Double cartridge injection device

Abstract

Double Cartridge Injection Device The present disclosure relates to an injection device and to a respective drive mechanism for an injection device (1), wherein the injection device comprises a housing (8) to accommodate a first medicament container (10) and a second medicament container (110), wherein the first medicament container (10) and the second medicament container (110) each comprise a barrel (11; 111) sealed in a longitudinally proximal direction (3) by a first stopper (12) and by a second stopper (112), the drive mechanism (5) comprising: - a body (20), - a first piston rod (30) and a second piston rod (130), each of which are longitudinally displaceable relative to the body (20) to operably engage with the first stopper (12) and the second stopper (112), - a first driven member (40) and a second driven member (140) coaxial with and mechanically engaged with the first piston rod (30) and the second piston rod (140) respectively, to advance the first piston rod (30) and the second piston rod (130) in a longitudinally distal direction (2), and - a driver (50) rotatable relative to the body (20) and selectively engageable with the first driven member (40) and with the second driven member (140) to induce a sequential distally directed displacement of the first piston rod (30) and the second piston rod (130).

Description

[0001] PAT23286-WO-PCT

[0002] Double Cartridge Injection Device

[0003] Description

[0004] Field

[0005] The present disclosure relates to the field of injection devices, and in particular to injection devices configured to inject a first medicament and a second medicament separately, e.g., sequentially. In a further aspect the present disclosure relates to a drive mechanism for such an injection device.

[0006] Background

[0007] Drug delivery devices allowing for multiple discrete or continuous dosing of a required dosage of a liquid medicinal product and further providing administration of such liquid drug to a patient, are well known in the prior art. Generally, such devices serve substantially the same purpose as that of an ordinary syringe. Some medicaments require administration by way of infusion.

[0008] Drug delivery devices, such as pen-type injectors, must meet a number of user-specific requirements. For instance, with patients suffering from chronic diseases such as diabetes, the patient may be physically infirm and may also have impaired vision. Therefore, suitable drug delivery devices and especially those intended for home medication must be robust in construction and easy to use. Furthermore, manipulation and general handling of the device and its components should be intelligible and easily understandable. Such injection devices should provide setting and subsequent dispensing of a dose of a medicament of equal or variable size. Moreover, the dose setting as well as the dose dispensing procedure must be easy to operate and unambiguous.

[0009] Some drug delivery or injection devices provide selecting of a dose of a medicament of variable size and subsequent injecting of the dose previously set. Other injection devices provide setting and dispensing of a fixed dose. Here, the amount of medicament that should be injected in accordance with a given prescription schedule is always the same and does not change or cannot be changed over time.

[0010] Some injection devices are implemented as reusable injection devices offering a user to replacea medicament container, such as a cartridge. Other injection devices are implemented as a disposable injection device. With disposable injection devices it is intended to discard the entirety of the injection device when the content, i.e., the medicament, has been used up.

[0011] Disposable injection devices may be prefilled with the injectable medicament.

[0012] Medical devices, such as drug delivery devices or injection devices may have a limited lifetime. Due to regulatory provisions or for patient safety, medical devices or drug delivery devices may only be used for a limited number of times. Also, some medical devices, drug delivery devices or injection devices or parts thereof may be intended only for one-time use. They may be designed or constructed as disposable devices or device components, which are intended to be discarded after use.

[0013] In some cases co-administration of two separate substances or medicaments is required, wherein the medicaments is injected or administered sequentially i.e., one after the other. Here, it should be provided that a dose of the first substance is completely delivered or injected into the tissue of the patient before the delivery of the second substance or medicament is initiated.

[0014] It is of particular benefit to provide an injection device that provides both delivery or injection of a first medicament and of a second medicament truly sequentially. The injection device should comprise a rather compact design. It should be robust in handling and should provide a durable and reliable functionality. Moreover, the injection device should enable setting and dispensing of doses of first and second medicaments of different and / or of user-selectable quantity. In addition, the total number of components of the injection device should be reduced or should not exceed a predefined maximum component number to improve manufacturability, reliability and recyclability.

[0015] Furthermore, the injection device should provide an individually adjustable zero dose mechanism or priming gap elimination mechanism by way of which it can be guaranteed that upon deployment or initial use of the injection device there will be dispensed and injected a full dose of the medicament.

[0016] Summary

[0017] According to one aspect the present disclosure relates to a drive mechanism for an injection device, such as a pen-type injector. The injection device comprises a housing to accommodate a first medicament container and a second medicament container. The first medicament container comprises a first barrel sealed in a longitudinal proximal direction by a first stopper.The second medicament container comprises a second barrel, which is sealed in a longitudinal proximal direction by a second stopper. The injection device may be of elongated or tubular shape. Towards a distal direction the injection device comprises a distal end, which may be the injection end. In the opposite direction, hence the proximal direction, the injection device comprises a proximal end, which is furthest away from the injection end.

[0018] The proximal end of the injection device may be provided with at least one dose setting element or trigger to provide control of a dose setting operation and a dispensing operation.

