Mechanism unit for a drug delivery device and drug delivery device

Abstract

An institutional unit for a drug delivery device, the institutional unit comprising a housing (10), a piston rod (30), and a dose setting and driving mechanism configured to perform a dose setting operation and a dose delivery operation by transmitting a delivery force to the piston rod (30) so as to drive the piston rod (30) in a distal direction during the dose delivery operation, wherein the dose setting and driving mechanism includes a first driving member (40a), a second driving member (40b), and an adapter mechanism having at least two different states: a setting state and a delivery state, wherein, in the setting state, the second driving member (40b) is rotationally fastened relative to the housing (10) at least against rotation in the delivery direction, and wherein, in the delivery state, the second driving member (40b) is rotatable relative to the housing (10) in the delivery direction, wherein, in the setting state, the first driving member (40a) is rotatable relative to the second driving member (40b) at least in the delivery direction, and wherein, in the delivery state, the second driving member (40b) is rotationally locked to the first driving member (40a) at least against rotation of the second driving member (40b) relative to the first driving member (40a) in the delivery direction.

Description

Technical Field

[0001] The present disclosure relates to a mechanism unit for a drug delivery device. The present disclosure further relates to a drug delivery device comprising the mechanism unit and a method of manufacturing a drug delivery device. Background Art

[0002] In a drug delivery device, especially in the case of a drug delivery device operated by a patient without medical training, it is of utmost importance that, when dispensing a drug from a cartridge or reservoir during device use, the magnitude of the dose delivered by the drug delivery device corresponds as consistently as possible to the magnitude set by the user. Drug delivery devices typically use a piston rod that is moved by a drive mechanism of the device and is arranged to drive distally a stopper within a reservoir body of the reservoir holding the drug relative to the reservoir body in order to dispense the drug from the reservoir. The distance between the distal end of the piston rod and the proximal end of the stopper facing each other may vary significantly after the initial assembly of the device during the manufacture of the drug delivery device. From a manufacturing perspective, the piston rod can be positioned relatively accurately relative to the housing of the drive mechanism of the drug delivery device. However, for example due to the deformable material typically used for the stopper, it is generally difficult to ensure that the position of the stopper relative to the reservoir body is precisely set for reservoirs having nominally the same liquid filling level. Therefore, the initial position of the stopper relative to the reservoir body may vary. Variations in the dimensions of the reservoir body may have a similar effect, although the effect of the stopper may be more significant. The variations mentioned increase the variation in the distance between the distal end of the piston rod and the proximal end of the stopper in different devices after the device has been assembled. Therefore, the initial target distance between the piston rod and the stopper that should be achieved during the assembly process of the device must be chosen large enough to account for a wide range of possible stopper positions relative to the reservoir body in order to avoid the piston rod already exerting pressure on the stopper during the assembly of the device, which is undesirable, for example because it exerts a mechanical preload on the stopper. Therefore, fluctuations in the stopper position generally require the selection of a relatively large initial target distance.

[0003] A defined initial position between the stopper and the piston rod for various devices can be achieved by measures that allow a variable connection between the drive mechanism and the reservoir or reservoir unit, i.e., it does not rely on fixed elements having defined positions on the respective units, the reservoir unit and the drive mechanism unit. Connection methods allowing a variable connection are, for example, adhesive connection or welded connection. However, if a more reliable connection should be used (such as a connection established by means of, for example, rigid fixing features or fastening features for a form-fitting connection), the relative position between the stopper and the piston rod after device assembly still varies due to variations in the reservoir unit, sometimes significantly.

[0004] In order to achieve a defined position between the piston rod and the stopper before the first dose is administered to a patient, a so-called pre-injection step is sometimes used, in which the user has to perform a dose setting and delivery step before the first (self-)administration of the drug occurs. This process is commonly referred to as "air shot". However, this process is still unsatisfactory because it is uncertain whether the user (although instructed to do so) actually performs the step.

[0005] Furthermore, if the drug concentration in the reservoir increases, it may even occur that the initial distance between the piston rod and the stopper is so large that it is greater than the conventional dose dispensed by the drug delivery device (e.g., greater than the minimum settable dose or a larger dose) or even greater than the maximum settable dose that can be dispensed by the drug delivery device in one dispensing operation. Thus, before the drug can be dispensed via displacement of the stopper relative to the reservoir body, the first dose set to be dispensed may be completely absorbed by the initial gap between the piston rod and the stopper that has to be closed. This is of course highly problematic. In addition, the second dose may still not be accurately dispensed even if a pre-injection dose has been dispensed because there may still be a considerable gap after the first dose has been dispensed.

[0006] One option to achieve a defined initial position is to conveniently activate the drive mechanism by setting the dose and dispensing the set dose after the device has been assembled and even before the device is provided to the user, until the piston rod has reached the desired position. However, drug delivery devices, especially those configured to dispense variable (e.g., user-settable) doses of drugs, typically include a mechanism for tracking the contents of the reservoir or the end of the maximum amount that can be dispensed from the reservoir. The size of this mechanism is determined such that it ensures that when the final dose has been dispensed, there is still some drug left in the reservoir (i.e., the reservoir is overfilled). Of course, this takes care of avoiding the risk of underdosing. The tracking mechanism for tracking the end of the contents of the reservoir typically has a tracking member that moves towards the end position relative to a guide track when setting the dose and does not move relative to the guide track when delivering the set dose. When the tracking member reaches the end position, the reservoir is considered empty. At the end position, further increasing the set dose can be prevented by the tracking member.

[0007] Typically, a drug delivery device dispenses a dose in integer multiples of a unit increment. Since the tracking member also moves during the first setting and dispensing of the dose (which can be performed to eliminate the initial clearance between the piston rod and the stopper as described above), this results in that when assembling various devices having nominally the same construction, the reservoir must be overfilled with the drug by at least an amount corresponding to the maximum initial distance between the piston rod and the stopper. As a result, this overfilled drug is lost because it is generally not dispensed. The amount of drug that must be overfilled can even be greater than the maximum dose that can be set with the device, as already explained above. Summary of the Invention

[0008] The object of the present disclosure is to provide an improved assembly for a drug delivery device, an improved drug delivery device, and / or an improved method for manufacturing a drug delivery device. This object is achieved by the subject matter of the independent claims and can also be achieved by the other disclosed subject matter. Further advantageous embodiments and improvements are the subject matter of the dependent claims and the following disclosure.

[0009] In an embodiment, there is provided a mechanism unit for a drug delivery device, the mechanism unit comprising: a housing having a proximal end and a distal end; a piston rod movable relative to the housing, for example, movably held in the housing; a dose setting and driving mechanism configured to perform a dose setting operation for setting a dose to be delivered and a dose delivery operation for delivering the set dose by transmitting a delivery force to the piston rod so as to drive the piston rod in a distal direction relative to the housing during the dose delivery operation, the dose setting and driving mechanism including a first driving member and a second driving member, the first driving member mechanically cooperating with the piston rod to transmit the delivery force to the piston rod, the first driving member being axially fastened and rotatable relative to the housing, wherein rotation of the first driving member relative to the housing in the delivery direction causes the piston rod to move in the distal direction, and rotation in a direction opposite to the delivery direction causes proximal movement of the piston rod, the second driving member being arranged to be mechanically coupled to the first driving member to transmit the delivery force to the first driving member, wherein the dose setting and driving mechanism includes an adapter mechanism having at least two different states: a setting state and a delivery state, wherein, in the setting state, the second driving member is rotationally fastened relative to the housing at least against rotation in the delivery direction, and wherein, in the delivery state, the second driving member is rotatable relative to the housing in the delivery direction, wherein, in the setting state, the first driving member is rotatable relative to the second driving member and the housing at least in the delivery direction, and wherein, in the delivery state, the second driving member is rotationally locked to the first driving member at least against rotation of the second driving member relative to the first driving member in the delivery direction.

[0010] Since the first drive member is rotatable relative to the second drive member in the delivery direction in a set state, for example, before the final assembly of the drug delivery device, the piston rod can be moved in the distal direction. This is preferably done by direct manual or automatic rotation of the first drive member (e.g., by an auxiliary tool). When assembling the device, for example, via a connection mechanism unit and a reservoir unit, such rotation allows the piston rod to move in the distal direction until the desired distance between the proximal end of the stopper in the reservoir of the reservoir unit and the distal end of the piston rod is reached. This enables precise adjustment of the desired distance between the stopper and the piston rod before the first delivery dose and the first operation of the drive mechanism, regardless of the stopper position, the size of the reservoir, or the original filling level. In this way, one or more air expulsions can be avoided before administering the drug to the patient using the drug delivery device. This not only means no waste of the drug, but also means a significant improvement in the user-friendliness and thus the safety of the drug delivery device after assembly.

[0011] In an embodiment, the mechanism unit is configured to be connected to the reservoir unit to assemble the two units for a drug delivery device.

[0012] This allows adjustment of the piston rod position before assembling the drug delivery device into an operating state (in which it may be handled by a patient or customer). This can be particularly advantageous if the mechanism unit is used for reservoir units of different designs (which may, for example, have different positions of the stopper).

[0013] In an embodiment, the first drive member is accessible from the outside of the housing for manipulation, such that in a set state, the position of the piston rod relative to the housing is adjustable by rotation of the first drive member, preferably before or after the connection of the mechanism unit and the reservoir unit.

[0014] The accessibility of the first drive member from the outside of the housing allows adjustment of the piston rod when the mechanism unit has been assembled but the drug delivery device has not been fully assembled.

[0015] In an embodiment, the first drive member is accessible from the distal end of the housing for manipulation. Then, in a set state, the position of the piston rod relative to the housing can be adjusted by rotation of the first drive member. This can be done before connecting the mechanism unit and the reservoir unit.

[0016] In an embodiment, the first drive member is accessible from the proximal end of the housing for manipulation. Then, in a set state, the position of the piston rod relative to the housing can be adjusted by rotation of the first drive member. This can be done before or after connecting the mechanism unit and the reservoir unit.

