is in the end position, the piston rod is in a final or end position, which typically coincides with the distal end position. In examples where 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 located after dispensing or expelling the actually set dose. In examples where the first member is rotatable relative to the second member only during and / or for dose expelling, the instantaneous longitudinal position of the fill level indicator relative to the first and / or second member directly and immediately indicates the longitudinal position of the piston rod relative to the housing or cartridge.

[0025] In either 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. Because the piston rod abuts 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 is directly indicative of the position of the bung relative to the barrel of the cartridge and thus of the amount of medicament located within the cartridge.

[0026] By making the fill level indicator visible from the outside of the housing when placed or located in the start position, an indication is given to the user that the cartridge has not been used previously and that the entirety of the medicament originally provided in the cartridge is still present in the cartridge and is therefore still available for dose delivery. Thus, when the fill level indicator is in the start position, this provides a clear and unambiguous indication to a user or patient of the injection device that the injection device has not been used previously for dose delivery.

[0027] By providing a fill level indicator in engagement with the first and second members and having the fill level indicator visible from outside the housing, it is possible to provide visual feedback to a user or patient using the injection device that the cartridge is fully filled and that the injection device is in an initial configuration or unused state. Apart from an optional priming shot or step when in the starting position, the fill level indicator indicates that the initial fill amount of the cartridge is still available.

[0028] Typically, the fill level indicator may be provided in any suitable portion of the housing of the injection device. Typically, the fill level indicator may be provided at or near the distal end of a proximal housing component, also referred to as the body of the housing. The body of the housing is typically configured to receive or house a drive mechanism of the injection device. The housing further includes a cartridge holder configured to receive or house a cartridge filled with a medicament. In a typical configuration, the distal end of the cartridge holder is configured to hold a removable 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 may be interconnected or fixed to the distal end of the body.

[0029] At the proximal end of the body, a dose dial and / or an injection button operable to set and / or dispense or expel, for example, variable size doses, may be provided. The fill level indicator may be located at or near the distal end of the body, the body forming or constituting the proximal end of the housing of the injection device. The fill level indicator may typically be located longitudinally offset from the cartridge holder, or at least a protective cap covering the distal end of the cartridge holder. By providing the fill level indicator on a proximal housing component, 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, may be permanently accessed from outside the housing, without the need to remove or dismantle the protective cap from the injection device.

[0030] Typically, when the filling level indicator is in the starting position, the piston rod is in a proximal end configuration or position. In the proximal end configuration or position, the piston rod can be in axial abutment with the bung of the cartridge or the piston rod can be located near the bung of the cartridge with a well-defined gap between them. In the latter case, the injection device must undergo a priming procedure before the first injection can be performed. During the priming procedure, the piston rod advances distally until it engages with the bung. This initial, but small-sized distal movement of the piston rod may only optionally be reflected in a respective change in the position of the filling level indicator relative to the housing. Also, the filling level indicator can reach the starting position when the priming procedure is completed.

[0031] When the injection device is repeatedly used to set and expel a dose of medicament, the piston rod continuously advances in the distal longitudinal direction. The more the piston rod advances or moves in the distal longitudinal direction, the further the fill level indicator advances towards the end position. When the piston rod reaches a distal end position within the injection device, the fill level indicator also reaches an end position relative to the housing.

[0032] Typically, the start position of the fill level indicator is a longitudinal start 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 dose setting or dose ejection, the fill level indicator moves towards the end position. In some examples, the fill level indicator can slide relative to the second member along the longitudinal direction. The second member can provide a sliding track for the fill level indicator. During repeated dose setting procedures or repeated dose ejection procedures, the fill level indicator can slide continuously from the start position towards the end position along the sliding track provided by the housing. Typically, the start 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.

[0033] According to a further example, the fill level indicator is visible from outside the housing when the fill level indicator is in the end position. In this way, the fill level indicator is operable to visually indicate to a user or patient that the cartridge is substantially empty or almost empty and that the remaining amount of medicament remaining in the cartridge is or will be too small or insufficient to set and / or expel a further dose of medicament.

[0034] In this configuration, when the fill level indicator reaches its end position relative to the housing, this provides a clear visual indication to the user or patient that the injection device can no longer be used to set and dispense a dose of medication.

[0035] According to another example, the fill level indicator is visible from outside the housing at any position between the start and end positions 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 dose ejection towards the end position is proportional to the distal forward movement of the piston rod during the dose ejection or dose dispensing procedure. In this way, when the fill level indicator is located, for example, halfway between the start and end positions, this immediately indicates to the user or patient that half of the initial fill of medicament is still located in the cartridge.

[0036] The proportional mechanical coupling between the fill level indicator, the first member and the second member is particularly beneficial in providing a user with linear visual feedback regarding the instantaneous fill level of the cartridge located inside the injection device.

[0037] Typically, having a fill level indicator visible from outside the housing at any position between the start and end positions provides fairly direct tracking of the cumulative size of the doses already set and / or dispensed or expelled by the injection device.

[0038] According to a further example, the first member and the second member include a first stop and a second stop. Thus, one of the first member and the second member can include both the first stop and the second stop. Alternatively, one of the first member and the second member includes the first stop and the other of the first member and the second member includes the second stop.

[0039] The first stop and the second stop are separated from each other along the longitudinal direction. Typically, the first stop defines a start position of the fill level indicator. Typically, the second stop defines an end position of the fill level indicator. When in the start position, the fill level indicator can engage with the first stop. When in the start position, the fill level indicator can abut with the first stop. When in the start position, the fill level indicator can abut with the first stop in at least one of an axial direction or a tangential direction.

[0040] In a further example, the fill level indicator engages a second stop when the end position is reached or at the end position, wherein the fill level indicator is operable to prevent further movement of the first member relative to the second member in at least one direction, e.g. a first direction of movement, when the fill level indicator engages or abuts the second stop, wherein the second stop forms or provides a final dose stop effective to prevent setting of a dose that exceeds the remaining amount of medicament provided in the cartridge.

[0041] 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 the fill level indicator is in the end position, it typically engages the second stop in at least one of an axial or tangential direction.

[0042] In this way, when the first member undergoes a rotational movement relative to the second member, the fill level indicator starts to move along a helical path relative to the one of the first and second members with which the fill level indicator is threadedly engaged. At the same time, the fill level indicator starts to slide along a sliding track provided by the other of the first and second members. When one of the start and end positions is reached or when in one of the start and end positions, the fill level indicator engages with the respective stop. When the start position is reached, the fill level indicator engages, e.g. abuts, with the first stop. When the end position is reached, the fill level indicator will abut, e.g. engage, with the second stop.

[0043] At least one of the first and second stops is operable to prevent further displacement of the fill level indicator past the first or second stop, respectively. The fill level indicator is non-rotatably locked relative to one of the first and second members, such that circumferential, tangential or longitudinal abutment between the fill level indicator and one of the first and second stops of one of the first and second members immediately blocks any further rotation of the first member relative to the second member, e.g. along a first direction. The first direction may be a dose increment direction, when the first and second members undergo relative movement only during dose setting.

[0044] In this way, the fill level indicator can be operable not only to visualize the instantaneous position of the piston rod, but also to prevent the setting of a dose that exceeds the amount of drug provided in the cartridge.

[0045] In some examples, the second member is a housing component, e.g. the body of an elongated housing, and the first member is one of the dose setting member and the dose ejection member, wherein the dose setting member undergoes rotational movement relative to the housing component or body only during dose setting, and the dose ejection member undergoes rotational movement relative to the housing component or body only during dose ejection.

[0046] In some examples, the first member comprises a sleeve-like or tubular shape. Typically, the first member, when implemented as a dose setting member or a dose ejection member, is disposed within a second member, which may comprise a hollow body of tubular shape. The first member and the second member may be coaxially arranged in a telescopic or spiral manner. The outer surface of the first member may engage with an inner portion of the fill level indicator. The outwardly facing portion of the fill level indicator then typically engages with an inwardly facing portion of the second member, and thus engages with the body.