[0019] The drive mechanism is or forms part of a functional unit of the injection device. In some examples the drive mechanism comprises or provides all the mechanically interacting components necessary to urge the first stopper and / or the second stopper towards the distal direction to thereby expel a well-defined amount of the medicament, i.e., a dose of the medicament, through a distal outlet of the respective medicament container.

[0020] The medicament containers may be implemented as prefilled syringes or as cartridges comprising a distal outlet, which is either readily equipped or provided with an injection needle or which can be coupled or connected with an injection needle to dispense and / or to inject the dose of the medicament through the injection needle into biological tissue.

[0021] The drive mechanism comprises a body. The body may be located inside a housing of the injection device. The body may form or constitute a mounting frame, to which some or all components of the drive mechanism can be attached and / or assembled to. The drive mechanism further comprises a first piston rod, which is longitudinally displaceable relative to the body to operably engage with the first stopper of the first medicament container. The drive mechanism further comprises a second piston rod, which is likewise longitudinally displaceable relative to the body to operably engage with the second stopper of the second medicament container.

[0022] Moreover, the drive mechanism comprises a first driven member, which is, e.g., coaxial with and rotatable relative to the first piston rod. The first driven member is mechanically engaged with the first piston rod and is rotatable relative to the body to advance the first piston rod in distal direction.

[0023] According to some examples, the first driven member is coaxial with the first piston rod and is mechanically engaged with the first piston rod.The drive mechanism further comprises a second driven member, which is, e.g. coaxial with and rotatable relative to the second piston rod. The second driven member is mechanically engaged with the second piston rod and is rotatable relative to the body to advance the second piston rod in distal direction.

[0024] According to some examples, the second driven member is coaxial with the second piston rod and is mechanically engaged with the second piston rod.

[0025] The first driven member and the second driven member may be in direct mechanical connection with the respective first or second piston rod. In this way, rotation of the first driven member may directly lead to a respective distally directed advancing motion of the first piston rod. Likewise, rotation of the second driven member relative to the body may induce a respective distally directed advancing motion of the second piston rod.

[0026] The first driven member and the second driven member may be mechanically decoupled from each other. This allows for a separate and independent advancing motion of the first piston rod and the second piston rod.

[0027] The drive mechanism further comprises a driver, e.g., a common driver, which is rotatable relative to the body. The driver is selectively engageable with the first driven member and with the second driven member to induce or to trigger or to control a sequential distally directed displacement of the first piston rod and the second piston rod, respectively.

[0028] In some examples the driver may be rotatable relative to the body, e.g., between a first angular position and a second angular position. It may be in mechanical engagement with the first driven member only. When reaching the second angular position relative to the body the driver may mechanically disengage from the first driven member and engage with the second driven member.

[0029] According to another example the driver may get in mechanical engagement with the second driven member only after having disengaged from the first driven member; and vice versa. Hence, the driver is mechanically engageable with the second driven member only when disengaged from the first driven member; and vice versa. Hence, the driver is mechanically engageable with the first driven member only when disengaged from the second driven member.

[0030] According to a further example the driver may be further rotated while in engagement with thesecond driven member and while it is decoupled or disconnected from the first driven member, until it reaches a third angular position in which the driver disconnects or decouples from the second driven member and re-engages the first driven member. Any rotation of the driver may then no longer cause any movement of the second driven member but produces rotation of the first driven member only.

[0031] Since the first and second driven members are mechanically engaged with the first and second piston rods respectively, and since there is no mechanical connection between the first driven member and the second piston rod or between the second driven member and the first piston rod by the selective and mutually excluding mechanical engagement of the driver to only one of the first driven member and the second driven member at a time, there can be provided a pure sequential displacement of the first and second piston rods relative to the body, which may then lead to the respective displacement of the first and second stoppers thereby expelling the first and second medicament sequentially, i.e., one after the other.

[0032] According to a further example the driver comprises a driver toothed section to mesh with at least one of a first driven toothed section of the first driven member and a second driven toothed section of the second driven member. The driver toothed section may comprise a number of gearwheel teeth. Likewise, the first and second driven toothed sections of first and second driven member comprise complementary shaped teeth of complementary shaped gears or drive wheels.

[0033] By way of the driver toothed section meshing with at least one or with only one of the first driven toothed section or the second driven toothed section there can be provided a pure sequential transfer of moment of force or of rotational motion, e.g. of a torque from the driver to the first driven member and thereafter to the second driven member.

[0034] According to a further example the driver toothed section is configured to mesh with the first driven toothed section of the first driven member and to mesh with the second driven toothed section of the second driven member sequentially and / or alternately. Here, and when the driver toothed section is mechanically engaged with the first driven toothed section it is mechanically disengaged from the second driven toothed section. Vice versa, when the driver toothed section is engaged with the second driven toothed section of the second driven member, the first driven toothed section of the first driven member is disengaged from the driver toothed section. This way, the driver is configured to transfer a driving force or driving momentum to the first driven member and to the second driven member alternately, i.e., sequentially as the driven member is subject to a continuous movement or rotation.Accordingly, and due to the configuration of the driver toothed section in combination with the first and second driven toothed sections of the first and second driven members, there can be provided a selective and sequential transfer of a driving force or driving torque from the driver to only one of the first driven member and the second driven member at a time.