[0017] The accessibility of the first drive member from the proximal end of the housing allows the adjustment of the piston rod before the drug delivery device is fully assembled and before or after connecting the connecting mechanism unit and the reservoir unit. The opening through which the first drive member can be accessed can be closed by a closing member (e.g., a button member), which provides a user interface for the drug delivery device.

[0018] In an embodiment, the second drive member can be axially moved relative to the first drive member and the housing, for example, in the distal direction, for switching between a set state and a delivery state. Preferably, the second drive member moves distally from an initial position relative to the first drive member and the housing in the set state such that the mechanism unit transitions to the delivery state, wherein the second drive member moves proximally relative to the first drive member and the housing in the delivery state such that the mechanism unit transitions to the set state.

[0019] In an embodiment, the first drive member is engaged to the piston rod. The piston rod can be engaged to the housing. Preferably, the first drive member is directly engaged with the piston rod.

[0020] This allows the movement of the first drive member relative to the housing to have a direct effect on the axial position of the piston rod relative to the housing.

[0021] In an embodiment, the first drive member is threadedly engaged to the piston rod. The piston rod can be splined to the housing.

[0022] In an embodiment, preferably in the delivery state and / or the set state, the first drive member can be rotated relative to the piston rod.

[0023] The threaded engagement of the first drive member with the piston rod causes a rotational movement of the first drive member, thereby causing an axial displacement of the piston rod. This enables the piston rod to be moved to a desired position relative to the housing.

[0024] In an embodiment, the first drive member is splined to the piston rod. The piston rod can be threadedly engaged to the housing.

[0025] In an embodiment, preferably in the delivery state and / or the set state, the first drive member is rotationally constrained relative to the piston rod in the delivery direction and in the direction opposite to the delivery direction.

[0026] This allows the movement of the first drive member to have a direct effect on the axial position of the piston rod relative to the housing.

[0027] In an embodiment, preferably in the delivery state and / or the set state, the first drive member is fastened against proximal and distal movement relative to the housing.

[0028] In an embodiment, the first drive member and / or the second drive member is a sleeve.

[0029] In an embodiment, the piston rod extends through the first drive member and / or the second drive member.

[0030] In an embodiment, the first drive member includes a first locking feature and the second drive member includes a second locking feature. The first locking feature and the second locking feature may be configured to interact to rotationally lock the first drive member and the second drive member against relative rotation in at least one direction and / or both directions. Preferably, when the first locking feature and the second locking feature mechanically interact (e.g., engage with each other), the second drive member cannot rotate relative to the first drive member at least in the delivery direction.

[0031] In an embodiment, the first locking feature is rotationally and axially immovable relative to the first drive member. The second locking feature may be rotationally and axially immovable relative to the second drive member.

[0032] In an embodiment, in the delivery state, the first locking feature engages with the second locking feature.

[0033] In an embodiment, in the set state, the first locking feature and the second locking feature are disengaged.

[0034] In an embodiment, the first locking feature and the second locking feature are disengaged in the set state, and the first locking feature is rotatable relative to the second locking feature in the set state.

[0035] In an embodiment, in the set state, the first locking feature engages with the second locking feature.

[0036] In an embodiment, the first locking feature and the second locking feature are configured such that if the first locking feature engages with the second locking feature, the first locking feature may be rotatable relative to the second locking feature in the delivery direction and rotationally fastened relative to the second locking feature in the direction opposite to the delivery direction. This means that the second drive member cannot rotate relative to the first drive member in the delivery direction.

[0037] In an embodiment, the first locking feature and the second locking feature are designed such that when the first locking feature engages with the second locking feature, the first drive member may occupy one of a number of stable positions relative to the second drive member, wherein the angular distance between the stable positions may be adjusted to (e.g., correspond to) the angle by which a user must rotate a dose setting member to set the minimum dose that can be delivered by the drug delivery device. This dose may correspond to a unit increment.

[0038] In an embodiment, the first locking feature and the second locking feature are designed such that the distance between the stable positions is such that movement of the first drive member relative to the second drive member from one of the stable positions to the next immediately adjacent stable position will at most result in an axial movement of the piston rod which corresponds to an axial movement of the piston rod during the delivery of one unit increment of dose.

[0039] In an embodiment, the first locking feature and the second locking feature are designed as matching ratchet teeth.

[0040] In an embodiment, the dose setting and drive mechanism comprises a dose setting member movable relative to the housing from an initial position to a dose setting position in a set state for setting a dose of the drug, in particular when the device has been fully assembled.

[0041] In an embodiment, the dose setting member is rotationally constrained relative to the second drive member in the delivery state and is rotatable relative to the second drive member in the set state.

[0042] In an embodiment, the first drive member is rotationally constrained to the dose setting member and the second drive member in a direction opposite to the delivery direction in the delivery state. Furthermore, in the delivery state, the first drive member may be rotatable relative to the dose setting member and the second drive member in the delivery direction.

[0043] In an embodiment, in the set state, the first drive member is rotatable relative to the dose setting member and the second drive member in the delivery direction. Furthermore, the first drive member may be rotatable relative to the dose setting member and the second drive member in the delivery direction and in a direction opposite to the delivery direction in the set state.

[0044] In an embodiment, the mechanism unit includes an energy storage device. The energy storage device may be configured such that, in a set state, energy is stored in the energy storage device due to movement of a setting member, preferably a dose setting member, by a user. The energy storage device may be configured such that, in a delivery state, stored energy in the energy storage device is released to support the delivery process. The energy storage device may be a drive spring.

[0045] In an embodiment, a drug delivery device is provided, comprising a mechanism unit, preferably as further described above.

[0046] In an embodiment, the drug delivery device comprises a reservoir unit, wherein the reservoir unit comprises or is provided for holding a reservoir containing the drug.

[0047] In an embodiment, the reservoir is a cartridge.

[0048] In an embodiment, the drug delivery device is an injection device, such as a needle-based injection device, preferably a pen injector.

[0049] In an embodiment, a method of manufacturing a drug delivery device is provided, the method comprising the steps of:

[0050] a) providing a reservoir unit comprising a reservoir containing a drug, wherein a stopper is movably held in the reservoir, and the reservoir is held in a reservoir unit body;

[0051] b) providing the above-mentioned mechanism unit;

[0052] c) determining the stopper position of the stopper relative to the reservoir unit body;

[0053] d) determining the desired piston rod position of the piston rod relative to the housing based on the determined stopper position, wherein the desired piston rod position is determined such that if the mechanism unit is connected to the reservoir unit, the piston rod and the stopper are arranged at a predetermined distance relative to each other, and determining a specific displacement distance by which the piston rod must be displaced in the distal direction relative to the housing to be in the desired piston rod position;

[0054] e) in a set state of the mechanism unit, rotating the first drive member relative to the second drive member to displace the piston rod a specific displacement distance relative to the housing; and

[0055] f) connecting the reservoir unit and the mechanism unit to each other after or before step e).

[0056] Thus, the rotation of the first drive member allows for the exact positioning of the distal end of the piston rod relative to the proximal end of the stopper. Thus, the size of the first dose delivered by the drug delivery device does indeed precisely correspond to the size set by the user. Thus, neither air injection is necessary nor is there a risk that the patient will receive the wrong dose.

[0057] These and other aspects, advantages and conveniences will become apparent from the embodiments described below. Description of the Drawings

[0058] Embodiments will now be described by way of example only with reference to the drawings, in which:

[0059] Figure 1 A top view of a drug delivery device according to a first embodiment of the present disclosure is shown;

[0060] Figure 2 shows Figure 1 an exploded view of the components of the device;

[0061] Figure 3a shows a cross-sectional view of the proximal end of the Figure 1 device in a set state;

[0062] Figure 3b shows a cross-sectional view of the proximal end of the Figure 1 device in the dose delivery state;

[0063] Figure 4 shows a cross-sectional view of the details of the device according to a second embodiment of the present disclosure;

[0064] Figure 5a A cross-sectional view showing the details of the device according to a third embodiment of the present disclosure;

[0065] <00ness="font-family: Arial;"> Figure 5b Shows Figure 5a details of the embodiment.

[0066] Figure 6a A cross-sectional view showing an embodiment of the drive member in the set state;

[0067] Figure 6b Shows Figure 6a a cross-sectional view of the drive member in the delivery state;

[0068] Figure 7a A cross-sectional view showing another embodiment of the drive member in the set state;

[0069] Figure 7b Shows Figure 7a a cross-sectional view of the drive member in the delivery state;

[0070] Figure 8 A schematic diagram showing the interface in the drive member;

[0071] Figure 9a A cross-sectional view showing yet another embodiment of the drive member in the delivery state;

[0072] Figure 9b Shows Figure 9a an embodiment in the set state;

[0073] Figure 9c Shows Figure 9a and Figure 9b additional cross-sectional views of the embodiment;

[0074] Figure 9d Shows Figure 9a and Figure 9b yet another cross-sectional view of the embodiment;

[0075] Figure 10a A cross-sectional view showing yet another embodiment of the drive member in the set state;

[0076] Figure 10b Shows Figure 10aCross-sectional view of an embodiment;

[0077] Figure 10c shows Figure 10a and Figure 10b another cross-sectional view of an embodiment;

[0078] Figure 10d shows Figure 10a and Figure 10b yet another cross-sectional view of an embodiment; and

[0079] Figure 11 shows a view of the surface of a first drive member according to any one of the embodiments of Figures 9a to 10d . DETAILED DESCRIPTION

[0080] Figure 1 shows a drug delivery device in the form of an injection pen. The device has a distal end ( Figure 1 the left end in Figure 1 ) and a proximal end (

[0081] the right end in Figure 1 ). The component parts of the drug delivery device are shown in FIG. 2. The drug delivery device includes a body or housing 10, a reservoir unit body (or cartridge holder) 20, a piston rod (or lead screw) 30, a drive member (or drive sleeve) 40, a nut 50, a dose setting member (or dose indicator or digital sleeve or graduated cylinder) 60, a button 70, a dial grip or dose selector 80, a torsion spring 90, a reservoir (or cartridge) 100, a metering element 110, an adapter plate 120, an adapter spring 130, and a bearing 140. A needle arrangement (not shown) having a needle hub and a needle cap can be provided as an additional component, which can be replaced as explained above. All components are concentrically positioned about a common main axis I (FIG. 3b) of the mechanism.