[0047] When the first member is in threaded engagement with the fill level indicator, the second member is splined with the fill level indicator. During dose setting, the first member rotates relative to the second member, thereby resulting in a longitudinal movement of the fill level indicator towards the end position when the first member is rotated relative to the second member along a first direction. During dose ejection, the first member is non-rotatably locked relative to the second member, for example by a clutch. During dose ejection, the first member may then be stationary relative to the housing or body or may undergo a purely longitudinal, non-rotational sliding movement. In the latter case, both the fill level indicator and the first member may undergo a common and / or combined sliding movement relative to the housing.

[0048] According to another example, the housing of the injection device further comprises an elongated aperture extending along the longitudinal direction. Furthermore, the fill level indicator comprises an indicia portion. The indicia portion is visible through the elongated aperture of the housing. The scale typically extends along a sliding track or displacement path of the fill level indicator, starting at a start position and ending at an end position. In some examples, the elongated aperture is provided directly in the first member.

[0049] In a typical example, the extension of the aperture is as long as the distance from the start position to the end position of the fill level indicator. The total longitudinal extension of the aperture may indicate and 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 indicated portion of the fill level indicator relative to the longitudinal axis located opposite the elongated aperture directly indicates the amount of medicament provided in the cartridge in relation to the initial or total fill volume of the cartridge.

[0050] In a further example, the elongated aperture of the housing includes a first longitudinal end and further includes an oppositely located second longitudinal end. When the fill level indicator is in the start position, the indicia of the fill level indicator can be located near the first longitudinal end of the elongated aperture or can abut, for example longitudinally and thus axially, with the first longitudinal end. When the fill level indicator is in the end position, the respective indicia of the fill level indicator can be located near the second longitudinal end of the elongated aperture. The indicia can overlap the second longitudinal end and / or abut, for example axially, with the second longitudinal end of the aperture.

[0051] In this way, at least the second longitudinal end of the aperture can be provided with a stop to engage with the longitudinally displaceable fill level indicator. The fill level indicator can axially engage, i.e. axially abut, with the second longitudinal end of the elongated aperture when the second end position is reached. In this way, the second longitudinal end of the elongated aperture can act as a second stop as explained above. The second longitudinal end can provide a final dose stop configured to block any further longitudinal movement of the fill level indicator beyond the end position relative to the housing.

[0052] According to a further example, the elongated aperture is covered or closed by a transparent window. The elongated aperture can be completely closed or filled with a transparent window. In this way, the interior of the housing of the injection device can be effectively protected against the ingress of moisture and / or particles. Furthermore, manual manipulation of the filling level indicator can be effectively prevented by the transparent window. The transparent window covering the elongated aperture can completely cover and / or encapsulate the filling level indicator located below.

[0053] According to a further example, the housing comprises an elongated aperture extending along the longitudinal direction of the elongated housing, where, in contrast to the examples described above, at least the indication part of the fill level indicator is located outside the housing, whereas the remaining part or base part of the fill level indicator is located inside the housing, in particular in the area between the interior of the elongated housing and the exterior of one of the first or second members.

[0054] By providing at least a dedicated part of the filling level indicator on the outside of the housing, the visibility and size of the filling level indicator, in particular the visibility and size of the indication part of the filling level indicator, can be increased compared to the example where the filling level indicator is located completely inside the housing. Furthermore, by locating at least a part of the filling level indicator on or outside the housing, tactile feedback regarding the instantaneous filling level of the cartridge can also be provided to the user. The position of the indication part of the filling level indicator can be tactilely detected and palpable. In addition, by providing at least the indication part of the filling level indicator on or outside the housing, the indication part operable to indicate the instantaneous longitudinal position of the piston rod relative to the housing can be spatially separated from the base part of the filling level indicator at least in one of the longitudinal or circumferential directions. The base part mechanically engages both the first part and the inner sidewall part of, for example, the second part of, for example, the elongated housing.

[0055] According to a further example, the filling level indicator comprises an L-shaped rod, the L-shaped rod comprising an indicator portion and further comprising a bridging portion, wherein the bridging portion extends through the aperture and is connected 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 aperture comprises a radial extension greater than a thickness of the side wall of the elongated housing. In this way, the L-shaped rod of the filling level indicator, in particular the indicator portion, can comprise one of an annular circumferentially extending structure and a longitudinally extending rod-shaped structure provided on the exterior of the housing.

[0056] Due to the elongated or longitudinally extending indicator portion, the L-shaped rod enables an arrangement of the fill level indicator where at least the indicator portion of the fill level indicator is axially or longitudinally offset from a base portion of the fill level indicator. In this way, the portion of the fill level indicator visually perceptible from outside the housing can be located axially and / or circumferentially offset in the housing from the first member and / or from the aperture.

[0057] In this way, the fill level can be indicated at almost any or desired location on the outer surface of the housing of the injection device, and the overall design of the injection device can therefore be adapted and designed to meet given user requirements.

[0058] According to a further example, the injection device includes an outer housing that covers or encloses at least a portion of the housing in the area of ​​the fill level indicator. The outer housing includes a transparent window that overlaps at least the marking portion of the fill level indicator. The outer housing is particularly intended for examples where the aperture in the housing or inner housing of the injection device does not have a transparent window and where the bridging portion of the fill level indicator extends through the aperture of the housing or inner housing. The outer housing can effectively close or encapsulate the aperture of the inner housing through which the fill level indicator extends, thus protecting against the ingress of particles or moisture.

[0059] According to another example, the housing of the injection device includes a cartridge holder configured to receive the cartridge. In this particular example, the cartridge holder is translucent. The cartridge holder is translucent at least in terms of the visible spectrum of electromagnetic radiation, e.g. visible light. In another example, the cartridge holder is translucent at least for a dedicated spectrum of electromagnetic radiation. The cartridge holder can be translucent for ultraviolet radiation and / or for infrared radiation.

[0060] Apart from a through hole in the distal face for receiving the proximal tip of the injection needle, the cartridge holder has no apertures or through holes in the side walls, and in this way is configured to completely enclose the cartridge and protect it against external electromagnetic radiation.

[0061] Providing a translucent cartridge holder is advantageous in protecting the medicament located therein against the respective electromagnetic radiation, in this way the cartridge holder serves to protect the cartridge and medicament located therein against adverse effects resulting from irradiation by one of the electromagnetic radiations in the visible, ultraviolet and / or infrared spectral ranges.

[0062] Some medications are quite sensitive to electromagnetic radiation, where a translucent and / or opaque cartridge holder is advantageous to protect the medication against such adverse environmental effects.

[0063] The fill level indicator may obviate the need for visual inspection of the cartridge and / or the medicament located therein. Thus, implementation of the fill level indicator allows for the use of a cartridge holder that is substantially translucent to at least one of infrared radiation, light within the visible spectrum, and UV radiation.

[0064] According to another example, the housing includes a scale extending along an elongated aperture of the housing. The indicia portion of the fill level indicator includes a pointer pointing towards the scale. The scale typically includes a number of marks or symbols indicating the longitudinal position of the piston rod relative to the housing and thus the remaining amount of medicament remaining in the cartridge. The scale may include a number of graduations or marks. Such graduations or marks may be equally spaced longitudinally along the longitudinal extension of the scale.

[0065] The scale may be provided with symbols or numbers to indicate the amount of drug still available in the cartridge.

[0066] Typically, the pointer comprises a sharp tip pointing towards the scale. The pointer may be provided as a further mark on the outer surface of the marking portion of the fill level indicator. The scale may be provided on the outside of the housing. The scale may be divided into a number of longitudinally adjacently located sections. Each of the sections may be characteristic of a particular configuration of the injection device. A section adjacent to a first longitudinal end of the aperture may indicate that the cartridge is nearly or substantially completely filled with medicament. A further section located at a second longitudinal end of the aperture may 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.

[0067] Multiple and / or adjacently located sections of the scale may be given different colors, thereby allowing a fairly intuitive and comprehensive understanding of the instantaneous configuration of the injection device.

[0068] According to another example, the filling level indicator comprises a threaded section and at least one of a radial protrusion or a radial recess. The threaded section is an externally threaded section or an internally threaded section. The threaded section is threadedly engaged with a correspondingly shaped mating threaded section of one of the first and second members. At least one of the radial protrusions or radial recesses of the filling level indicator is in longitudinal sliding engagement with a correspondingly shaped radial recess or radial protrusion of the other of the first and second members. The mutually corresponding recesses and protrusions of one of the first or second members and the filling level indicator enable longitudinal sliding movement of the filling level indicator relative to the respective first or second member provided with a correspondingly shaped radial recess or radial protrusion.