[0035] The driver toothed section, the first driven toothed section and the second driven toothed section are shaped and configured to induce a motion or rotation to only one of the first and the second driven members when the driver toothed section and hence the driver is subject to a driving rotation or driving movement.

[0036] According to a further example the first driven member and the second driven member each comprise a driven member gearwheel. The driven member gearwheel may be rotatable with respect to an axis of rotation, which may coincide with a longitudinal or central axis of the first piston rod. In some examples the first driven member may be rotationally supported on an outside of the first piston rod.

[0037] The same may also apply to the second driven member and its interaction with the second piston rod. Likewise, the second driven member may be rotationally supported on the second piston rod.

[0038] According to some examples the first and the second medicament container are arranged next to each other, e.g., they may be separated in a radial direction. With respect to a longitudinal direction, along which the first and second barrel of the first and second medicament containers extend, the first and second medicament containers may be aligned. In some examples, the distally located outlet of the first and the second medicament containers may be located in one and the same transverse plane extending substantially perpendicular to the elongation of the first and second piston rods.

[0039] Typically, the first piston rod and the second piston rod extend parallel to each other. Depending on the longitudinal size of the first medicament container and the second medicament container the first and second piston rods may be initially located at the same or at different longitudinal positions. Typically, and when the drive mechanism or the injection device is ready for injecting a dose, e.g., an initial dose, the first piston rod is in longitudinal abutment with the first stopper and the second piston rod is in longitudinal abutment with the second stopper.

[0040] According to a further example of the drive mechanism the driver toothed section of the driver is an outer toothed section. It may be located on an outer periphery of the driver. Here, the drivermay be located radially between the first driven member and the second driven member. Also here, the driven member or driven member's gear wheel comprises an outside facing surface structure that is provided with the driven toothed section.

[0041] By placing or arranging the driver between the first driven member and the second driven member, e.g. radially therebetween, there can be provided a rather compact design of the drive mechanism and hence of the entire injection device. In this way the driver may be rather easily rotationally engaged with both driven members.

[0042] According to another example the driver comprises a driver ring, with the driver toothed section located on an inside of the driver ring, e.g. on an internal diameter of the driver ring. The first and the second driven members are located radially inside the driver ring. Here, the driver toothed section is an internal toothed section and faces radially inwards and towards the center of the driver ring. The driver ring is a hollow ring structure inside which the first driven member and the second driven member are located.

[0043] By way of the driver ring, the first and the second driven members can be easily selectively engaged with a driver toothed section when the driver ring is subject to a rotation about its own central axis.

[0044] According to a further example the driver toothed section comprises a first toothed segment comprising a first circumferential extent of less than or equal to 180°. With such a first toothed segment there can be provided a selective and alternating meshed engagement between the driver toothed section of the driver and a respective driven toothed section of the first driven member and the second driven member, respectively.

[0045] This applies equally to examples, wherein the driver and hence the driver toothed section is located radially between the first driven member and the second driven member and wherein the driver toothed section is located on an outside circumference of the driver, which may be then implemented as a conventional gearwheel. It may also apply to other examples, wherein the driver comprises a driver ring with an inner driver toothed section, which is located on the internal diameter of the driver ring.

[0046] By way of the limited circumferential extent of the first driver toothed section there can be provided an exclusive and alternating meshed engagement between the first and second driven members and the driver, respectively.With the driver toothed section comprising a circumferential extent of less than or equal to 180° it may be provided that the first driven member and the second driven member comprise driven toothed sections extending around the entire circumference of the respective first and second driven members, respectively.

[0047] According to a further example at least one of the first driven toothed section and the second driven toothed sections comprise a first toothed segment comprising a circumferential extent of less than or equal to 180°. Here, it may be at least one of the first and the second driven toothed sections that comprise a circumferential extent of less than 180° while the driver and hence the driver toothed section comprises a toothed segment extending around the entire outer or inner circumference of the driver.

[0048] According to a further example and when the driver toothed section comprises a first toothed segment comprising a first circumferential extent of less than or equal to 180° the driver toothed section may comprise a second toothed segment longitudinally adjacent to the first toothed segment and comprising a second circumferential extent that is smaller than the first circumferential extent of the first toothed segment.

[0049] Here, the second toothed segment may likewise mesh or engage with at least one or both of the driven toothed sections of the first and the second driven members respectively. But since the second circumferential extent of the second toothed segment of the driver toothed section has a reduced circumference, rotation of the driver can only be transferred to a reduced degree onto or into a respective rotation of the first and the second driven members respectively.

[0050] In this way a full revolution of the driver can produce a limited and reduced degree of rotation for at least one of the first driven member and the second driven member, which transfers or translates into a respectively reduced distally directed advancing motion of the first piston rod and the second piston rod, respectively.

[0051] Hence, by reducing the circumferential extent of a toothed segment of the driver toothed section there can be provided a reduction of the dose administered or injected by the drive mechanism when the driver rotates a single turn.