[0082] In Figure 1 to the embodiment of FIG. 3b, the housing includes an insert 12 as an integral part, which is positioned on the inner wall near the distal end of the housing. The insert 12 can be molded from a translucent material. As an alternative, the insert or a part thereof can be formed from an opaque material or formed as separate component parts as depicted in the embodiment of FIG. 4.

[0083] The insert 12 is a cup-shaped component part having a side wall 13 and a tube 14 extending through the insert 12, thereby forming an annular space therebetween. Arms 15 extend radially outward from the side wall 13. A bottom wall 16 connects the side wall 13 and the tube 14 on the distal side of the insert 12, while the opposite proximal side is open. The insert 12 has various interfaces. For example, the tube 14 of the insert 12 includes an internal thread 17 for engaging the piston rod 30. Further, the radial space between the tube 14 and the outer side wall 13 can provide a support area for receiving the drive spring 90 and the adapter spring 130. Further, spline teeth 18 are provided on the insert 12 for engaging corresponding spline teeth 41 at the distal end of the drive member 40. The teeth 18 interact with the drive member 40 to steerably couple and decouple the drive member from the housing 10.

[0084] In the embodiment of FIG. 4, the insert is an integral part of the inner housing portion of the housing, and the inner housing portion is partially surrounded by the housing outer shell portion. The housing portions can be formed by two successive injection moldings such that the housing portions are permanently attached to each other. For example, the inner housing portion is formed of a transparent or translucent material, while the outer shell portion is formed of an opaque material.

[0085] In Figure 5a and Figure 5b 's embodiment, the insert 12 is partially formed as a single component part with the housing 10 and partially formed as a separate component part 19. The cup-shaped body 13 and the threaded tube 14 having an annular space for a compression spring are integrally formed with the housing 10 and are connected to the housing via the arms 15, while the adapter features 18 for steerably constraining the drive member 40 are separate annular component parts 19 that are axially and steerably constrained to the housing 10. Thus, according to Figure 5a and Figure 5b 's embodiment, the annular insert part 19 does not have the thread 17 as an integral part. As more particularly shown in Figure 5b , the annular insert part 19 includes axially oriented splines 19a on its inner surface to steerably limit the drive member 40. The annular insert part 19 further includes arms or splines 19b located on its outer surface for rotational retention within the housing 10. Further, a number of hook-shaped arms 19c are provided to form a snap-fit fixture for axially retaining the annular insert part 19 within the housing 10. The annular insert part 19 includes a hole or recess 19d for receiving and securing the hook end 91 of the drive spring 90. Further, features are present on the annular insert part 19 to axially and steerably bias the insert parts 12, 19 to remove free play.

[0086] The reservoir unit body 20 is located distally of and permanently attached to the housing 10. The reservoir unit body can be a transparent or translucent component and is tubular to receive the reservoir 100. The distal end of the reservoir unit body 20 may be provided with means for attaching the needle arrangement. A removable cap (not shown) may be provided to fit over the reservoir unit body 20 and may be held by a clamping feature on the housing 10.

[0087] The piston rod 30 is rotationally constrained to the drive member 40 via a spline interface. When rotated, the piston rod 30 is forced to move axially relative to the drive member 40 through its threaded interface with the insert 12 of the housing 10. The piston rod 30 is an elongate member having external threads to engage corresponding threads of the insert 12 of the housing 10. The interface includes at least one longitudinal groove or track and corresponding protrusions or splines of the drive member 40. At its distal end, the piston rod 30 is provided with an interface for clamping the attachment bearing 140.

[0088] The drive member 40 is a hollow member that surrounds the piston rod 30 and is disposed within the dose setting member 60. It extends from an interface with the adapter plate 120 to contact the adapter spring 130. The drive member 40 is axially movable relative to the housing 10, the piston rod 30, and the dose setting member 60 against the bias of the adapter spring 130 in the distal direction and under the bias of the adapter spring 130 in the opposite proximal direction.

[0089] The splined tooth interface 18 with the insert 12 prevents rotation of the drive member 40 during dose setting. This interface includes a ring of external teeth 41 that radially extend at the distal end of the drive member 40 and corresponding radially extending internal teeth 18 of the housing component 10 (insert 12). When the button 70 is pressed (Figure 3b), these drive member - housing insert splined teeth disengage, allowing the drive member 40 to rotate relative to the insert and thus relative to the housing 10. The adapter spring 130 biases the drive member 40 into a position where its teeth 41 engage the teeth 18 of the insert (Figure 3a). During dialing, additional splined teeth that interface with the dose setting member 60 are not engaged but engage when the button 70 is pressed, preventing relative rotation between the drive member 40 and the dose setting member 60 during dispensing. In a preferred embodiment, this interface includes inwardly directed splines on a flange on the inner surface of the dose setting member 60 and a radially extending external spline ring of the drive member 40. These corresponding splines are located on the dose setting member 60 and the drive member 40 such that axial movement of the drive member 40 relative to the (axially fixed) dose setting member 60 causes the splines to engage or disengage, thereby rotationally coupling or decoupling the drive member 40 and the dose setting member 60.

[0090] Additional interfaces of the drive member 40 include a ratchet tooth ring located at the proximal face of the drive member 40 and a corresponding ratchet tooth ring on the adapter plate 120.

[0091] The drive member 40 has a threaded section to provide a helical track for the nut 50. Additionally, a final dose abutment or stop is provided, which can be the end of the threaded track or preferably a rotational hard stop for interaction with a corresponding final dose stop of the nut 50, thus restricting movement of the nut 50 on the drive threads. At least one longitudinal spline of the drive member 40 engages a corresponding track of the piston rod 30.

[0092] The final dose nut 50 is located between the dose setting member 60 and the drive member 40. It is rotationally constrained to the dose setting member 60 via a spline interface. When relative rotation occurs only between the dose setting member 60 and the drive member 40 during dialing, the final dose nut moves along a helical path relative to the drive member 40 via a threaded interface. As an alternative, the nut 50 can be spline-connected to the drive member 40 and thread-connected to the dose setting member 60. A final dose stop is provided on the nut 50 to engage the stop of the drive member 40 when the set dose corresponds to the remaining dispensable drug dose in the reservoir 100.

[0093] The dose indicator or dose setting member 60 is a tubular element. The dose setting member 60 rotates during dose setting (via the dose selector 80) and dose correction and during dose dispensing by the torsion spring 90. The dose setting member 60 and the metering element 110 together define a zero position ("rest") and a maximum dose position. Thus, the dose setting member 60 can be regarded as a dose setting member.

[0094] For manufacturing reasons, the dose setting member 60 of the embodiment shown in the figure includes a lower dose setting member 60a, which is rigidly fixed to the upper dose setting member 60b during assembly to form the dose setting member 60. The lower dose setting member 60a and the upper dose setting member 60b are separate components only for simplifying the molding and assembly of the dose setting member 60. As an alternative, the dose setting member 60 can be an integral part. The dose setting member 60 is constrained to the housing 10 by snap-fit to allow rotation but not translation. The dose setting member 60 includes an annular recess or groove near its distal end, which engages a corresponding bead on the inner surface of the housing 10. The lower dose setting member 60a is marked with a series of numbers, which are visible through the metering element 110 and the openings 11a, 11b in the housing 10 to indicate the dialed dose of the medicament.

[0095] Further, the lower part 60a of the dose setting member has a portion with an external thread that engages the metering element 110. An end stop is provided at the opposite end of the thread to limit relative movement with respect to the metering element 110.

[0096] An adapter feature in the form of a splined ring is provided on the upper part 60b of the dose setting member and is directed inwards for splined engagement with the splines of the button 70 during dose setting and dose correction. A click arm is provided on the outer surface of the dose setting member 60, which click arm interacts with the drive member 40 and the metering member 110 to generate a feedback signal. Further, the lower part 60a of the dose setting member is rotationally constrained to the nut 50 and the adapter plate 120 via a spline interface including at least one longitudinal spline. Further, the lower part 60a of the dose setting member includes an interface for attaching the torsion spring 90.

[0097] The button 70 forming the proximal end of the device is permanently splined to the dose selector 80. A central rod extends distally from the proximal actuating face of the button 70. The rod is provided with a flange that bears splines for splined engagement with the upper part 60b of the dose setting member. Thus, when the button 70 is not pressed, the rod is also splined to the upper part 60b of the dose setting member via the splines, but when the button 70 is pressed, this spline interface is disconnected. The button 70 has a splined discontinuous annular skirt. When the button 70 is pressed, the splines on the button 70 engage the splines on the housing 10, thereby preventing the button 70 (and thus the dose selector 80) from rotating during dispensing. When the button 70 is released, these splines disengage, thereby allowing the dose to be dialed. Further, a ratchet tooth ring is provided on the inner side of the button flange for interaction with the adapter plate 120.

[0098] The dose selector 80 is axially constrained to the housing 10. It is rotationally constrained to the button 70 via a spline interface. This spline interface (which includes grooves that interact with the spline features formed by the annular skirt of the button 70) remains engaged regardless of the axial position of the dose button 70. The dose selector 80 or the dose dial grip is a sleeve-shaped member with a serrated outer skirt.

[0099] The torsion spring 90 is attached at its distal end by a hook 91 to the insert 12 and thus to the housing 10, and at the other end to the dose setting member 60. The torsion spring 90 is located inside the dose setting member 60 and surrounds the distal part of the drive member 40. The torsion spring 90 is pre-wound during assembly such that when the mechanism is at zero unit dialing, the torsion spring applies a torque to the dose setting member 60. The rotational movement of the dose selector 80 for setting the dose causes the dose setting member 60 to rotate relative to the housing 10 and further energizes the torsion spring 90.