[0069] At least one radial recess or radial protrusion on the fill level indicator may be provided which engages and / or mates with a correspondingly shaped radial protrusion or recess on one of the first and second members. A number of radial recesses or protrusions on the fill level indicator may be provided which engage and / or mate with a corresponding number of correspondingly shaped radial protrusions and / or recesses on one of the first and second members. In this way, a double, triple or even quadruple sliding engagement and non-rotatably locked engagement between the fill level indicator and one of the first and second members may be provided, which results in a fairly robust and reliable implementation of the fill level indicator.

[0070] In one example, the fill level indicator comprises an internal thread engaged with the external thread of the second member. The fill level indicator further comprises a radially outwardly extending protrusion engaged with a correspondingly shaped radially longitudinally extending recess or groove provided on the internal surface of the first member. In this way, when the second member, for example embodied as a dose setting sleeve or drive sleeve of the drive mechanism, is rotated relative to the housing, the fill level indicator slides along the longitudinal recess or groove of the first member. Here, the first member can be embodied as, for example, a tubular shaped housing or body. The first member can also be embodied as an insert rigidly attached and / or fixed to or inside the body of the housing. Here, the longitudinally extending recess or groove of the first member provides a sliding track extending from a start position of the fill level indicator towards and / or to an end position of the fill level indicator relative to the first member, for example embodied as a body or housing.

[0071] In another example, the fill level indicator comprises an external thread engaged with a correspondingly shaped internal thread of the first member. Here, the fill level indicator comprises one of a radially inwardly extending protrusion or respective recess that engages with a correspondingly shaped recess or radially extending protrusion of the second member. For example, the second member embodied as a dose setting sleeve or a drive sleeve can comprise one of an elongated longitudinally extending groove in sliding engagement with a radially extending protrusion of the fill level indicator. Alternatively, it is the fill level indicator that comprises an elongated groove or an elongated radial recess engaged with a correspondingly shaped radial protrusion of the second member.

[0072] The radial projection is one of a radially outwardly extending projection and a radially inwardly extending projection. The longitudinal recess is of a complementary shape to the radial projection. When the radial projection extends radially outwardly on the fill level indicator, the elongated recess is typically provided on an inner sidewall portion of the first member or the second member. When the radial projection extends radially inwardly on the fill level indicator, the elongated recess is typically provided on an outer sidewall portion of the first member or the second member.

[0073] In either case, when the second member is subjected to a rotational movement relative to the first member, the fill level indicator is subjected to a longitudinal displacement relative to the first member in a direction towards the end position.

[0074] When splined and thus in longitudinal sliding engagement with the second member, the fill level indicator comprises an arcuate or semicircular structure and thus may represent a half-split 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 is typically annular in shape. Here, the second member, for example embodied as a housing, body or housing component and including a longitudinally extending elongated aperture, provides a permanent visual survey of the longitudinal and / or axial position of the fill level indicator within the aperture of the second member and thus provides this from outside the housing.

[0075] According to a further example, the first member is non-rotatably locked relative to the housing during dispensing of a dose of medicament while the piston rod advances longitudinally distally relative to the housing. During dose dispensing or dose ejection, the first member can be immovable relative to the second member. The first member can be locked relative to the second member at least for rotational movement. The first member can also be locked relative to the second member for axial or longitudinal movement. The first member can be permanently locked axially relative to the second member, i.e., both during dose setting and dose dispensing or dose ejection.

[0076] In another example, the fill level indicator is exclusively displaceable only relative to at least one of the first member and the second member during dose setting. The fill level indicator can be displaceable relative to both the first member and the second member during and / or for dose setting. The fill level indicator can undergo a sliding movement relative to the second member during dose setting. The fill level indicator can undergo a rotational or helical movement relative to the first member during dose setting. When the dose is set, the fill level indicator and the first member are rotatable relative to each other. They may remain non-rotatable relative to each other when the dose is expelled, or may be non-rotatably locked relative to each other. In this way, when the fill level indicator is being moved along the sliding track 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 aperture indicates and / or represents the summarized dose previously set by the injection device.

[0077] When the fill level indicator is in the end position, the summarized set dose previously set by the injection device is typically equal to the initial drug amount in the cartridge.

[0078] The injection device typically includes a switchable clutch that is selectively engageable with the first member and the second member. Typically, when the switchable clutch is in one of a dose setting state and a dose ejection state, the first member is rotatable relative to the second member. When the clutch is switched to the other of the dose setting state and the dose ejection state, the first member is non-rotatably locked and / or in a locked state relative to the second member. In some examples, when the clutch is in the dose setting state, the first member is rotatable relative to the second member. When the clutch is in the dose ejection state, the first member is non-rotatably locked relative to the second member.

[0079] In some other examples, the first member is rotatable relative to the second member when the clutch is in the dose ejection state, and the first member is non-rotatably locked relative to the second member when the clutch is in the dose setting state.

[0080] Generally, the scope of the present disclosure is defined by the contents of the claims. The injection device is not limited to a particular embodiment or example, but includes any combination of elements of different embodiments or examples. Thus, the present disclosure covers any combination of the claims and any technically feasible combination of the disclosed configurations with respect to the different examples or embodiments.

[0081] In this context, the term "distal" or "distal end" refers to the end of the injection device that faces towards the injection site of a person or animal. The term "proximal" or "proximal end" refers to the opposite end of the injection device that is furthest away from the injection site of a person or animal.

[0082] The term "drug" or "medicament" as used herein means a pharmaceutical preparation containing at least one pharma- ceutical active compound; wherein in one embodiment the pharma- ceutical active compound has a molecular weight of up to 1500 Da and / or is a peptide, a protein, a polysaccharide, a vaccine, DNA, RNA, an enzyme, an antibody or a fragment thereof, a hormone, or an oligonucleotide, or a mixture of the abovementioned pharma-ceutical active compounds, wherein in a further embodiment the pharma- ceutically active compound is useful for the treatment and / or prophylaxis of diabetes or complications associated with diabetes, such as diabetic retinopathy, thromboembolic disorders, such as deep vein thromboembolism or pulmonary thromboembolism, acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and / or rheumatoid arthritis, Wherein in a further embodiment the pharma- ceutically active compound comprises at least one peptide for the treatment and / or prevention of diabetes or complications associated with diabetes, such as diabetic retinopathy, Wherein, in a further embodiment, the pharma- ceutical active compound comprises at least one human insulin or a human insulin analog or derivative, a 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.

[0083] Insulin analogues 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 in position B28 is replaced by Asp, Lys, Leu, Val or Ala and in which the Lys in position B29 may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

[0084] Insulin derivatives include, 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-myristoyl-LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29Lys B30 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.

[0085] Exendin-4 means, for example, exendin-4(1-39), a peptide with the 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.

[0086] Exendin-4 derivatives include, for example, the compounds listed below: H-(Lys)4-desPro36,desPro37 Exendin-4(1-39)-NH2, H-(Lys)5-desPro36,desPro37 Exendin-4(1-39)-NH2, desPro36 exendin-4(1-39), desPro36[Asp28]exendin-4(1-39), desPro36[IsoAsp28]Exendin-4(1-39), desPro36[Met(O)14,Asp28]Exendin-4(1-39), desPro36[Met(O)14,IsoAsp28]Exendin-4(1-39), desPro36[Trp(O2)25,Asp28]exendin-4(1-39), desPro36[Trp(O2)25,IsoAsp28]Exendin-4(1-39), desPro36[Met(O)14 Trp(O2)25,Asp28]Exendin-4(1-39), desPro36[Met(O)14 Trp(O2)25,IsoAsp28]Exendin-4(1-39); or desPro36[Asp28]exendin-4(1-39), desPro36[IsoAsp28]Exendin-4(1-39), desPro36[Met(O)14,Asp28]Exendin-4(1-39), desPro36[Met(O)14,IsoAsp28]Exendin-4(1-39), desPro36[Trp(O2)25,Asp28]exendin-4(1-39), desPro36[Trp(O2)25,IsoAsp28]Exendin-4(1-39), desPro36[Met(O)14 Trp(O2)25,Asp28]Exendin-4(1-39), desPro36[Met(O)14 Trp(O2)25,IsoAsp28]Exendin-4(1-39), (wherein the group -Lys6-NH2 may be attached to the C-terminus of the exendin-4 derivative);