[0052] According to a further example the driver toothed section further comprises a third toothed segment longitudinally adjacent to the second toothed segment and comprising a third circumferential extent that is smaller than the second circumferential extent of the second toothed section. According to some examples the second toothed section is locatedlongitudinally between the first toothed segment and the third toothed segment. In this way and depending on the degree of axial or longitudinal relative displacement between the driver toothed section and the first and second driven toothed sections of first and second driven members there can be provided a stepwise increase or reduction of the size of a dose to be injected or expelled by the drive mechanism.

[0053] Typically, and during the process of dose injection the driver as well as the driven member are fixed with respect to the longitudinal position relative to each other and / or relative to the body. It may be only upon setting of a dose of different size, that at least one of the driver and the first and / or second driven members are subject to a longitudinal displacement relative to each other.

[0054] According to a further example of the drive mechanism the first piston rod longitudinally extends through the first driven member. Likewise, the second piston rod longitudinally extends or axially extends through the second driven member. Here, the first and second piston rod may serve as a bearing for the respective first and second driven members. Moreover, by way of the mutual mechanical engagement between the first driven member and the first piston rod and between the second driven member and the second piston rod a rotation of one of the first and the second driven members, e.g., as controlled or induced by the common driver, has a direct and distally advancing effect on the respective first or second piston rod, respectively.

[0055] According to a further example the first driven member is one of threadedly engaged with the first piston rod and rotationally fixed to the first piston rod while it is longitudinally displaceable relative to the first piston rod. In some examples the first driven member is threadedly engaged with the first piston rod and the first piston rod is longitudinally slidably engaged with the body.

[0056] Here, the body may comprise an insert with a through opening complementary shaped to the external cross-section of the first piston rod. The first piston rod may be rotationally secured or rotationally locked to the body. By way of the threaded engagement between the first piston rod and the first driven member and by a longitudinal fixing or constraint of the first driven member relative to the body, a rotation of the first driven member translates into a longitudinal displacement of the first piston rod relative to the body.

[0057] Here, an inside of the first driven member, hence an aperture of the first driven member through which the first piston rod extends, may be provided with an inner thread. The piston rod may be likewise provided with a complementary-shaped outer thread.

[0058] According to another example the first driven member is rotationally fixed to the first piston rod.Here, the first driven member may be likewise longitudinally fixed to the body or may be longitudinally constrained to the body. The first piston rod may be longitudinally displaceable relative to the first driven member. This may be achieved by a longitudinal groove extending along the external surface of the first piston rod and by a radially inwards extending projection of the first driven member, which is engaged with the groove; or vice versa.

[0059] In this way the piston rod is allowed to longitudinally displace relative to the driven member but remains rotationally locked to the driven member. Here, the longitudinal groove of the piston rod may intersect an outer thread of the threaded portion of the piston rod by way of which the piston rod is threadedly engaged with a complementary shaped aperture of the body or of an insert of the body of the drive mechanism. By way of the rotational interlock between the first driven member and the first piston rod a rotation or torque applied to the first driven member may be likewise and unalterably transferred into a respective rotation of the first piston rod, which due to its threaded engagement with the body experiences a longitudinal displacement relative to the body.

[0060] According to a further example the second driven member is threadedly engaged with the second piston rod and is rotationally fixed to the second piston rod thereby being longitudinally displaceable relative to the first piston rod. Generally, the second piston rod and the second driven member may be implemented in the same or identical manner as the first piston rod and the first driven member as described above; and vice versa.

[0061] According to another example the driver is longitudinally displaceable relative to the first driven member and relative to the second driven member for setting of a dose of variable size. Here and by longitudinally displacing the driver relative to the first and the second driven members different ones of the first and the second toothed segments of the driver toothed section may be brought into engagement or into a meshing engagement with a complementary shaped first or second toothed section of the first and the second driven members respectively.

[0062] By way of longitudinally displacing the driver relative to the first and second driven members and / or relative to the body a dose of variable size may be set. Here and since the circumferential extent of the first toothed segment and the second toothed segment of the driver defines a size of a dose to be injected, and when first and second driven members may be located on one and the same longitudinal position a respective longitudinal displacement of the driver leads to a simultaneous variation of doses to be expelled from the first and from second medicament containers respectively, in the course of a subsequent dose injection procedure as conducted by the drive mechanism.The longitudinal displacement of the driver may be user-induced or user-controlled. For providing a well-defined longitudinal displacement of the driver relative to the first and the second driven members and / or relative to the body of the drive mechanism there may be provided a dose setting element, which is mechanically engaged with the driver and which can be operated or e.g. rotated by a user to define at least one of a longitudinal displacement and a longitudinal positioning of the driver relative to at least one of the first and the second driven members and / or relative to the body of the drive mechanism.

[0063] According to a further example the drive mechanism comprises a dose setting element and a transfer member. The dose setting element is rotatable relative to the body and the transfer member is rotationally locked to the body. However, the transfer member is longitudinally fixed to the driver and is threadedly engaged with the dose setting element.