[0100] The reservoir 100 is received within the reservoir unit body 20. The reservoir 100 can be a glass ampoule having a removable rubber stopper at its proximal end. The distal end of the reservoir 100 is provided with a pierceable rubber seal which is held in place by a curled annular metal band. In the depicted embodiment, the reservoir 100 is a standard 1.5 ml reservoir. The device is designed to be disposable as the reservoir 100 cannot be replaced by the user or a healthcare professional. However, a reusable variant of the device can be provided by making the reservoir unit body 20 removable and allowing for the rearward winding of the piston rod 30 and resetting of the nut 50.

[0101] The metering element 110 is constrained against rotation but is allowed to translate axially relative to the housing 10 via a spline interface. The metering element 110 has helical features on its inner surface which engage helical thread cutouts in the dose setting member 60 such that rotation of the dose setting member 60 causes axial translation of the metering element 110. Such helical features on the metering element 110 also form a stop base against the helical cutout ends in the dose setting member 60, thereby limiting the minimum and maximum doses that can be set.

[0102] The metering element 110 has a generally plate-like or strip-like member having a central aperture or window and two flanges extending on either side of the aperture. The flanges are preferably opaque and thus shield or cover the dose setting member 60, while the aperture or window allows a portion of the lower part 60a of the dose setting member to be viewed. Further, the metering element 110 has a cam and a recess which interact with the actuator arm of the dose setting member 60 at the end of dose dispensing.

[0103] The adapter plate 120 is an annular member. The adapter plate 120 is spline-connected to the dose setting member 60 via a spline. It is also coupled to the drive member 40 via a ratchet interface. The ratchet provides detent positions corresponding to each dose unit between the dose setting member 60 and the drive member 40 and engages different helical angles during relative rotation in the clockwise and counterclockwise directions. An actuator arm is provided on the adapter plate 120 for interaction with the ratchet features of the button 70.

[0104] The adapter spring 130 is a compression spring. The axial positions of the drive member 40, the adapter plate 120, and the button 70 are defined by the action of the adapter spring 130, which applies a force on the drive member 40 in the proximal direction. This spring force reacts via the drive member 40, the adapter plate 120, and the button 70, and when "at rest", the spring force further reacts through the dose selector 80 to the housing 10. The spring force ensures that the ratchet interface between the drive member 40 and the adapter plate 120 is always engaged. In the "at rest" position, it also ensures that the button spline engages with the dose setting member spline, and the drive member teeth engage with the teeth of the housing 10.

[0105] The bearing 140 is axially constrained to the piston rod 30 and acts on the plug within the liquid medicament reservoir. It is axially clamped to the piston rod 30 but free to rotate.

[0106] In the case where the device is in the "at rest" condition as shown in Figure 1 and FIG. 3a, the dose setting member 60 is positioned with the metering element 110 against its zero-dose base, and the button 70 is not depressed. The dose mark "0" on the dose setting member 60 is visible through the window 11b of the housing 10 and the metering element 110, respectively.

[0107] The torsion spring 90 (which has a plurality of pre-wound turns applied to it during the assembly of the device) applies a torque to the dose setting member 60 and prevents rotation via the zero-dose base.

[0108] The user selects a variable dose of liquid medicament by rotating the dose selector 80 clockwise, which results in the same rotation in the dose setting member 60. The rotation of the dose setting member 60 causes the charging of the torsion spring 90, thereby increasing the energy stored therein. As the dose setting member 60 rotates, the metering element 110 axially translates due to its threaded engagement, thereby displaying the value of the dialed dose. The metering element 110 has flanges on either side of the window area, which cover the digits adjacent to the dialed dose printed on the dose setting member 60 to ensure that only the set dose digits are visible to the user.

[0109] A specific feature of the present disclosure is that it includes a visual feedback feature in addition to the discrete dose digit display typical on this type of device. The distal end of the metering element 110 creates a sliding scale visible through the small window 11a in the housing 10. As an alternative, the sliding scale can be formed using a separate component that engages with the dose setting member 60 on a different helical track.

[0110] When the user sets the dose, the metering element 110 translates axially, and the distance of movement is proportional to the set dose value. This feature provides the user with clear feedback regarding the approximate magnitude of the set dose. The dispensing speed of the auto-injector mechanism can be higher than that of a manual syringe device, so it may not be possible to read the digital dose display during dispensing. During dispensing, the metering feature provides the user with feedback regarding the dispensing progress without having to read the dose digits themselves. For example, the metering display can be formed by an opaque element on the metering element 110, thereby revealing a contrasting colored component below. Alternatively, the element that can be revealed can be printed with approximate dose digits or other indices to provide a more precise resolution. In addition, the metering display mimics the action of the syringe barrel during dose setting and dispensing.

[0111] Since the splined teeth of the drive member engage the teeth of the housing 10, rotation of the drive member 40 is prevented during dose setting and rotation of the dose setting member 60. Therefore, relative rotation must occur between the adapter plate 120 and the drive member 40 via the ratchet interface.

[0112] The user torque required to rotate the dose selector 80 is the sum of the torque required to wind the torsion spring 90 and the torque required to service the ratchet interface. The adapter spring 130 is designed to provide an axial force to the ratchet interface and bias the adapter plate 120 onto the drive member 40. This axial load serves to maintain the engagement of the ratchet teeth of the adapter plate 120 and the drive member 40. The torque required to service the ratchet in the dose setting direction is a function of the axial load applied by the adapter spring 130, the clockwise rake angle of the ratchet teeth, the coefficient of friction between the mating surfaces, and the mean radius of the ratchet interface.

[0113] When the user rotates the dose selector 80 enough to increment the mechanism by one increment, the dose setting member 60 rotates one ratchet tooth relative to the drive member 40. At this time, the ratchet teeth re-engage into the next detent position. The re-engagement of the ratchet produces an audible click, and the change in the required torque input gives a tactile feedback.

[0114] Relative rotation between the dose setting member 60 and the drive member 40 is allowed. This relative rotation also causes the final dose nut 50 to travel along its threaded path towards its final dose seat on the drive member 40.

[0115] In the absence of a user torque being applied to the dose selector 80, the dose setting member 60 is now prevented from rotating back under the torque applied by the torsion spring 90 solely by the ratchet interface between the adapter plate 120 and the drive member 40. The torque required to service the ratchet in the counterclockwise direction is a function of the axial load applied by the adapter spring 130, the counterclockwise ramp angle of the ratchet, the coefficient of friction between the mating surfaces, and the mean radius of the ratchet features. The torque required to service the ratchet must be greater than the torque applied by the torsion spring 90 to the dose setting member 60 (and thus the adapter plate 120). Accordingly, the ratchet ramp angle is increased in the counterclockwise direction to ensure this, while ensuring that the dialing torque is as low as possible.

[0116] Now, the user can choose to increase the selected dose by continuing to rotate the dose selector 80 in the clockwise direction. For each dose increment, the process of servicing the ratchet interface between the dose setting member 60 and the drive member 40 is repeated. For each dose increment, additional energy is stored within the torsion spring 90, and an audible and tactile feedback is provided for each increment dialed by the re-engagement of the ratchet teeth. The torque required to rotate the dose selector 80 increases as the torque required to wind the torsion spring 90 increases. Accordingly, the torque required to service the ratchet in the counterclockwise direction must be greater than the torque applied by the torsion spring 90 to the dose setting member 60 when the maximum dose has been reached.

[0117] If the user continues to increase the selected dose until the maximum dose limit is reached, the dose setting member 60 engages its maximum dose abutment on the maximum dose abutment of the metering element 110. This prevents further rotation of the dose setting member 60, the adapter plate 120, and the dose selector 80.

[0118] Depending on how many drug unit increments the mechanism has delivered, during dose selection, the final dose nut 50 can bring its final dose abutment into contact with the stop surface of the drive member 40. The abutment prevents further relative rotation between the dose setting member 60 and the drive member 40, and thus limits the dose that can be selected. The position of the final dose nut 50 is determined by the total number of relative rotations that have occurred between the dose setting member 60 and the drive member 40 each time the user sets a dose.

[0119] In the case where the mechanism is in a state of a selected dose, the user can deselect any number of increments from this dose. The deselection of the dose is achieved by the user rotating the dose selector 80 counterclockwise. The torque applied by the user to the dose selector 80, when combined with the torque applied by the torsion spring 90, is sufficient to overhaul the ratchet interface between the adapter plate 120 and the drive member 40 in the counterclockwise direction. When overhauling the ratchet, a counterclockwise rotation occurs in the dose setting member 60 (via the adapter plate 120), which causes the dose setting member 60 to return towards the zero dose position and releases the torsion spring 90. The relative rotation between the dose setting member 60 and the drive member 40 causes the final dose nut 50 to return away from the final dose base along its helical path.

[0120] In the case where the mechanism is in a state of a selected dose, the user can activate the mechanism to start the delivery of the dose. The delivery of the dose is initiated by the user axially pressing down the button 70 in the distal direction (Figure 3b).

[0121] When the button 70 is pressed down, the splines between the button 70 and the dose setting member 60 disengage, thereby disconnecting the button 70 and the dose selector 80 from the delivery mechanism (i.e., from the dose setting member 60, the metering element 110, and the torsion spring 90) rotationally. The splines on the button 70 engage with the splines on the housing 10, thereby preventing the button 70 (and thus the dose selector 80) from rotating during dispensing. Since the button 70 is stationary during dispensing, it can be used in the dispensing response mechanism. The stop feature in the housing 10 limits the axial travel of the button 70 and reacts to any axial abuse load applied by the user, thereby reducing the risk of damaging internal components.

[0122] The adapter plate 120 and the drive member 40 travel axially with the button 70. This engages the splined tooth interface between the drive member 40 and the dose setting member 60, thereby preventing relative rotation between the drive member 40 and the dose setting member 60 during dispensing. The splined tooth interface 18, 41 between the drive member 40 and the housing insert 12 disengages, so the drive member 40 can now rotate and is driven by the torsion spring 90 via the dose setting member 60 and the adapter plate 120.