[0087] Or an exendin-4 derivative of the following sequence: desPro36 Exendin-4(1-39)-Lys6-NH2 (AVE0010), H-(Lys)6-desPro36[Asp28]Exendin-4(1-39)-Lys6-NH2, desAsp28Pro36,Pro37,Pro38 Exendin-4(1-39)-NH2, H-(Lys)6-desPro36,Pro38[Asp28]Exendin-4(1-39)-NH2, H-Asn-(Glu)5desPro36,Pro37,Pro38[Asp28]Exendin-4(1-39)-NH2, desPro36,Pro37,Pro38[Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-Asn-(Glu)5-desPro36,Pro37,Pro38[Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-(Lys)6-desPro36[Trp(O2)25,Asp28]Exendin-4(1-39)-Lys6-NH2, H-desAsp28Pro36,Pro37,Pro38[Trp(O2)25]Exendin-4(1-39)-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Trp(O2)25,Asp28]Exendin-4(1-39)-NH2, H-Asn-(Glu)5-desPro36,Pro37,Pro38[Trp(O2)25,Asp28]Exendin-4(1-39)-NH2, desPro36,Pro37,Pro38[Trp(O2)25,Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Trp(O2)25,Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-Asn-(Glu)5-desPro36,Pro37,Pro38[Trp(O2)25,Asp28]Exendin-4(1-39)-(Lys)6-NH2; H-(Lys)6-desPro36[Met(O)14,Asp28]Exendin-4(1-39)-Lys6-NH2, desMet(O)14 Asp28 Pro36,Pro37,Pro38 Exendin-4(1-39)-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Met(O)14,Asp28]Exendin-4(1-39)-NH2, H-Asn-(Glu)5-desPro36,Pro37,Pro38[Met(O)14,Asp28]Exendin-4(1-39)-NH2, desPro36,Pro37,Pro38[Met(O)14,Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Met(O)14,Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-Asn-(Glu)5 desPro36,Pro37,Pro38[Met(O)14,Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-Lys6-desPro36[Met(O)14,Trp(O2)25,Asp28]Exendin-4(1-39)-Lys6-NH2, H-desAsp28Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25]Exendin-4(1-39)-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Met(O)14,Asp28]Exendin-4(1-39)-NH2, H-Asn-(Glu)5-desPro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]Exendin-4(1-39)-NH2, desPro36, Pro37, Pro38[Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]Exendin-4(S1-39)-(Lys)6-NH2, H-Asn-(Glu)5-desPro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]Exendin-4(1-39)-(Lys)6-NH2; or a pharma- ceutically acceptable salt or solvate of any one of the aforementioned exendin-4 derivatives. is selected from.

[0088] Hormones are, for example, the pituitary or hypothalamic hormones or regulatory active peptides listed in the Rote Liste, 2008 edition, chapter 50, and their antagonists, such as gonadotropins (follitropin, lutropin, choriongonadotropin, menotropin), somatropines (somatropin), desmopressin, terlipressin, gonadorelin, triptorelin, leuprorelin, buserelin, nafarelin, goserelin.

[0089] The polysaccharides are, for example, glycosaminoglycans, hyaluronic acid, heparin, low molecular weight heparin or very low molecular weight heparin or derivatives thereof, or the above-mentioned polysaccharides in sulfated, e.g. polysulfated, form, and / or pharma- ceutically acceptable salts thereof. An example of a pharma-ceutically acceptable salt of polysulfated low molecular weight heparin is enoxaparin sodium.

[0090] Antibodies are globular plasma proteins (approximately 150 kDa) also known as immunoglobulins that share a common basic structure. They are glycoproteins because they have sugar chains attached to the amino acid residues. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only Ig units), and secretory antibodies can be dimers with two Ig units, such as IgA, tetramers with four Ig units, such as IgM in bony fish, or pentamers with five Ig units, such as IgM in mammals.

[0091] An Ig monomer is a "Y" shaped molecule consisting of four polypeptide chains; two identical heavy chains and two identical light chains joined by disulfide bonds between cysteine ​​residues. Each heavy chain is approximately 440 amino acids long, and each light chain is approximately 220 amino acids long. The heavy and light chains each contain intrachain disulfide bonds that stabilize these folded structures. Each chain is composed of structural domains called Ig domains. These domains contain 70-110 amino acids and are classified into different categories (e.g., variable or V, and constant or C) according to their size and function. They have a characteristic immunoglobulin fold in which two beta sheets create a "sandwich" shape held together by interactions between conserved cysteines and other charged amino acids.

[0092] There are five types of mammalian Ig heavy chains, designated α, δ, ε, γ, and μ. The type of heavy chain present defines the antibody's isotype, and these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively.

[0093] The different heavy chains differ in size and composition, with α and γ containing approximately 450 amino acids, δ containing approximately 500 amino acids, and μ and ε containing approximately 550 amino acids. Each heavy chain is composed of two regions: the constant region (C H ) and variable region (V H ) in a species. The constant region is essentially identical in all antibodies of the same isotype, but different in antibodies of different isotypes. Heavy chains gamma, alpha, and delta have constant regions made up of three tandem Ig domains and a hinge region to add flexibility, while heavy chains mu and epsilon have constant regions made up of four immunoglobulin domains. The variable region of the heavy chains differs 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 is made up of a single Ig domain.

[0094] In mammals, there are two types of immunoglobulin light chains, designated λ and κ. Light chains have two consecutive domains, one constant domain (CL) and one variable domain (VL). The approximate length of a light chain is 211-217 amino acids. Each antibody contains two light chains that are always identical, and for each antibody in a mammal, there is only one type of light chain, κ or λ.

[0095] Although the general structure of all antibodies is very similar, the unique properties of a given antibody are determined by the variable (V) region, as detailed above. More specifically, three variable loops for each light chain (VL) and three for each heavy chain (VH) are involved in binding to the antigen, i.e., its antigen specificity. These loops are called complementarity determining regions (CDRs). Since the CDRs from both the VH and VL domains contribute to the antigen binding site, it is the combination of the heavy and light chains that determines the final antigen specificity, not either one alone.

[0096] An "antibody fragment" contains at least one antigen-binding fragment as defined above and exhibits essentially the same function and specificity as the complete antibody from which it is derived. Limited proteolytic digestion with papain cleaves the Ig prototype into three fragments. Two identical amino-terminal fragments, each containing one complete L chain and approximately half of the H chain, are the antigen-binding fragments (Fab). The third fragment, which is comparable in size but contains the carboxyl termini at half of both heavy chains with interchain disulfide bonds, is the crystallizable fragment (Fc). Fc contains carbohydrate, complementary binding sites, and FcR sites. Limited pepsin digestion yields a single F(ab')2 fragment that contains both the Fab piece and the hinge region, including the HH interchain disulfide bond. F(ab')2 is bivalent for antigen binding. The disulfide bonds of F(ab')2 can be cleaved to obtain Fab'. Additionally, the variable regions of the heavy and light chains can be fused to form single chain variable fragments (scFv).

[0097] Pharmaceutically acceptable salts are, for example, acid addition salts and basic salts. Acid addition salts are, for example, HCl or HBr salts. Basic salts are, for example, salts with cations selected from alkali or alkaline earth, for example Na+, or K+, or Ca2+, or ammonium ion N+(R1)(R2)(R3)(R4), where R1-R4 are each independently: hydrogen, an optionally substituted C1-C6 alkyl group, an optionally substituted C2-C6 alkenyl group, an optionally substituted C6-C10 aryl group, or an optionally substituted C6-C10 heteroaryl group. Further examples of pharma-ceutically acceptable salts are described in "Remington's Pharmaceutical Sciences" 17th edition, edited by Alfonso R. Gennaro, Mark Publishing Company, Easton, Pa., USA, 1985, and Encyclopedia of Pharmaceutical Technology.

[0098] Pharmaceutically acceptable solvates are, for example, hydrates.