[0064] Typically, the transfer member is rotationally locked to the driver. It does not induce or influence a rotating motion of the driver. Rather, the transfer member is exclusively longitudinally fixed or longitudinally confined to the driver. By way of a threaded engagement between the transfer member and the dose setting element, a rotation of the dose setting element, e.g. relative to the body, may lead to a longitudinal displacement of the transfer member, which longitudinal displacement of the transfer member, e.g., relative to the body, causes a respective longitudinally directed translation or displacement of the driver.

[0065] Since the transfer member is hindered to rotate relative to the body the engagement with the dose setting element induces an exclusive longitudinal sliding motion of the transfer member relative to the body by way of which the driver can be longitudinally shifted between different longitudinal driver positions, which may coincide with different sizes of doses to be set by a user.

[0066] According to a further example the driver is mechanically coupled to a biasing member, e.g., to a biasing spring element. The biasing member, e.g., the spring element, is operable to exert a driving torque onto the driver for injecting of a dose. The biasing member may be pre-tensed or pre-biased. It may be provided and installed to the drive mechanism in a biased state, in which the biasing member stores a predefined amount of mechanical energy, which upon release leads to a driving of the driver in a driving direction for displacing the first and the second piston rod sequentially.

[0067] By way of the biasing member a force required for displacing the first and the second piston rod does not have to be provided or exerted by a user of the drive mechanism or injection device.Rather, the biasing member may be configured to provide the entirety of the dispensing force required for displacing the first and the second piston rod in the distal direction.

[0068] According to some examples the biasing member is or comprises a spirally or helically wound torsion spring, which can be biased by rotating its opposite ends relative to each other. Upon release of mechanical energy a portion of the mechanical energy stored in the biasing member can be used to exert a driving torque onto the driver under the action of which the driver starts to move in a driving direction. This biasing member-induced rotation of the driver then translates or transfers into a distally directed advancing motion or displacement of the first and the second piston rods respectively.

[0069] According to a further example the drive mechanism comprises an interlock with a locking member, which is mechanically engageable with the driver. The locking member is transferable between a locking state and a release state relative to the driver. When in the locking state the locking member prevents rotation of the driver. When in the release state the driver is free to rotate. In some examples the driver may comprise a ratchet structure on its external circumference that is in permanent or transient engagement with the locking member of the interlock.

[0070] For transferring the interlock from the locking state into the release state it may be required to induce a longitudinal displacement between the locking member and the ratchet structure of the driver. This may be provided by or in the course of injecting the medicament. A respective unlocking or release movement may be automatically induced by a user, e.g. aiming to exert a dispensing force onto a dedicated portion of the injection device.

[0071] In some examples the injection device comprises a housing and the drive mechanism as described above. Here, a distally directed displacement of the housing relative to the drive mechanism, hence relative to the body of the drive mechanism, may be sufficient to bring the locking member and the ratchet structure of the driver out of engagement thereby releasing the driver which may then start to rotate under the action of the relaxing biasing member.

[0072] A longitudinal displacement between the driver and the locking member may be conducted against the action of a trigger or trigger spring. When a user no longer applies a respective force between the housing and the drive mechanism or body, the trigger spring may serve to return the interlock and / or the locking member into the locking state.

[0073] According to a further example the body comprises a distal insert and a proximal insert, whichare mutually connectable and movable relative to each other in the longitudinal direction from a preassembly configuration to a final assembly configuration. When in the pre-assembly configuration at least one of the first driven member and the second driven member is rotatable independently of the other one of the first driven member and the second driven member and / or independently of the driver. In the pre-assembly configuration the drive mechanism as such can be installed and arranged inside a housing of the injection device, e.g., together with the first and the second medicament containers.

[0074] However, in the pre-assembly configuration the injection device and hence the drive mechanism is not yet ready to use. Rather in the pre-assembly configuration at least one of the first and the second drive members is rotatable. Accordingly, also at least one of the first and the second piston rod may be freely movable or displaceable in the longitudinal direction, e.g. in proximal direction, which movement may be accompanied by a respective rotation of the respective driven member.

[0075] In this way and as long as in the pre-assembly configuration there may be provided a length adjustment of at least one of the first and the second piston rod so as to make sure that both piston rods get in direct longitudinal abutment with the respective first and second stoppers of first and second medicament containers before conducting a first injection procedure.

[0076] Insofar, and as long as it is in the pre-assembly configuration the drive mechanism may be calibrated or adjusted, e.g. in order to provide a priming gap elimination between a distal end of first and second piston rods and the proximally facing pressure receiving surfaces of first and second piston or stoppers of the respective first and second medicament containers.

[0077] By transferring the drive mechanism into the final assembly configuration the first and second driven member may be locked relative to the body. In such a locking configuration the first and the second driven members may be only allowed to rotate in a single direction, which is associated with a distally directed displacement of the respective piston rod while a rotation in the opposite direction, which may be provided with a proximally directed displacement of the respective piston rod, is effectively prevented or blocked.