[0123] The rotation of the drive member 40 causes the piston rod 30 to rotate due to its splined engagement, and then the piston rod 30 advances due to its threaded engagement with the housing 10. The rotation of the dose setting member 60 also causes the metering element 110 to axially travel back to its zero position, whereby the zero dose base stops the mechanism.

[0124] Tactile feedback during dose dispensing is provided via a compliant cantilevered clicker arm integrated into the adapter plate 120. This arm radially interfaces with a ratchet feature on the inner surface of the button 70, whereby the ratchet tooth spacing corresponds to the rotation of the dose setting member 60 required for a single incremental dispensing. During dispensing, as the dose setting member 60 rotates and the button 70 is rotationally coupled to the housing 10, the ratchet feature engages the clicker arm to produce an audible click as each dose increment is delivered.

[0125] As the user continues to depress the button 70, dose delivery continues via the mechanical interaction described above. If the user releases the button 70, the clutch spring 130 returns the drive member 40 to its "rest" position (along with the clutch plate 120 and button 70), engaging the splines between the drive member 40 and the housing 10, preventing further rotation and stopping dose delivery.

[0126] During dose delivery, the drive member 40 and the dose setting member 60 rotate together so that no relative movement occurs in the last-dose nut 50. Hence, the last-dose nut 50 travels axially relative to the drive member 40 only during dialing.

[0127] Once dose delivery has ceased, the user may release the button 70 by returning the dose setting member 60 to the zero dose station, which will re-engage the spline teeth between the drive member 40 and the housing 10. The mechanism now returns to the "rest" condition.

[0128] Additional audible feedback in the form of a "click" is provided at the end of dose dispensing (different from the "click" provided during dispensing) to inform the user that the device has returned to its zero position through the interaction of the snap arm on the dose setting member 60 with the ramp on the drive member 40 and the cam and recess on the metering element 110. This embodiment allows feedback to be generated only at the end of dose delivery, and no feedback is generated if the device is dialed back to or away from the zero position.

[0129] Figure 6a 、 Figure 6b 、 Figure 7a and Figure 7b Schematic cross-sectional views of regions of the mechanism unit of a drug delivery device are shown for various alternative embodiments of the drive member 40 in combination with the piston rod 30 and the adapter spring 130. These embodiments allow for exact adjustment of the position of the piston rod 30 relative to the housing 10 prior to final assembly of the drug delivery device. The device may be the one described further above. Thus, Figure 1 The features described in Figures 5 to 5 may be used in the embodiments described below. The drug delivery device may be disposable, or it may be reusable. Figure 6a 、 Figure 6b 、 Figure 7a, Figure 7b , Figure 9a , Figure 9b , Figure 9c , Figure 9d , Figure 10a , Figure 10b , Figure 10c and Figure 10d In embodiments of, the mechanism unit includes a housing 10, a piston rod 30, and a dose setting and driving mechanism, wherein the piston rod 30 is movably held in the housing 10, and the dose setting and driving mechanism is configured to perform a dose setting operation for setting a dose to be delivered and a dose delivery operation for delivering the set dose by transmitting a delivery force to the piston rod 30 so as to drive the piston rod 30 in a distal direction relative to the housing 10 during the dose delivery operation.

[0130] As used herein, the terms "distal" and "proximal" may refer to opposite axial directions or ends. "Distal" may refer to the direction towards an end of a component of the dispensing end or the drug delivery device, which end is or is to be arranged closest to the reservoir 100, the reservoir unit body 20, or the dispensing end of the drug delivery device. "Proximal" may refer to the direction away from the dispensing end or an end, which end is or is to be arranged further away from the reservoir 100, the reservoir unit body 20, or the dispensing end of the drug delivery device. Additionally, the distal direction may be away from the proximal end. The proximal direction may be away from the distal end.

[0131] The dose setting and driving mechanism includes a driving member 40 and an adapter mechanism. Compared with the previously described configuration that is integral with the driving member, Figure 6a , Figure 6b , Figure 7a , Figure 7b , Figure 9a , Figure 9b , ​ , ​ , ​ , ​ , ​ and ​ the driving member 40 in embodiments of is a two-part component including a first driving member 40a and a second driving member 40b. The piston rod 30 is movable relative to the housing 10, for example, movably held in the housing 10 (not shown in ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ and ​ ). The first driving member 40a is due to the lock 44 (such as​ , ​ , ​ , ​ , ​ and ​ shown) or a threaded guide 45 (such as ​ , ​ , ​ and ​ shown) directly mechanically cooperate with the piston rod 30 to transmit force to the piston rod 30, wherein the lock 44 and the threaded guide 45 can be integral parts of the first drive member 40a. The first drive member 40a is axially fastened and rotatable relative to the housing 10, wherein rotation of the first drive member 40a relative to the housing 10 in the delivery direction causes movement of the piston rod 30 in the distal direction, and rotation in the direction opposite to the delivery direction causes proximal movement of the piston rod 30. The second drive member 40b is arranged to be mechanically, preferably directly, coupled to the first drive member 40a to transmit the delivery force to the first drive member 40a. As ​ , ​ , ​ , ​ , ​ and ​ of the embodiment shown, the first drive member 40a can be splined to the piston rod, and the piston rod can be threadedly coupled to the housing. Alternatively, as ​ , ​ , ​ and ​ shown, the first drive member 40a can be threadedly coupled to the piston rod, and the piston rod can be splined to the housing.

[0132] The adapter mechanism includes an adapter spring 130. The distal end of the adapter spring 130 rests on the first drive member 40a and the proximal end of the adapter spring 130 rests on the second drive member 40b, such that axial movement of the second drive member 40b relative to the first drive member 40a in the distal direction can only occur against the resistance of the spring force of the adapter spring 130. The adapter mechanism has at least two different states: a delivery state, in which the adapter spring 130 is compressed (see ​ , ​ , ​ and ​ ); and a set state, in which the adapter spring 130 is compressed less than in the delivery state (see ​ , ​ , ​ and ​ ).

[0133] In the set state, the second drive member 40b is rotationally fastened relative to the housing 10 at least against rotation in the delivery direction. The second drive member 40b can be in a state where it is​ is fastened in a rotationally fixed manner relative to the housing 10 in the same way as the one-piece drive member 40 described with reference to FIGS. 1 to 5. However, in the set state, it is also conceivable that the second drive member 40b is fastened in a rotationally fixed manner relative to the housing 10 against rotation in the delivery direction and in the direction opposite to the delivery direction. In the delivery state, the second drive member 40b can rotate relative to the housing 10 in the delivery direction, wherein in the set state, the first drive member 40a can rotate relative to the second drive member 40b and the housing 10 at least in the delivery direction, and wherein in the delivery state, the second drive member 40b is rotationally locked to the first drive member 40a at least against rotation of the second drive member 40b relative to the first drive member 40a in the delivery direction. However, in the delivery state, it is also conceivable that the second drive member 40b is rotationally locked to the first drive member 40a against rotation of the second drive member 40b relative to the first drive member 40a in the delivery direction and in the direction opposite to the delivery direction.

[0134] The mechanism unit is configured to be connected to a reservoir unit including a reservoir 100 and a reservoir unit body 20 for assembling the two units. The first drive member 40a is accessible from the outside of the housing 10 for operation such that in the set state, the position of the piston rod 30 relative to the housing 10 is adjustable by rotation of the first drive member 40a before connection of the mechanism unit and the reservoir unit. This accessibility can be via either or both of the distal and proximal ends of the housing 10. However, it is also conceivable that the first drive member 40a is accessible from the outside of the housing 10 before the drug delivery device is fully assembled and after connection of the mechanism unit and the reservoir unit. In this case, the first drive member 40a can be accessed via an opening from the proximal end of the housing 10, which opening is closed by a button 70 during final assembly of the drug delivery device. It goes without saying that this opening can also be used to manipulate the first drive member 40a before the mechanism unit is connected to the reservoir unit.

[0135] In ​ 、 ​ 、 ​ 、 ​ 、 ​ 、 ​ 、 ​ 、 ​ 、 ​ 、 ​ 、 ​ and ​ in the embodiments of ​ 、 ​ 、 ​ and ​ shown, the second drive member 40b can move axially relative to the first drive member 40a and the housing 10, for example, in the distal direction, for use in a set state as shown in​ , ​ , ​ and ​ switch between the delivery states shown. Further, in the set and delivery states, the first drive member 40a is secured against proximal and distal movement relative to the housing 10.

[0136] The first drive member 40a is engaged to the piston rod 30, and the piston rod 30 is engaged to the housing 10. In ​ , ​ , ​ , ​ , ​ and ​ embodiments, due to the lock 44, the first drive member 40a is directly splined to the piston rod 30, and the piston rod 30 is threadedly engaged to the housing 10. In such a case, rotational movement of the first drive member 40a relative to the piston rod 30 is not possible in the set and delivery states.

[0137] As ​ , ​ , ​ and ​ shown, the first drive member 40a includes a first locking feature 42, and the second drive member 40b includes a second locking feature 43. The first locking feature 42 is non-rotatable and axially non-movable relative to the first drive member 40a, and the second locking feature 43 is non-rotatable and axially non-movable relative to the second drive member 40b. The first locking feature 42 can be an integral part of the first drive member 40a, and the second locking feature 43 can be an integral part of the second drive member 40b. As ​ and ​ shown, in the delivery state, the first locking feature 42 engages with the second locking feature 43.

[0138] ​ and ​ show embodiments of the mechanism unit where, in the set state, the first locking feature 42 and the second locking feature 43 are disengaged.

[0139] ​Shows the mechanism unit in the set state. In this state, the adapter spring 130 is relaxed, and the first drive member 40a is not engaged with the second drive member 40b. Due to the separate connection of the first locking feature 42 and the second locking feature 43, the first drive member 40a and the piston rod 30 can rotate relative to the second drive member 40b in the delivery direction and in the direction opposite to the delivery direction. This enables the piston rod 30 to be axially moved in the proximal and distal directions with the help of the first drive member 40a, thereby allowing the distance between the proximal end of the plug and the distal end of the piston rod 30 to be adjusted individually. In this state, the second drive member 40b is non-rotatably movable relative to the housing 10.