[0099] It will be further apparent to those skilled in the art that various modifications and changes can be made to the present disclosure without departing from the scope of the present disclosure. Furthermore, it should be noted that any reference signs used in the appended claims shall not be deemed to limit the scope of the present invention.

[0100] In the following, a number of examples of injection devices including a fill level indicator are described in more detail with reference to the drawings. [Brief description of the drawings]

[0101] [Figure 1] 1 shows an example of an injection device. [Diagram 2] FIG. 2 shows an exploded perspective view of the injection device of FIG. 1. [Diagram 3] 1 shows a cross-sectional view through an injection device. [Figure 4]FIG. 4 is an enlarged view of a portion of FIG. 3 with the fill level indicator in an initial configuration. [Diagram 5] FIG. 5 corresponds to FIG. 4, with the fill level indicator in an intermediate configuration. [Figure 6] FIG. 5 is an enlarged view of a portion of the housing of the injection device according to FIG. 4 seen from the outside. [Figure 7] FIG. 6 is an enlarged view of a portion of the housing of the injection device according to FIG. 5 seen from the outside. [Figure 8] FIG. 13 is a cross-sectional view through a fill level indicator engaged with a housing. [Figure 9] 13A-13C are longitudinal sections through further examples of fill level indicators. [Figure 10] 10 is a cross-sectional view through the fill level indicator according to FIG. 9 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0102] One of several examples of an injection device 1 suitable for implementing cartridge fill level indication is shown in Figs. 1 and 2. Here, the injection device 1 is a pre-filled, disposable injection device including 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 either an outer needle cap 17 and / or a protective cap 18 configured to enclose 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 Fig. 2. The distal housing component is generally referred to as a cartridge holder 14. The cartridge holder 14 can be permanently or releasably connected to the body 10.

[0103] The body 10 may form or constitute the main body or main housing of the injection device 1. Additionally, the body 10 may form or constitute a second member according to the terms of the present disclosure. The cartridge holder 14 is typically configured to accommodate a cartridge 6 filled with a liquid medicament. The cartridge 6 includes a barrel 25 of cylindrical or tubular shape sealed in the proximal direction 3 by a bung 7 located in the barrel 25. The bung 7 is displaceable relative to the barrel 25 of the cartridge 6 in the distal direction 2 by a piston rod 20. The distal end of the cartridge 6 is sealed by a pierceable seal 26 configured as a septum and pierceable by the proximally facing tip end of the injection needle 15. The cartridge holder 14 includes a threaded socket 28 at its distal end for threaded engagement with a corresponding threaded portion of the injection needle 15. By mounting the injection needle 15 to the distal end of the cartridge holder 14, the seal 26 of the cartridge 6 is pierced, thereby establishing fluid transfer access to the interior of the cartridge 6.

[0104] When the injection device 1 is configured to administer, for example, human insulin, the dose set by a dose dial 12 at the proximal end of the injection device 1 can be displayed in so-called International Units (IU), with 1 IU being bioequivalent to approximately 45.5 μg (1 / 22 mg) of pure crystalline insulin. The dose dial 12 can be rotatable relative to the housing 90 or body 10 about a longitudinal axis.

[0105] 1 and 2, the body 10 includes a dose window 13, which may be in the form of an aperture within the body 10. The dose window 13 allows a user to view a limited portion of a number sleeve 80 that is configured to move when the dose dial 12 is turned, providing a visual indication of the dose currently set. The dose dial 12 is rotated on a helical path relative to the body 10 when turned during dose setting and / or dispensing or expelling.

[0106] The injection device 1 can be configured to generate a mechanical click sound by turning the dose knob or dose dial 12 to provide acoustic feedback to the user. The number sleeve 80 mechanically interacts with the piston of the insulin cartridge 6. When the needle 15 is inserted into the patient's skin area and the trigger 11 or injection button is pressed, the insulin dose displayed in the display window 13 will be expelled from the injection device 1. When the needle 15 of the injection device 1 remains in the skin area for a period of time after the trigger 11 is pressed, a high percentage of the dose is actually injected into the patient's body. The release of the insulin dose may also generate a mechanical click sound, but it is different from the sound generated when using the dose dial 12.

[0107] In this embodiment, during delivery of an insulin dose, the dose dial 12 is turned to its initial position with an axial movement, i.e., without rotation, while the number sleeve 80 rotates back to its initial position, e.g., to display a dose of zero units.

[0108] The injection device 1 can be used for several injection processes, either until the cartridge 6 is empty or until the expiry date of the drug in the injection device 1 is reached (eg 28 days from first use).

[0109] Furthermore, before the first use of the injection device 1, it may be necessary to perform a so-called "blank shot" to remove air from the cartridge 6 and needle 15, by selecting, for example, two units of drug and pressing the trigger 11 while holding the injection device 1 with the needle 15 up. For ease of presentation, in the following it is assumed that the ejected amount substantially corresponds to the injection dose, whereby, for example, the amount of drug ejected from the injection device 1 is equal to the dose received by the user.

[0110] An example of the drive mechanism 8 is shown in more detail in FIG. 2. The drive mechanism 8 includes a number of mechanically interacting components. The flange-like support of the body 10 includes a threaded axial through-bore that threadably engages with the first or distal thread 22 of the piston rod 20. The distal end of the piston rod 20 includes a bearing 21 on which a pressure holddown 23 is free to rotate about the longitudinal axis of the piston rod 20. The pressure holddown 23 is configured to abut axially against a proximally facing thrust receiving surface of the bung 7 of the cartridge 6. During a dosing action, the piston rod 20 rotates relative to the body 10, which results in a distal forward movement relative to the body 10 and thus relative to the barrel 25 of the cartridge 6. As a result, the bung 7 of the cartridge 6 is displaced in the distal direction 2 by a well-defined distance due to the threaded engagement of the piston rod 20 with the body 10.

[0111] 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 are opposite threads.

[0112] 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 constituting a first member according to the terms of the present disclosure. Here, the first member 30, for example in the form of the dose setting member 30 or the drive sleeve, has a hollow interior for receiving the piston rod 20. The dose setting member 30 comprises an internal thread threadingly engaged with the proximal thread 24 of the piston rod 20. Furthermore, the dose setting member 30 comprises an external threaded section 31 at its distal end. The threaded section 31 is axially limited 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. Between the two flange portions 32, 33, a fill level indicator 35 is provided. In this example, the fill level indicator 35 comprises a semi-circular nut having an internal thread 38 that mates with the threaded section 31 of the dose setting member 30. The fill level indicator 35 may also form or constitute a final dose limiter, for example in the form of a final dose nut.

[0113] The fill level indicator 35 further comprises a radial recess or projection 39 on its outer periphery, which engages with a complementary shaped recess or projection 99 on the inside of the side wall of the body 10. In this way, the fill level indicator 35 is splined to the body 10. Rotating the dose setting member 30 in the dose increment direction 4 or clockwise direction during successive dose setting procedures causes a cumulative axial displacement of the fill level indicator 35 relative to the dose setting member 30. An annular spring 40 is further provided, which axially abuts against a proximally facing surface of the flange portion 33. Furthermore, a tubular shaped clutch 60 is provided. At a first end, the clutch 60 is provided with a series of circumferentially oriented sawtooths. Towards the opposite second end of the clutch 60, a radially inwardly oriented flange is located.

[0114] Further, a dose dial sleeve, also indicated as number sleeve 80, is provided. The number sleeve 80 is provided outside the spring 40 and the clutch 60 and is located radially inside the body 10. A helical 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 portion of the outer surface of the number 80 is visible. The body 10 is further provided with a helical rib on the inner sidewall portion of the insert part 62, which will seat in the helical groove 81 of the number sleeve 80. The tubular shaped insert part 62 is inserted into the proximal end of the body 10. The insert part 62 is axially fixed in a non-rotatable manner relative to the body 10. First and second stops are provided on the body 10 to limit the dose setting procedure to the number sleeve 80 rotating in a helical motion relative to the body 10.

[0115] A dose dial 12 in the form of a dose dial grip is disposed about the outer surface of the proximal end of number sleeve 80. The outer diameter of dose dial 12 typically corresponds to and matches the outer diameter of body 10. Dose dial 12 is fixed to number 80 to prevent relative movement therebetween. Dose dial 12 is provided with a central opening.