[0078] In another aspect the present disclosure further relates to an injection device for sequentially injecting a first medicament and a second medicament provided by a first medicament container and by a second medicament container respectively. The injection device comprises a housing to accommodate the first medicament container and the second medicament container. The injection device further comprises a drive mechanism as described above. Since the injectiondevice comprises a drive mechanism as described above, all features, effects and benefits as described above in connection with the drive mechanism equally apply to the injection device; and vice versa. The injection device may be implemented as one of a disposable and a reusable injection pen. Hence, in some examples the injection device may be readily equipped with first and second medicament containers provided with first and second medicaments.

[0079] In other examples the injection device may be suitable for a replaceable arrangement or replaceable receipt of first and second medicament containers, which upon use or after use could be replaced by new ones.

[0080] According to a further example the injection device comprises an outer casing to enclose and / or to cover at least a portion of the drive mechanism. The outer casing is movable in the longitudinal direction relative to the drive mechanism to trigger an injection. The outer casing may be displaceable relative to the drive mechanism against the action of a return spring or trigger spring. In this way and when a distally directed force effect is no longer applied to the outer casing the outer casing may return into an initial state relative to the drive mechanism thereby reestablishing or re-activating an interlock, e.g., between a locking member and the driver.

[0081] In a further example, the outer casing is movable relative to the drive mechanism in a first longitudinal direction to transfer the interlock from the locking state into the release state and / or wherein the outer casing is movable relative to the drive mechanism in a second longitudinal direction, e.g., opposite the first longitudinal direction to transfer the interlock from the release state into the locking state. In this way, and simply by urging the injection device against an external stop, such a skin portion of a patient, there may be induced the movement of the outer casing relative to the drive mechanism along at least one of the first and the second longitudinal directions.

[0082] According to a further example the injection device comprises the first medicament container containing the first medicament and further comprising the second medicament container containing the second medicament.

[0083] In one example the first medicament and the second medicament may be equal medicaments. They may distinguish by their medicament concentration. According to further examples the first medicament and the second medicament may comprise first and second pharmaceutically active substances, wherein the first pharmaceutically active substance of the first medicament distinguishes from the second pharmaceutically active substance of the second medicament.In some examples, the first medicament and the second medicament may be provided inside the first and the second medicament containers in liquid injectable form.

[0084] Generally, the scope of the present disclosure is defined by the content of the claims. The disclosure is not limited to specific embodiments or examples but comprises any combination of elements of different embodiments or examples. Insofar, the present disclosure covers any combination of claims and any technically feasible combination of the features disclosed in connection with different examples or embodiments.

[0085] The terms “drug” or “medicament” are used synonymously herein and describe a pharmaceutical formulation containing one or more active pharmaceutical ingredients or pharmaceutically acceptable salts or solvates thereof, and optionally a pharmaceutically acceptable carrier. An active pharmaceutical ingredient (“API”), in the broadest terms, is a chemical structure that has a biological effect on humans or animals. In pharmacology, a drug or medicament is used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being. A drug or medicament may be used for a limited duration, or on a regular basis for chronic disorders.

[0086] As described below, a drug or medicament can include at least one API, or combinations thereof, in various types of formulations, for the treatment of one or more diseases. Examples of API 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 or single stranded DNA (including naked and cDNA), RNA, antisense nucleic acids such as antisense DNA and RNA, small interfering RNA (siRNA), ribozymes, genes, and oligonucleotides. Nucleic acids may be incorporated into molecular delivery systems such as vectors, plasmids, or liposomes. Mixtures of one or more drugs are also contemplated.

[0087] The drug or medicament may be contained in a primary package or “drug container” adapted for use with a drug delivery device. The drug container may be, e.g., a cartridge, syringe, reservoir, or other solid or flexible vessel configured to provide a suitable chamber for storage (e.g., shorter long-term storage) of one or more drugs. For example, in some instances, the chamber may be designed to store a drug for at least one day (e.g., 1 to at least 30 days). In some instances, the chamber may be designed to store a drug for about 1 month to about 2 years. Storage may occur at room temperature (e.g., about 20°C), or refrigerated temperatures (e.g., from about -4°C to about 4°C). In some instances, the drug container may be or may include a dualchamber cartridge configured to store two or more components of the pharmaceuticalformulation to-be-administered (e.g., an API and a diluent, or two different drugs) separately, one in each chamber. In such instances, the two chambers of the dual-chamber cartridge may be configured to allow mixing between the two or more components prior to and / or during dispensing into the human or animal body. For example, the two chambers may be configured such that they are in fluid communication with each other (e.g., by way of a conduit between the two chambers) and allow mixing of the two components when desired by a user prior to dispensing. Alternatively or in addition, the two chambers may be configured to allow mixing as the components are being dispensed into the human or animal body.

[0088] The drugs or medicaments contained in the drug delivery devices as described herein can be used for the treatment and / or prophylaxis of many different types of medical disorders.

[0089] Examples of disorders include, e.g., diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism 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 as described in handbooks such as Rote Liste 2014, for example, without limitation, main groups 12 (antidiabetic drugs) or 86 (oncology drugs), and Merck Index, 15th edition.