[0140] ​ Shows the mechanism unit in the delivery state according to the same embodiment as ​ shown. In this state, due to pressing the button 70, the second drive member 40b is axially displaced in the distal direction. This causes the adapter spring 130 to be compressed and the first locking feature 42 to engage with the second locking feature 43. Due to the resulting connection between the first locking feature 42 and the second locking feature 43, the first drive member 40a is non-movable relative to the second drive member 40b in the delivery direction and in the direction opposite to the delivery direction. Thus, rotation of the second drive member 40b causes rotation of the first drive member 40a, whereby the piston rod 30 is axially displaced in the distal direction so as to enable dispensing of the drug from the reservoir 100. After pressing the button 70, in the set mode, the spring force of the adapter spring 130 causes the second drive member 40b to move back to its original position.

[0141] In ​ and ​ the embodiment shown, the first locking feature 42 is designed as a circumferential outer ring on the outer circumferential surface at the proximal end of the first drive member 40a, and the second locking feature 43 is arranged as a circumferential inner ring on the inner circumferential surface at the distal end of the second drive member 40b. These two rings have locking wedges that are complementary to each other. In the set mode, these locking wedges are pushed into each other in the axial direction such that relative rotational movement between the first locking feature 42 and the second locking feature 43 is not possible.

[0142] The locking wedge of the second locking feature 43 can be tapered at its distal end. Additionally or alternatively, the locking wedge of the first locking feature 42 can be tapered at its proximal end. The tapered portion is designed to facilitate insertion of the second locking feature 43 into the first locking feature 42 during the transition from the set state to the delivery state.

[0143] ​ and ​The illustrated embodiment is particularly advantageous because it allows the axial position of the piston rod 30 to be changed in the distal and proximal directions in the set state.

[0144] ​ and ​ An alternative embodiment of the mechanism unit is shown, in which the first locking feature 42 engages with the second locking feature 43 in the set state (see ​ ) and in the delivery state (see ​ ).

[0145] In this case, the first locking feature 42 and the second locking feature 43 are configured such that if the first locking feature 42 engages with the second locking feature 43, the first locking feature 42 can rotate relative to the second locking feature 43 in the delivery direction and is turnably fastened relative to the second locking feature 43 in the direction opposite to the delivery direction. The first locking feature 42 is designed as a circumferential outer ring on the outer circumferential surface at the proximal end of the first drive member 40a, and the second locking feature 43 is arranged as a circumferential inner ring on the inner circumferential surface at the distal end of the second drive member 40b. These two rings have complementary serrated wedges (see ​ ), which allow the first drive member 40a to rotate relative to the second drive member 40b in the delivery direction in the set mode and the delivery mode, and prevent the first drive member 40a from rotating relative to the second drive member 40b in the direction opposite to the delivery direction.

[0146] As ​ shown, the first locking feature 42 or / and the second locking feature 43 is / are made elastic so that when the first locking feature 42 moves in the delivery direction D, the serrated wedge of the first locking feature 42 can slide on the serrated wedge of the second locking feature 43. However, in this case, it is impossible for the serrated wedge of the first locking feature 42 to slide on the serrated wedge of the second locking feature 43 in the direction opposite to the delivery direction D. Therefore, in this case, the movement of the serrated wedge of the second locking feature 43 of the second drive member 40b in the delivery direction D inevitably causes the movement of the serrated wedge of the first locking feature 42 of the first drive member 40a in the delivery direction D. It should be noted that in order to achieve the above effects, other interlocking mechanisms between the first locking feature 42 and the second locking feature 43 are also possible. For example, it is conceivable to use other ratchet connectors or use pawls.

[0147] Due to the serrated connection, as ​ , ​ and ​ shown, it is not necessary to release the first drive member 40a of the second drive member 40b in the set mode in order to axially displace the piston rod 30 in the distal direction by means of the rotational movement of the first drive member 40a. Thus, compared with​ and ​ Contrary to the embodiment of, the insertion step of the first locking feature 42 relative to the second locking feature 43 can be avoided during the transition from the setting mode to the delivery mode. Further, after the desired distance between the proximal end of the setting plug and the distal end of the piston rod 30 is set, the serrated connection prevents axial displacement of the piston rod 30 in the proximal direction, since rotational movement of the first drive member 40a in a direction opposite to the delivery direction is not possible.

[0148] However, it should be noted that it is also conceivable that ​ and ​ the first locking feature 40a and the second locking feature 40b of the embodiment of can be made into a serrated connection.

[0149] As in ​ and ​ in the embodiment of, in ​ and ​ in the embodiment of, the second drive member 40b is rotationally locked relative to the housing 10 in the set state and is rotationally movable in the delivery state.

[0150] ​ , ​ , ​ , ​ and ​ , ​ , ​ , ​ each shows a further embodiment of the two-part drive member 40 of the mechanism unit for a drug delivery device according to the present invention, wherein ​ , ​ , ​ and ​ show longitudinal cross-sectional views, and ​ , ​ , ​ and ​ show cross-sectional views of the drive member 40. The drug delivery device can be the drug delivery device further described above. Thus, ​ to the features described in FIGS. 5 can be used for the embodiments described below. The drive member 40 includes a first drive member 40a and a second drive member 40b, wherein the first drive member 40a includes a first locking feature 42 and the second drive member 40b includes a second locking feature 43. The first locking feature 42 is rotationally and axially immovable relative to the first drive member 40a, and the second locking feature 43 is rotationally and axially immovable relative to the second drive member 40b. The first locking feature 42 can be an integral part of the first drive member 40a, and the second locking feature 43 can be an integral part of the second drive member 40b. In the delivery state (see​ and ​ ) and in a set state (see ​ and ​ ), the first locking feature 42 engages with the second locking feature 43. ​ , ​ , ​ , ​ and ​ , ​ , ​ , ​ The embodiments of ​ , ​ , ​ and ​ differ only in that the first drive member 40a of ​ , ​ , ​ and ​ is splined to the piston rod 30, and the piston rod 30 is threadedly coupled to the housing 10, while

[0151] ​ shows ​ , ​ , ​ , ​ and ​ , ​ , ​ , ​ the outer surface of the first drive member 40a of the embodiments of

[0152] As ​ and ​ shown, the first locking portion 42a cannot rotate relative to the second locking feature 43, so in the delivery state, the first drive member 40a cannot rotate relative to the second drive member 40b. This is achieved by selecting the height of the first locking portion 42a such that the recess formed by the second locking feature 43 is almost completely filled by the first locking portion 42a.

[0153] As ​ and ​ shown, the height of the second locking part 42b is such that the recess of the second locking feature 43 is only partially filled by the second locking part 42b. Thus, in the setting mode, the second locking part 42b can slide on the second locking feature 43 with the help of an external force. Therefore, in the setting mode, the first drive member 40a can be rotated relative to the second drive member 40b. However, due to the height of the second locking part 42b, the second locking part 42b preferably cannot slide on the second locking feature 43 without the help of an external force. This prevents the loss of the completed setting in the set state. In addition, by sliding the second locking part 42b on the second locking feature 43, acoustic or tactile feedback can be generated during the adjustment process.

[0154] In ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ and ​ embodiments, the first locking feature 42 and the second locking feature 43 are designed such that when the first locking feature 42 engages with the second locking feature 43, the first drive member 40a occupies one of a number of stable positions relative to the second drive member 40b. Preferably, these stable positions are defined by the respective relative distances between adjacent locking wedges. The angular distance between the stable positions can be adjusted to the angle at which the user must rotate the dose setting member to set the minimum dose that can be delivered by the drug delivery device. This dose can correspond to a unit increment. In addition, the distance between the stable positions can be such that the movement of the first drive member 40a relative to the second drive member 40b from one stable position to the next adjacent stable position results in an axial movement of the piston rod 30 that corresponds to the axial movement of the piston rod 30 during the delivery of a unit increment of the dose. It is also conceivable to design the locking features 42 and 43 such that the movement of the first drive member 40a relative to the second drive member 40b from one stable position to the next adjacent stable position results in an axial movement of the piston rod 30 that would correspond to the axial movement of the piston rod 30 during the delivery of less than a unit increment (e.g., one-half or one-quarter of a unit increment).

[0155] In the case where the first locking feature 42 does not engage with the second locking feature 43 in the setting mode, such as in ​ and ​In an embodiment, the transition from the set state to the delivery state should ensure that the locking wedges of the locking features 42 and 43 are not jammed, which may impede the axial displacement of the second drive member 40b in the distal direction. Thus, it may be advantageous that the first drive member 40a is designed such that, after a rotational movement relative to the second drive member 40b, the first drive member 40a comes to rest relative to the second drive member 40b only in a position corresponding to one of these stable positions, i.e., a position where the locking wedges can interlock reliably. For example, the first drive member 40a may be rotated relative to the second drive member 40b only stepwise.

[0156] In ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ and ​ In embodiments of, the dose setting and driving mechanism includes a dose setting member 60 which is movable relative to the housing 10 from an initial position to a dose setting position in the set state to set the dose of the drug. The dose setting member 60 is rotationally constrained relative to the second drive member 40b in the delivery state and is rotatable relative to the second drive member 40b in the set state. The first drive member 40a may be rotationally constrained relative to the dose setting member 60 and the second drive member 40b in a direction opposite to the delivery direction in the delivery state. In addition, the first drive member 40a may be rotatable relative to the dose setting member 60 and the second drive member 40b in the delivery direction in the delivery state. The first drive member 40a may be rotatable relative to the dose setting member 60 and the second drive member 40b in the delivery direction in the set state. In addition, the first drive member 40a may be rotatable relative to the dose setting member 60 and the second drive member 40b in the delivery direction and in a direction opposite to the delivery direction in the set state.