[0116] The trigger 11, also indicated as a dose button, is substantially T-shaped. The trigger 11 is provided at the proximal end of the injection device 1. A stem 64 of the trigger 11 extends through an opening in the dose dial 12, through the inner diameter of the extension of the dose setting member 30 and into a receiving recess in the proximal end of the piston rod 20. The stem 64 is held against axial movement within the dose setting member 30 and against rotation relative thereto. The head of the trigger 11 is generally circular. A side wall or skirt of the trigger extends from the periphery of the head and is further adapted to seat in a proximally accessible annular recess of the dose dial 12.

[0117] To dial in a dose, the user rotates the dose dial 12. With the spring 40 also acting as a clicker and the clutch 60 engaged, the dose setting member 30, the spring or clicker 40, the clutch 60 and the number sleeve 80 rotate together with the dose dial 12. An audible or tactile feedback of the dialed-in dose is provided by the spring 40 and the clutch 60. Torque is transmitted between the spring 40 and the clutch 60 via the sawtooth. The helical groove 81 of the number sleeve 80 and the helical groove of 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 to move up the piston rod 20 at the same speed. At the limit of travel, a radial stop of the number sleeve 80 engages either a first stop or a second stop provided on the body 10, preventing further movement in a first rotational direction, e.g. in the dose increment direction 4. Rotation of the piston rod 20 is prevented because the overall threads and the driven threads of the piston rod 20 are in opposite directions.

[0118] The fill level indicator 35, which is hooked to the body 10, advances along the threaded section 31 as the dose setting member 30 rotates. When the final dose dispensing position is reached, a radial stop formed on the surface of the fill level indicator 35 abuts against a second stop 33 of the dose setting member 30 or a radial stop on the proximal flange portion, preventing further rotation of both the fill level indicator 35 and the dose setting member 30.

[0119] If the user inadvertently dials in excess of the desired dose, the injection device 1 configured as a pen injector can be dialed down to a lower dose without dispensing any medicament from the cartridge 6. For this, the dose dial 12 is simply rotated backwards. This causes the system to work 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 clutch 60 causes the sawtooth to ride over each other, producing a clicking sound corresponding to a dial setting that reduces the dose. Typically, the sawtooth are arranged such that the circumferential extent of each sawtooth corresponds to a unit dose. Here, the clutch can act as a ratchet mechanism.

[0120] 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 shaped clutch 60. The at least one ratchet feature may include a protrusion extending radially outward, for example on the free end of the flexible arm. The protrusion is configured to engage a mating ratchet structure of corresponding shape on the inside of the number sleeve 80. The inside of the number sleeve 80 may include a longitudinally shaped groove or protrusion characterized by a sawtooth profile. During dialing or setting of a dose, the ratchet mechanism allows and supports the number sleeve 80 to rotate along the second rotation direction 5 relative to the clutch 60, accompanied by a regular clicking sound of the flexible arm of the clutch 60. The angular momentum applied to the number sleeve 80 along the first rotation direction is transferred invariably to the clutch 60. Here, the mutually corresponding ratchet features of the ratchet mechanism provide a torque transfer from the number sleeve 80 to the clutch 60.

[0121] When the desired dose has been dialed in, the user can simply dispense the set dose by depressing the trigger 11. This causes the clutch 60 to displace axially relative to the number sleeve 80, disengaging its canines. The clutch 60, however, remains latched against rotation relative to the dose setting member 30. The number sleeve 80 and dose dial 12 are now free to rotate according to the helical groove 81.

[0122] This axial movement causes the flexible arm of the spring 40 to deform, ensuring that the sawtooth does not loosen during dosing. This prevents the dose setting member 30 from rotating relative to the body 10, but the dose setting member 30 is still free to move axially relative to the body 10. This deformation is then used to urge the spring 40 and clutch 60 rearward along the dose setting member 30, restoring the connection between the clutch 60 and the number sleeve 80, when the distally directed dosing pressure is then removed from the trigger 11.

[0123] Longitudinal axial movement of the dose setting member 30 causes the piston rod 20 to rotate through a through hole in the support of the body 10, thereby advancing the bung 7 within the cartridge 6. After the dial-set dose has been dispensed, further rotation of the number sleeve 80 is prevented by contact of at least one stop extending from the dose dial 12 with at least one corresponding stop on the body 10. The zero dose position can be determined by the abutment of one of the axially extending edges or stops of the number sleeve 80 with at least one or several corresponding stops on the body 10.

[0124] The ejection mechanism or drive mechanism 8 described herein is merely exemplary of one of several different configurations of drive mechanisms that may be implemented within a disposable pen injector in general. The drive mechanisms mentioned above are described in more detail, for example, in WO2004 / 078239A1, WO2004 / 078240A1 or WO2004 / 078241A1, which are incorporated herein by reference in their entirety.

[0125] In general, the fill level indication mechanism disclosed herein can be implemented by any parking device including a first member 30 and a second member 10, where the first member 30 rotates relative to the second member 10 during and / or for only one of dose setting and dose ejection, and the first member 30 is non-rotatably locked relative to the second member 10 during and / or for the other of dose setting and dose ejection. Any reference herein to the dose setting member 30 may equally apply to the first member. Furthermore, any reference herein to the body 10 or the housing 90 may equally apply to the second member in accordance with the terminology of the appended claims.

[0126] The dose setting mechanism 9 shown in Figure 2 includes at least the dose dial 12 and a number sleeve 80. During setting of a dose, as the dose dial 12 is rotated to set a dose, the number sleeve 80 begins to rotate relative to the housing along a helical path defined by the threaded engagement of its external thread or helical groove 81 with a correspondingly shaped threaded section on the inner surface of the housing.

[0127] During dose setting, when the drive mechanism 8 or dose setting mechanism 9 is in a dose setting mode, the dose setting member 30 rotates together with the dose dial 12 and the number sleeve 80. The dose setting member 30 is threadedly engaged with the piston rod 20, which is stationary relative to the body 10 during dose setting. The dose setting member 30 thus undergoes a threaded or helical movement during dose setting. The dose setting member 30 starts to move in the proximal direction when the dose dial rotates in a first rotational or dose increment direction 4, e.g. clockwise. To adjust or correct the size of the dose, the dose dial 12 is rotatable in an opposite second rotational direction, and thus in a dose decrement direction 5, e.g. counterclockwise.

[0128] 1-5, the proximal end of the cartridge holder 14 is connectable or permanently connected to the distal end of the body 10. To this end, the cartridge holder 14 may include an insert section configured to be inserted into a receptacle provided at the distal end of the body 10. The cartridge holder 14 and the body 10 may be removably or releasably engaged.

[0129] In some examples, the cartridge holder 14 and the body 10 are permanently and / or non-releasably or irremovably engaged, for example by a snap-engagement interconnection, and / or by a pressure-fit engagement, for example provided by an adhesive, or by mutual welding of overlapping portions of the cartridge holder 14 and the body 10. In examples where the cartridge holder 14 and the body 10 are non-removably interconnected, the injection device 1 is embodied as a handheld injection device, which is intended to be completely discarded once the contents of the cartridge have been used up or should no longer be used.

[0130] The first member 30, and thus the dose setting member 30, may be embodied as a drive sleeve and is configured to rotate in a dose increment direction during setting of a dose. For dose correction, the dose setting member may be rotatable in an opposite and thus dose decrement direction relative to the first member, and thus relative to the housing 90 or body 10. During dose ejection or dose dispensing, the dose setting member 30 is normally locked non-rotatably relative to the housing.

[0131] The filling level indicator 35 of the injection device 1 is engaged with the dose setting member 30. The filling level indicator 35 further engages with the elongated housing 90, in particular with the tubular shaped body 10 located in the proximal direction. In the view of Fig. 4, the filling level indicator 35 is located in a start position 100. There, the filling level indicator 35 abuts with a first stop 32 provided on the dose setting member 30. The position, in particular the start position 100 of the filling level indicator 35, is visible from outside the housing through an elongated aperture 91 provided in a side wall of the housing 90, in particular in the side wall of the body 10 shown in Figs. 4-7.