[0090] Examples of APIs for the treatment and / or prophylaxis of type 1 or type 2 diabetes mellitus or complications associated with type 1 or type 2 diabetes mellitus include an insulin, e.g., human insulin, or a human insulin analogue or derivative, a glucagon-like peptide (GLP-1), GLP-1 analogues or GLP-1 receptor agonists, or an analogue or derivative thereof, a dipeptidyl peptidase-4 (DPP4) inhibitor, or a pharmaceutically acceptable salt or solvate thereof, or any mixture thereof. As used herein, the terms “analogue” and “derivative” refers to a polypeptide which has a molecular structure which formally can be derived from the structure of a naturally occurring peptide, for example that of human insulin, by deleting and / or exchanging at least one amino acid residue occurring in the naturally occurring peptide and / or by adding at least one amino acid residue. The added and / or exchanged amino acid residue can either be codable 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 which has a molecular structure which formally can be derived from the structure of a naturally occurring peptide, for example that of human insulin, in which one or more organic substituent (e.g. a fatty acid) is bound to one or more of the amino acids. Optionally, one or more amino acids occurring in the naturally occurring peptide may have been deleted and / or replaced by other amino acids, including non-codeable amino acids, or amino acids, including non-codeable, have been added to the naturally occurring peptide.Examples of insulin analogues 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, wherein proline in position B28 is replaced by Asp, Lys, Leu, Vai or Ala and wherein in position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

[0091] Examples of insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin, Lys(B29) (N- tetradecanoyl)-des(B30) human insulin (insulin detemir, Levemir®); 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-gamma-glutamyl)-des(B30) human insulin, B29-N-omega-carboxypentadecanoyl-gamma-L-glutamyl-des(B30) human insulin (insulin degludec, Tresiba®); B29-N-(N-lithocholyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(w-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(w-carboxyheptadecanoyl) human insulin.

[0092] Examples of GLP-1, GLP-1 analogues and GLP-1 receptor agonists are, for example, Lixisenatide (Lyxumia®), Exenatide (Exendin-4, Byetta®, Bydureon®, a 39 amino acid peptide which is produced by the salivary glands of the Gila monster), Liraglutide (Victoza®), Semaglutide, Taspoglutide, Albiglutide (Syncria®), Dulaglutide (Trulicity®), rExendin-4, CJC-1134-PC, PB-1023, TTP-054, Langlenatide / HM-11260C (Efpeglenatide), HM-15211, CM-3, GLP-1 Eligen, ORMD-0901, NN-9423, NN-9709, 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, ZP-DI-70, TT-401 (Pegapamodtide), BHM-034. MOD-6030, CAM-2036, DA-15864, ARI-2651, ARI-2255, Tirzepatide (LY3298176), Bamadutide (SAR425899), Exenatide-XTEN and Glucagon-Xten.

[0093] An example of an oligonucleotide is, for example: mipomersen sodium (Kynamro®), a cholesterol-reducing antisense therapeutic for the treatment of familial hypercholesterolemia or RG012 for the treatment of Alport syndrom. Examples of DPP4 inhibitors are Linagliptin, Vildagliptin, Sitagliptin, Denagliptin, Saxagliptin, Berberine.

[0094] Examples of hormones include hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, and Goserelin.Examples of polysaccharides include a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra-low molecular weight heparin or a derivative thereof, or a sulphated polysaccharide, e.g. a poly-sulphated form of the above-mentioned polysaccharides, and / or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium. An example of a hyaluronic acid derivative is Hylan G-F 20 (Synvisc®), a sodium hyaluronate.

[0095] The term “antibody”, as used herein, refers to an immunoglobulin molecule or an antigenbinding 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. The antibody can be polyclonal, monoclonal, recombinant, chimeric, de-immunized or humanized, fully human, non-human, (e.g., murine), or single chain antibody. In some embodiments, the antibody has effector function and can fix complement. In some embodiments, the antibody has reduced or no ability to bind an Fc receptor. For example, the antibody can be an isotype or subtype, an antibody fragment or mutant, which does not support binding to an Fc receptor, e.g., it has a mutagenized or deleted Fc receptor binding region. The term antibody also includes an antigen-binding molecule based on tetravalent bispecific tandem immunoglobulins (TBTI) and / or a dual variable region antibody-like binding protein having cross-over binding region orientation (CODV).

[0096] The terms “fragment” or “antibody fragment” refer to a polypeptide derived from an antibody polypeptide molecule (e.g., an antibody heavy and / or light chain polypeptide) that does not comprise a full-length antibody polypeptide, but that still comprises at least a portion of a full-length antibody polypeptide that is capable of binding to an antigen. Antibody fragments can comprise a cleaved portion of a full length antibody polypeptide, although the term is not limited to such cleaved fragments. Antibody fragments that are useful in the present invention 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 bivalent, trivalent, tetravalent and multivalent antibodies, minibodies, chelating recombinant antibodies, tribodies or bibodies, intrabodies, nanobodies, small modular immunopharmaceuticals (SMIP), binding-domain immunoglobulin fusion proteins, camelized antibodies, and VHH containing antibodies. Additional examples of antigen-binding antibody fragments are known in the art.