[0157] Comprising ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ , ​ and ​The production of a drug delivery device according to an embodiment of the present invention starts with providing a reservoir unit and a mechanism unit. The reservoir unit includes a reservoir 100 containing a drug, wherein a stopper is movably held in the reservoir 100, and wherein the reservoir 100 is held in a reservoir unit body 20.

[0158] Thereafter, the stopper position of the stopper relative to the reservoir unit body 20 is determined. In addition, a desired piston rod position of the piston rod 30 relative to the housing 10 is determined based on the determined stopper position. The desired piston rod position is determined such that, if the mechanism unit and the reservoir unit are connected, the piston rod 30 and the stopper are arranged at a predetermined distance relative to each other. In addition, a specific displacement distance by which the piston rod 30 must be displaced relative to the housing 10 in the distal direction to be in the desired piston rod position is determined. The predetermined distance between the piston rod 30 and the stopper is the distance that allows the delivery of the exact dose set by the user during the first actuation of the drug delivery device after the device is assembled.

[0159] Subsequently, in the set state of the mechanism unit, the first drive member 40a is rotated relative to the second drive member 40b to displace the piston rod 30 relative to the housing by the specific displacement distance. Finally, the reservoir unit and the mechanism unit are connected to each other.

[0160] However, it should be noted that the rotation of the first drive member 40a relative to the second drive member 40b to displace the piston rod 30 relative to the housing by the specific displacement distance can also be completed after the reservoir unit and the mechanism unit are connected to each other and before the drug delivery device is fully assembled. As mentioned above, in this case, the first drive member 40a can be accessed via an opening from the proximal end of the housing 10, and the opening is closed by a button 70 during the final assembly of the drug delivery device after the appropriate piston rod position has been achieved.

[0161] The terms "drug" or "pharmaceutical agent" are used synonymously herein and describe a pharmaceutical formulation that contains one or more active pharmaceutical ingredients or pharmaceutically acceptable salts or solvates thereof and optionally a pharmaceutically acceptable carrier. In the broadest sense, an active pharmaceutical ingredient ("API") is a chemical structure that has a biological effect on a human or an animal. In pharmacology, drugs or pharmaceutical agents are used to treat, cure, prevent or diagnose diseases or to otherwise enhance physical or mental health. Drugs or pharmaceutical agents can be used for a limited period or regularly for chronic diseases.

[0162] As described below, a medicament or pharmaceutical agent may comprise at least one API or a combination thereof in various types of formulations for the treatment of one or more diseases. Examples of APIs may include small molecules (having a molecular weight of 500 Da or less); polypeptides, peptides, and proteins (e.g., hormones, growth factors, antibodies, antibody fragments, and enzymes); carbohydrates and polysaccharides; and nucleic acids, double-stranded or single-stranded DNA (including naked DNA and cDNA), RNA, antisense nucleic acids (such as antisense DNA and RNA), small interfering RNA (siRNA), ribozymes, genes, and oligonucleotides. Nucleic acids can be incorporated into molecular delivery systems (such as vectors, plasmids, or liposomes). A mixture of one or more medicaments is also contemplated.

[0163] The medicament or pharmaceutical agent can be contained in a primary packaging or “drug container” suitable for use with a drug delivery device. The drug container can be, for example, a reservoir, syringe barrel, cartridge, or other rigid or flexible vessel configured to provide a suitable chamber for storing (e.g., short-term or long-term storage) one or more medicaments. For example, in some cases, the chamber can be designed to store the medicament for at least one day (e.g., 1 day to at least 30 days). In some cases, the chamber can be designed to store the medicament for about 1 month to about 2 years. Storage can be at room temperature (e.g., about 20 °C) or refrigerated temperature (e.g., from about -4 °C to about 4 °C). In some cases, the drug container can be or can include a dual-chamber reservoir configured to separately store two or more components of a pharmaceutical formulation to be administered (e.g., an API and a diluent, or two different medicaments), with one component stored in each chamber. In such cases, the two chambers of the dual-chamber reservoir can be configured to allow mixing between the two or more components before and / or during dispensing into a human or animal body. For example, the two chambers can be configured such that they are in fluid communication with each other (e.g., by means of a conduit between the two chambers) and allow the user to mix the two components before dispensing when needed. Alternatively or additionally, the two chambers can be configured to allow mixing when the components are dispensed into a human or animal body.

[0164] The drugs or medicaments comprised in the drug delivery device described herein can be used for treating and / or preventing many different types of medical disorders. Examples of disorders include, for example, diabetes or diabetes-related complications (such as diabetic retinopathy), thromboembolic disorders (such as deep vein or pulmonary thromboembolism). Further examples of disorders are acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and / or rheumatoid arthritis. Examples of APIs and drugs are those described in manuals such as the German Medical Association Drug Handbook (Rote Liste) 2014, for example, but not limited to, main group 12 (antidiabetic drugs) or 86 (oncological drugs); and the 15th edition of the Merck Index.

[0165] Examples of APIs for treating and / or preventing type 1 or type 2 diabetes or diabetes-related complications of type 1 or type 2 diabetes include insulin (e.g., human insulin, or human insulin analogues or derivatives); glucagon-like peptide (GLP-1), GLP-1 analogues or GLP-1 receptor agonists, or their analogues or derivatives; dipeptidyl peptidase-4 (DPP4) inhibitors, or pharmaceutically acceptable salts or solvates thereof; or any mixture thereof. As used herein, the terms “analogue” and “derivative” refer to a polypeptide having a molecular structure that can be formally derived from the structure of a naturally occurring peptide (e.g., the structure of human insulin) by deletion and / or exchange of at least one amino acid residue present in the naturally occurring peptide and / or by addition of at least one amino acid residue. The added and / or exchanged amino acid residues can be encoded amino acid residues or other naturally occurring residues or purely synthetic amino acid residues. Insulin analogues are also referred to as “insulin receptor ligands”. In particular, the term “derivative” refers to a polypeptide having a molecular structure that can be formally derived from the structure of a naturally occurring peptide (e.g., the structure of human insulin), wherein one or more organic substituents (such as fatty acids) are bound to one or more amino acids. Optionally, one or more amino acids present in the naturally occurring peptide may have been deleted and / or replaced by other amino acids (including non-encoded amino acids), or amino acids (including non-encoded amino acids) have been added to the naturally occurring peptide.

[0166] Examples of insulin analogs are Gly(A21), Arg(B31), Arg(B32) human insulin (insulin glargine); Lys(B3), Glu(B29) human insulin (insulin glulisine); Lys(B28), Pro(B29) human insulin (insulin lispro); Asp(B28) human insulin (insulin aspart); human insulin in which proline at position B28 is replaced by Asp, Lys, Leu, Val or Ala and in which Lys at position B29 can be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

[0167] Examples of insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin, Lys(B29)(N-tetradecanoyl)-des(B30) human insulin (insulin detemir, ); 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-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-γ-glutamyl)-des(B30) human insulin, B29-N-ω-carboxypentadecanoyl-γ-L-glutamyl-des(B30) human insulin (insulin degludec, ); 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.

[0168] Examples of GLP-1, GLP-1 analogs and GLP-1 receptor agonists are, for example, lixisenatide exenatide (exendin-4, a 39-amino acid peptide produced by the salivary glands of the Gila monster), liraglutide semaglutide, taspoglutide, albiglutide dulaglutide rExendin-4, CJC-1134-PC, PB-1023, TTP-054, Langlenatide / HM-11260C, CM-3, GLP-1 Eligen, ORMD-0901, NN-9924, NN-9926, NN-9927, Nodexen, Viador-GLP-1, CVX-096, ZYOG-1, ZYD-1, GSK-2374697, DA-3091, MAR-701, MAR709, ZP-2929, ZP-3022, TT-401, BHM-034, MOD-6030, CAM-2036, DA-15864, ARI-2651, ARI-2255, exenatide-XTEN, and glucagon-Xten.

[0169] Examples of oligonucleotides are, for example, mipomersen sodium It is a cholesterol-reducing antisense therapeutic agent for the treatment of familial hypercholesterolemia.

[0170] Examples of DPP4 inhibitors are vildagliptin, sitagliptin, denagliptin, saxagliptin, berberine.

[0171] Examples of hormones include pituitary hormones or hypothalamic hormones or regulatory active peptides and their antagonists, such as gonadotropins (follicle-stimulating hormone, luteinizing hormone, chorionic gonadotropin, gonadotropin), somatropine (growth hormone), desmopressin, terlipressin, gonadorelin, triptorelin, leuprorelin, buserelin, nafarelin, and goserelin.

[0172] Examples of polysaccharides include glucosaminoglycane, hyaluronic acid, heparin, low molecular weight heparin or ultra-low molecular weight heparin or derivatives thereof, or sulfated polysaccharides (e.g., the polysulfated forms of the above polysaccharides), and / or their pharmaceutically acceptable salts. An example of a pharmaceutically acceptable salt of polysulfated low molecular weight heparin is enoxaparin sodium. An example of a hyaluronic acid derivative is Hylan G-F 20 It is a sodium hyaluronate.

[0173] As used herein, the term "antibody" refers to an immunoglobulin molecule or an antigen-binding portion thereof. Examples of antigen-binding portions of immunoglobulin molecules include F(ab) and F(ab')2 fragments, which retain the ability to bind antigen. Antibodies can be polyclonal, monoclonal, recombinant, chimeric, deimmunized or humanized antibodies, fully human antibodies, non-human (e.g., murine) antibodies, or single-chain antibodies. In some embodiments, the antibody has effector functions and can fix complement. In some embodiments, the antibody has a reduced or no ability to bind Fc receptors. For example, the antibody can be an isotype or subtype, an antibody fragment, or a mutant that does not support binding to Fc receptors, e.g., it has a mutagenized or deleted Fc receptor-binding region. The term antibody also includes antigen-binding molecules based on tetravalent bispecific tandem immunoglobulins (TBTIs) and / or dual variable domain antibody-like binding proteins having a cross-over binding domain orientation (CODV).