[0132] In the present example, the fill level indicator 35;135 provides a double function. On the one hand, it provides the function of a final dose member or a final dose nut. On the other hand, it indicates the fill level of the medicament provided in the cartridge 6. Here, the longitudinal position of the fill level indicator 35;135 relative to the housing 90 or body 10 directly correlates with the longitudinal position of the piston rod 20 relative to the housing 90 or body 10. The fill level indicator is visually inspectable and / or recognizable from outside the housing 90 in each configuration of the injection device.

[0133] In Figs. 4 to 10, various examples of the fill level indicator 35;135 are shown in relation to a particular example of an injection device 1. Typically, the presently disclosed concept of the fill level indicator 35;135 can be implemented in a wide variety of different injection devices. In some examples, for the implementation of the fill level indicator 35;135, only a first member 30, e.g., a dose setting member 30, is required that is rotatable in the dose increment direction relative to a second member 10, e.g., a body 10, during dose setting and is non-rotatable during dose ejection or dose injection. In other examples, the first member is non-rotatably locked relative to the second member 10 during and / or for dose setting. The first member is then rotatable relative to the second member 10 during and / or for dose ejection.

[0134] In the non-limiting example shown here, the fill level indicator 35 is threadably engaged with the dose setting member 30. To this end, the fill level indicator 35 comprises an inner threaded section 38 that is threadably engaged with a correspondingly shaped outer threaded section 31 of the dose setting member 30. The dose setting member 30 comprises a tubular or sleeve-shaped geometric structure.

[0135] The threaded section 31 extends in the longitudinal direction on the outer surface of the dose setting member 30. The threaded section 31 is delimited in the proximal direction 3 by a second stop 33. The threaded section 31 is delimited in the distal direction 2 by a first stop 32. In the example shown here, the first stop 32 comprises a radially outwardly extending flange portion integrally formed with the dose setting member 30. Similarly, the second stop 33 is also embodied as a radially outwardly extending flange portion. In particular, as shown in FIG. 4, a stop feature 29 can be provided on the distally facing side of the second stop 33. The stop feature 29 can comprise a stop surface, which extends in the longitudinal direction and in the radial direction. Thus, the surface normal of the stop surface of the stop feature 29 extends in the tangential or circumferential direction.

[0136] The fill level indicator 35 may comprise a semicircular half-nut, as shown in Fig. 8. The fill level indicator 35 may be axially engagable with the second stop 33, in particular with a distally facing surface of the flange. Alternatively or additionally, the fill level indicator 35 may comprise stop features 44, 45 at its circumferential or tangential ends configured to abut the stop feature 29 of the second stop 33 in the tangential or circumferential direction. In this way, a fairly steep and well-defined stop configuration may be provided when the fill level indicator 35 reaches the end position 102 shown by the dashed rectangle in Fig. 6.

[0137] At least the indicator portion 36 of the filling level indicator 35, in particular the outwardly facing side wall portion of the filling level indicator 35, is visually perceptible or visible from outside the housing 90. For this purpose, the housing 90, in particular the body 10, which also represents for example the second member, comprises an elongated aperture 91, shown in Figs. 4 to 8. The elongated aperture 91 comprises a longitudinal extension that is identical or substantially coincides with 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 start position 100 towards the end position 102 is always and / or completely visible. As shown in Fig. 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 the housing 90 is substantially protected against the ingress of moisture and / or particles.

[0138] Outside the elongated aperture 91 and offset circumferentially or tangentially therefrom, the housing 90 or body 10 comprises at least one or several radial recesses 99 configured to engage with correspondingly shaped radial projections 39 of the filling level indicator 35, where the radial projections 39 extend radially outwardly from the outer surface of the filling level indicator 35. The correspondingly shaped recesses 99 are provided in an inwardly facing portion of a side wall of the body 10 or housing 90. On the inside of the filling level indicator 35 a threaded section 38 is provided which is in threaded engagement with a mating threaded section 31 on the outside of the dose setting member 30.

[0139] The recess 99 provides a sliding track for the fill level indicator 35. The splined engagement of the projection 39 and the recess 99 non-rotatably locks the fill level indicator 35 relative to the body 10 or housing 90, thereby allowing longitudinal sliding movement of the fill level indicator 35 relative to the body 10 in the longitudinal direction. The longitudinal sliding displacement of the fill level indicator 35 relative to the body 10 is caused by rotation of the dose setting member 30 relative to the body 10, where the degree of rotation of the dose setting member 30 directly corresponds to the dose size.

[0140] An outer surface of the fill level indicator 35 is provided with an indicia portion 36. The indicia portion 36 is the portion of the fill level indicator 35 that is visible from outside the housing 90.

[0141] The fill level indicator 35 further includes a base portion 34. The base portion 34 is the part of the fill level indicator 35 that is mechanically engaged with the dose setting member 30 and the housing 90 or body 10.

[0142] The outer surface of the housing 90 or body 10 is provided along the longitudinal extension of the longitudinal aperture 91 with a scale 94 having a number of marks, text, symbols or numbers thereon which serve to indicate the remaining amount of drug provided in the cartridge when the fill level indicator 35 is positioned adjacent to a respective portion of the scale 94.

[0143] In the configuration shown 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 start position and the amount of medicament in 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. The fill level indicator 35 is therefore located at or near the first longitudinal end 93 of the elongated aperture 91, thus indicating that the initial fill amount of the cartridge is still available.

[0144] A dose of drug is set by rotating the dose setting member 30 relative to the housing 90, causing the fill level indicator 35 to undergo a sliding movement along the elongated aperture 91 towards an end position 102, as shown in Figure 6. The amount of longitudinal displacement is indicated by a pointer 37 of the marking portion 36 pointing towards a particular marker and / or indication on the scale 94, as shown in Figure 7.

[0145] When the dose has been set and the fill level indicator 35 has been moved towards the end position 102, the piston rod 20 is still positionally locked relative to the housing 90 or body 10. It is only during a subsequent dose dispensing or dose expelling procedure that the piston rod 20 is advanced distally relative to the barrel 25 of the cartridge 6, thereby expelling the respective drug quantity from the cartridge, typically through penetration of the injection needle 15 through a portion of the patient's injection site.

[0146] In the intermediate position 101 of the fill level indicator 35 shown in Figures 5 and 7, the fill level indicator 35 is longitudinally separated from both the first stop 32 and the second stop 33. The distance to the second stop 33, and thus the distance between the indicating portion 36 and the second longitudinal end 95 of the longitudinal aperture 91, indicates the remaining amount of drug still available in the cartridge 6. The patient or device user quickly perceives the remaining contents of the cartridge without being forced to detach or remove the protective cap 18 from the cartridge holder 14 in order to visually inspect the drug in the cartridge.

[0147] In this way, the cartridge holder 14 can be made from a translucent material and the medicament located in the cartridge 6 can be enclosed by the opaque and thus translucent cartridge holder, as the fill level indicator 35 immediately indicates the remaining fill level of the cartridge. In this way, the medicament located in the cartridge 6 can be protected against electromagnetic radiation when assembled in the injection device 1 and when received in the cartridge holder 14.

[0148] In a further example shown in Figures 9 and 10, the fill level indicator 135 also comprises an inner threaded section 138 in threaded engagement with the threaded section 31 of the dose setting member 30. Again, a radial protrusion 139 of the fill level indicator 135 is in sliding engagement with the housing 90 or the body 10 of the injection device 1. Again, the fill level indicator 135 comprises a base portion 134 in mechanical engagement with both the housing 90 and the dose setting member 30. In contrast to the examples described above in relation to Figures 4, 5 and 8, the fill level indicator 135 comprises an indication portion 142 located on the outside of the housing 90 or on the outside of the body 10.

[0149] Here, the fill level indicator 135 includes an L-shaped rod 140 including an indicator portion 142 and a bridging portion 141. The bridging portion 141 is connected to or integrally formed with a longitudinal end of the elongated indicator portion 142. Also, the bridging portion 141 is connected to or integrally formed with a base portion 134 of the fill level indicator 135. The bridging portion 141 extends through an elongated aperture 91 in the housing 90 or body 10. In this manner, the bridging portion 141 is longitudinally splined or slidingly engaged with the housing 90 or body 10. Thus, the fill level indicator 135 is locked to the housing 90 or body 10 through 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 manner, a substantially tight sliding engagement between the housing 90 or body 10 and the fill level indicator 135 can be provided.