[0174] The term "fragment" or "antibody fragment" refers to a polypeptide (e.g., an antibody heavy chain and / or light chain polypeptide) derived from an antibody polypeptide molecule that does not include the full-length antibody polypeptide but still includes at least a portion of the full-length antibody polypeptide capable of binding antigen. Antibody fragments can include a cleaved portion of the full-length antibody polypeptide, although the term is not limited to such cleaved fragments. Antibody fragments useful in the present disclosure include, for example, Fab fragments, F(ab')2 fragments, scFv (single-chain Fv) fragments, linear antibodies, monospecific or multispecific antibody fragments (such as bispecific, trispecific, tetraspecific, and multispecific antibodies (e.g., diabodies, triabodies, tetrabodies)), monovalent or multivalent antibody fragments (such as divalent, trivalent, tetravalent, and multivalent antibodies), minibodies, chelated recombinant antibodies, triabodies or diabodies, intracellular antibodies, nanobodies, small modular immunopharmaceuticals (SMIPs), binding domain immunoglobulin fusion proteins, camelized antibodies, and antibodies containing VHHs. Additional examples of antigen-binding antibody fragments are known in the art.

[0175] The term "complementary determining region" or "CDR" refers to short polypeptide sequences within the variable regions of both the heavy chain polypeptide and the light chain polypeptide that are primarily responsible for mediating specific antigen recognition. The term "framework region" refers to the amino acid sequences within the variable regions of both the heavy chain polypeptide and the light chain polypeptide that are not CDR sequences and are primarily responsible for maintaining the correct positioning of the CDR sequences to permit antigen binding. Although the framework region itself generally does not directly participate in antigen binding, as is known in the art, certain residues within the framework region of some antibodies can directly participate in antigen binding or can affect the ability of one or more amino acids in the CDR to interact with the antigen.

[0176] Examples of antibodies are anti-PCSK-9 mAb (e.g., Alirocumab), anti-IL-6 mAb (e.g., Sarilumab), and anti-IL-4 mAb (e.g., Dupilumab).

[0177] Pharmaceutically acceptable salts of any API described herein are also contemplated for use in the drug or agent in the drug delivery device. Pharmaceutically acceptable salts are, for example, acid addition salts and basic salts.

[0178] Those skilled in the art will understand that various components of the APIs, formulations, devices, methods, systems, and embodiments described herein can be modified (added and / or removed) without departing from the full scope and spirit of the present disclosure, and the present disclosure encompasses such modifications and any and all equivalents thereof.

[0179] Reference numerals

[0180] 10 Housing (outer shell)

[0181] 11a, 11b Windows

[0182] 12 Insert

[0183] 13 Side wall

[0184] 14 Tube

[0185] 15 Arm

[0186] 16 Bottom wall

[0187] 17 Thread

[0188] 18 Spline tooth

[0189] 19 Annular second part

[0190] 19a Spline tooth

[0191] 19b Arm (spline)

[0192] 19c Arm (snap clamp)

[0193] 19d Opening

[0194] 20 Reservoir unit body

[0195] 30 Piston rod

[0196] 40 Driving member

[0197] 40a First driving member

[0198] 40b Second driving member

[0199] 41 Spline teeth

[0200] 42 First locking feature

[0201] 42a First locking part

[0202] 42b Second locking part

[0203] 43 Second locking feature

[0204] 44 Lock

[0205] 45 Threaded guide

[0206] 50 Nut

[0207] 60 Dose setting member

[0208] 60a Lower part of dose setting member

[0209] 60b Upper part of dose setting member

[0210] 70 Button

[0211] 80 Dose selector

[0212] 90 Torsion spring

[0213] 91 Hook

[0214] 100 Reservoir

[0215] 110 Metering element

[0216] 120 Adapter plate

[0217] 130 Adapter spring

[0218] 140 Bearing

[0219] Axis I

[0220] D Delivery direction

Claims

1. An institutional unit for a drug delivery device, the institutional unit comprising: A housing (10), the housing having a proximal end and a distal end, A piston rod (30), the piston rod (30) being movable relative to the housing (10), A dose setting and driving mechanism, the dose setting and driving mechanism being configured to perform a dose setting operation for setting a dose to be delivered and a dose delivery operation for delivering the set dose by transmitting a delivery force to the piston rod (30), so as to drive the piston rod (30) in a distal direction relative to the housing (10) during the dose delivery operation, the dose setting and driving mechanism comprising A first driving member (40a), the first driving member being mechanically cooperative with the piston rod (30) to transmit the delivery force to the piston rod (30), the first driving member (40a) being axially fastened and rotatable relative to the housing (10), wherein rotation of the first driving member (40a) relative to the housing (10) in the delivery direction causes movement of the piston rod (30) in the distal direction, and rotation in a direction opposite to the delivery direction causes proximal movement of the piston rod (30), A second driving member (40b), the second driving member being arranged to be mechanically coupled to the first driving member (40a) to transmit the delivery force to the first driving member (40a), and An adapter mechanism, the adapter mechanism having at least two different states: a setting state and a delivery state, wherein, in the setting state, the second driving member (40b) is rotationally fastened relative to the housing (10) at least against rotation in the delivery direction, and wherein, in the delivery state, the second driving member (40b) is rotatable relative to the housing (10) in the delivery direction, wherein, in the setting state, the first driving member (40a) is rotatable relative to the second driving member (40b) and the housing (10) at least in the delivery direction, and wherein, in the delivery state, the second driving member (40b) is rotationally locked to the first driving member (40a) at least against rotation of the second driving member (40b) relative to the first driving member (40a) in the delivery direction.

2. The institutional unit for a drug delivery device according to claim 1, wherein the dose setting and driving mechanism comprises a dose setting member (60), the dose setting member being movable relative to the housing (10) from an initial position to a dose setting position in the setting state so as to set a dose of a drug.

3. The mechanism unit for a drug delivery device according to claim 1 or 2, wherein the mechanism unit is configured to be connected to a reservoir unit to assemble the two units for the drug delivery device, and wherein the first drive member (40a) is accessible from the outside of the housing (10) for manipulation such that in the set state, the position of the piston rod (30) relative to the housing (10) can be adjusted by rotation of the first drive member (40a) before or after connection of the mechanism unit and the reservoir unit.

4. The mechanism unit for a drug delivery device according to claim 1 or 2, wherein the second drive member (40b) is axially movable relative to the first drive member (40b) and the housing (10) for switching between the set state and the delivery state.

5. The mechanism unit for a drug delivery device according to claim 1 or 2, wherein the first drive member (40a) engages with the piston rod (30), and wherein the piston rod (30) engages with the housing (10).

6. The mechanism unit for a drug delivery device according to claim 5, wherein the first drive member (40a) is threadedly engaged with the piston rod (30), and the piston rod (30) is splined to the housing (10).

7. The mechanism unit for a drug delivery device according to claim 6, wherein the first drive member (40a) is rotatable relative to the piston rod (30).

8. The mechanism unit for a drug delivery device according to claim 5, wherein the first drive member (40a) is splined to the piston rod (30), and the piston rod (30) is threadedly engaged with the housing (10).

9. The mechanism unit for a drug delivery device according to claim 8, wherein the first drive member (40a) is rotatably fastened to the piston rod (30).

10. The mechanism unit for a drug delivery device according to claim 1 or 2, wherein the first drive member (40a) is fastened against proximal and distal movement relative to the housing (10).

11. The mechanism unit for a drug delivery device according to claim 1 or 2, wherein the first driving member (40a) includes a first locking feature (42), and the second driving member (40b) includes a second locking feature (43), and wherein, In the delivery state, the first locking feature (42) engages with the second locking feature (43).

12. The mechanism unit for a drug delivery device according to claim 11, wherein, In the set state, the first locking feature (42) and the second locking feature (43) are disengaged.

13. The mechanism unit for a drug delivery device according to claim 11, wherein, In the set state, the first locking feature (42) engages with the second locking feature (43).

14. The mechanism unit for a drug delivery device according to claim 11, wherein, The first locking feature (42) and the second locking feature (43) are configured such that when the first locking feature (42) engages with the second locking feature (43), the first locking feature (42) can rotate relative to the second locking feature (43) in the delivery direction and is rotationally fastened relative to the second locking feature (43) in the direction opposite to the delivery direction.

15. The mechanism unit for a drug delivery device according to claim 1 or 2, wherein the mechanism unit comprises an energy storage (90), wherein the energy storage is configured such that in a set state, energy is stored in the energy storage due to the movement of a setting member by a user, and wherein the energy storage is configured such that in a delivery state, the stored energy of the energy storage is released to support the delivery process.

16. The mechanism unit for a drug delivery device according to claim 15, wherein the energy storage (90) is a driving spring.

17. A drug delivery device comprising a reservoir unit and a mechanism unit according to any one of the preceding claims, the reservoir unit comprising or being provided for holding a reservoir (100) containing a drug.

18. The drug delivery device according to claim 17, wherein the reservoir (100) is a cartridge.

19. The drug delivery device according to claim 17 or 18, wherein the drug delivery device is an injection device.

20. A method of manufacturing a drug delivery device, the method comprising the following steps: a) providing a reservoir unit comprising a reservoir (100) containing a drug, wherein a stopper is movably held in the reservoir, and the reservoir is held in a reservoir unit body (20), b) providing a mechanism unit according to any one of claims 1 - 16, c) determining the stopper position of the stopper relative to the reservoir unit body (20), d) determining a desired piston rod position of the piston rod (30) relative to the housing (10) based on the determined stopper position, wherein the desired piston rod position is determined such that if the mechanism unit is connected to the reservoir unit, the piston rod (30) and the stopper are arranged at a predetermined distance relative to each other, and determining a specific displacement distance by which the piston rod (30) must be displaced in the distal direction relative to the housing (10) to be in the desired piston rod position, e) in the set state of the mechanism unit, rotating the first drive member (40a) relative to the second drive member (40b) to displace the piston rod (30) relative to the housing (10) by the specific displacement distance, and f) after step e), connecting the reservoir unit and the mechanism unit to each other for the drug delivery device.

Images