[0150] In this example, the further protrusion 139 of the fill level indicator 135 may be dispensed with. The fill level indicator 135 may therefore also be implemented without the radially outwardly extending protrusion 139. The housing 90 or body 10 may therefore be devoid of the elongated recess 99. The longitudinal sliding engagement between the housing 90 and the fill level indicator 135 may be provided and obtained exclusively by a bridging portion 141 extending through the elongated aperture 91 of the housing.

[0151] The bridging portion 141 further includes at least one stop surface 144 facing towards the end position 102 and thus towards the second longitudinal end 95 of the elongated aperture 91. When approaching the end position 102, the stop surface 144 abuts the second longitudinal end 95 of the elongated aperture 91, thereby preventing further displacement of the fill level indicator 135 beyond the end position 102.

[0152] Due to the threaded engagement between the fill level indicator 135 and the dose setting member 30, further dose incremental rotation of the dose setting member to set a dose beyond the amount of drug remaining in the cartridge 6 can be effectively prevented.

[0153] The fill level indicator 135 therefore fulfils a dual function: on the one hand, it visually indicates the amount of medication remaining provided in the cartridge 6. On the other hand, it provides an end stop that prevents dialling or setting a dose beyond the amount of medication remaining provided in the cartridge.

[0154] In the example of Figures 9 and 10, the elongated aperture 91 of the housing 90 does not have a covering window 92. Rather, as shown in Figure 9, each part of the housing 90 can be enclosed or provided with an outer housing 150. The outer housing 150 covers at least the aperture 91. The outer housing 150 also covers at least a portion or the entire rod-shaped elongated indicator portion 142 of the fill level indicator 135. The outer housing 150 can cover the entire L-shaped rod 140 in the longitudinal direction and at any available position of the fill level indicator 135 relative to the housing 90 or body 10.

[0155] 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. The entire elongated indicator portion 142 or only a portion thereof may be visible in the transparent portion 152 of the outer housing 150. One of the indicator portion 142 and the transparent portion 152 is or can be provided with a scale, while the other of the indicator portion 142 and the transparent portion 152 is provided with a pointer pointing towards the scale.

[0156] The outer housing 150 may be translucent at least in the area covering the elongated aperture 91 of the housing 90 or body 10. In this manner, the internal structure or interior of the dose setting mechanism 9 and / or drive mechanism 8 may remain covered and invisible from the outside of the housing 90 or outer housing 150. [Explanation of symbols]

[0157] 1. Injection device 2 Distal direction 3 Proximal direction 4 Dose Increment Direction 5 Dose decrement direction 6 Cartridges 7 Stopper 8 Driving mechanism 9 Dose setting mechanism 10 Second member 11 Trigger 12 Dose Dial 13 Dosage window 14 Cartridge holder 15 Syringe needle 16 Inner needle cap 17 Outer needle cap 18 Protective Cap 19 Protrusion 20 Piston rod 21 Bearing part 22 1st thread 23 Pressure Holder 24 Second Thread 25 barrels 26 Sealing part 28 Threaded Socket 29 Fastener function 30 First member 31 Threaded Section 32 Fastener 33 Fastener 34 Base part 35 Fill level indicator 36 Marking part 37 Pointer 38 Threaded Section 39 Protrusion 40 Spring 50 Dose Tracking Section 51 Fastener tracking function 60 Clutch 62 Insert piece 64 Stem 80 Number Sleeve 81 Groove 90 Housing 91 Aperture 92 Windows 93 Longitudinal End 94 Scale 95 Longitudinal End 99 Recess 100 starting position 101 Intermediate position 102 End position 134 Base part 135 Fill Level Indicator 138 Threaded Section 139 Protrusion 140 Rod 141 Crosslinked part 142 Marking part 144 Fastener surface 150 Outer Housing 152 Transparent Parts

Claims

1. 1. A pen injection device for setting and injecting a dose of medication, comprising: a longitudinally extending elongated housing (90) configured to receive a cartridge (6); a first member (30) movably disposed within an elongated housing (90) for setting a dose; a piston rod (20) configured to advance in a longitudinal distal direction (2) and operable to exert distal pressure on a bung (7) of the cartridge (6) to expel a dose; during one of setting the dose and ejecting the dose, the first member (30) is rotatable relative to the elongated housing (90), and during the other of setting the dose and ejecting the dose, the first member (30) is non-rotatably locked relative to the elongated housing (90); The injection device may further comprise: a fill level indicator (35; 135) threadedly engaged with one of the first member (30) and the elongated housing (90), the fill level indicator (35; 135) being non-rotatably locked and longitudinally slidably engaged with the other of the first member (30) and the elongated housing (90); the fill level indicator (35; 135) is longitudinally movable relative to the first member (30) and / or relative to the elongated housing (90) from at least a start position (100) to an end position (102); the fill level indicator (35; 135) is visible from outside the housing (90) when the fill level indicator (35; 135) is in the starting position (100); The injection device, wherein the elongated housing (90) includes an elongated aperture (91) extending along its longitudinal direction and is provided with a scale (94), at least a marking portion (142) of the fill level indicator (135) is located on the outside of the elongated housing (90), and a pointer (37) is provided to point towards the marker or indication on the scale (94).

2. 2. The method of claim 1, wherein the fill level indicator (35; 135) is visible from outside the housing (90) when the fill level indicator (35; 135) is in the end position (102).

2. An injection device as described in claim 1.

3. 3. An injection device according to claim 1 or 2, wherein the filling level indicator (35; 135) is visible from outside the housing (90) at any position (101) between the start position (100) and the end position (102).

4. An injection device according to any one of claims 1 to 3, wherein one of the first member (30) and the elongated housing (90) includes a first stop (32) and a second stop (33), the first stop (32) and the second stop (33) being spaced apart from each other along the longitudinal direction.

5. 5. The injection device of claim 4, wherein the fill level indicator (35; 135) engages the second stop (33) when in the end position (102), and the fill level indicator (35; 135) is operable to prevent further movement of the first member (30) relative to the elongated housing (90) in at least one direction of movement when the fill level indicator (35; 135) is engaged with the second stop (33).

6. An injection device according to any one of claims 1 to 5, wherein the housing (90) includes an elongated aperture (91) extending along the longitudinal direction, and at least the indicating portion (36) of the filling level indicator (35) is visible through the elongated aperture (91).

7. 7. An injection device according to claim 6, wherein the elongated aperture (91) is covered or closed by a transparent window (92).

8. An injection device according to any one of claims 1 to 7, wherein the fill level indicator (135) comprises an L-shaped rod (140) including an indicating portion (142) and a bridging portion (141), the bridging portion (141) extending through the aperture (91).

9. An injection device according to any one of claims 1 to 8, further comprising an outer housing (150) covering or enclosing at least a portion of the housing (90) in the area of ​​the fill level indicator (135), the outer housing (150) including a transparent window (152) overlapping at least the indicated portion (142) of the fill level indicator (135).

10. An injection device according to any one of the preceding claims, wherein the housing (90) comprises a cartridge holder (14) configured to accommodate the cartridge (6), the cartridge holder (14) being translucent.

11. An injection device according to any one of claims 6 to 10, wherein the housing (90) includes a scale (94) extending along the elongated aperture (91), and the marking portion (36; 142) includes a pointer (37; 137) pointing towards the scale (94).

12. 12. An injection device according to any one of claims 1 to 11, wherein the filling level indicator (35; 135) comprises a threaded section (38; 138) and at least one of a radial protrusion (39; 139) or a radial recess, the threaded section (38; 138) being engaged with a correspondingly shaped mating threaded section (31) of one of the first member (30) and the elongated housing (90), and at least one of the radial protrusion (39; 139) or the radial recess being in longitudinal sliding engagement with a correspondingly shaped radial recess (99) or radial protrusion of the other of the first member (30) and the elongated housing (90).

13. An injection device according to any one of the preceding claims, wherein the first member (30) is movable relative to the elongate housing (90) only during one of setting the dose and dispensing the dose.

14. An injection device according to any one of the preceding claims, further comprising a cartridge (6) filled with a medicament and arranged within the elongated housing (90).

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