[0097] The terms “Complementarity-determining region” or “CDR” refer to short polypeptide sequences within the variable region of both heavy and light chain polypeptides that are primarilyresponsible for mediating specific antigen recognition. The term “framework region” refers to amino acid sequences within the variable region of both heavy and light chain polypeptides that are not CDR sequences, and are primarily responsible for maintaining correct positioning of the CDR sequences to permit antigen binding. Although the framework regions themselves typically do not directly participate in antigen binding, as is known in the art, certain residues within the framework regions of certain antibodies can directly participate in antigen binding or can affect the ability of one or more amino acids in CDRs to interact with antigen.

[0098] 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).

[0099] Pharmaceutically acceptable salts of any API described herein are also contemplated for use in a drug or medicament in a drug delivery device. Pharmaceutically acceptable salts are for example acid addition salts and basic salts.

[0100] Those of skill in the art will understand that modifications (additions and / or removals) of various components of the APIs, formulations, apparatuses, methods, systems and embodiments described herein may be made without departing from the full scope and spirit of the present invention, which encompass such modifications and any and all equivalents thereof.

[0101] An example drug delivery device may involve a needle-based injection system as described in Table 1 of section 5.2 of ISO 11608-1 :2014(E). As described in ISO 11608-1 :2014(E), needlebased injection systems may be broadly distinguished into multi-dose container systems and single-dose (with partial or full evacuation) container systems. The container may be a replaceable container or an integrated non-replaceable container.

[0102] As further described in ISO 11608-1 :2014(E), a multi-dose container system may involve a needle-based injection device with a replaceable container. In such a system, each container holds multiple doses, the size of which may be fixed or variable (pre-set by the user). Another multi-dose container system may involve a needle-based injection device with an integrated non-replaceable container. In such a system, each container holds multiple doses, the size of which may be fixed or variable (pre-set by the user).

[0103] As further described in ISO 11608-1 :2014(E), a single-dose container system may involve a needle-based injection device with a replaceable container. In one example for such a system, each container holds a single dose, whereby the entire deliverable volume is expelled (full evacuation). In a further example, each container holds a single dose, whereby a portion of the deliverable volume is expelled (partial evacuation). As also described in ISO 11608-1:2014(E), a single-dose container system may involve a needle-based injection device with an integratednon-replaceable container. In one example for such a system, each container holds a single dose, whereby the entire deliverable volume is expelled (full evacuation). In a further example, each container holds a single dose, whereby a portion of the deliverable volume is expelled (partial evacuation).

[0104] Brief description of the drawings

[0105] Further details and examples of a drive mechanism and of an injection device will become further apparent by the following detailed description by making reference to the drawings, in which:

[0106] Fig. 1 shows a side view of an example of the injection device,

[0107] Fig. 2 shows a longitudinal cross-section A-A of the injection device according to Fig. 1, Fig. 3 shows a further longitudinal cross-section C-C of the injection device,

[0108] Fig. 4 is a transverse cross-section through the injection device according to Figs. 1-3, Fig. 5 is an exploded side view of the components of the injection device,

[0109] Fig. 6 shows the configuration according to Fig. 5 in a perspective illustration,

[0110] Fig. 7 is a perspective illustration of the driver,

[0111] Fig. 8 is a further cross-sectional illustration through the injection device,

[0112] Fig. 9 is a longitudinal cross-section along E-E as indicated in Fig. 8,

[0113] Fig. 10 is a perspective illustration of a dose setting element,

[0114] Fig. 11 shows the outer casing 24 and the cartridge holder of the injection device in a mutual assembly configuration,

[0115] Fig. 12 is a cross-section of a perspective view along H-H as indicated in Fig. 11, Fig. 13 is a perspective schematic illustration of components of the drive mechanism before reaching the pre-assembly configuration,

[0116] Fig. 14 is a schematic illustration according to Fig. 13 with the components of the drive mechanism in the pre-assembly configuration and

[0117] Fig. 15 shows an example of the drive mechanism in or after reaching the final assembly configuration,

[0118] Fig. 16 shows an example of a driver in a pre-assembly configuration and

[0119] Fig. 17 shows the driver engaged with first and second driven members of first and second piston rods,

[0120] Fig. 18 is a perspective illustration of the driver according to Figs. 16 and 17,

[0121] Fig. 19 shows a further example of the drive mechanism in a pre-assembly configuration, Fig. 20 shows a mutual engagement between the driver and two driven members, and Fig. 21 is an isolated perspective illustration of an example of the driver.Detailed Description

[0122] The injection device 1 as shown in the figures comprises an elongated geometry. The injection device 1 comprises a housing 8. Towards a distal direction 2 the injection device 1 comprises a cartridge holder 21 configured to hold and / or to retain a first and a second medicament container 10, 110.

[0123] Towards a proximal direction 3 the injection device 1 terminates by a dose setting element 80. The housing 8 comprises a body 20 and a cartridge holder 21 as well as an outer casing 24. The cartridge holder 21 comprises a mount or a base to receive the first medicament container 10 and the second medicament container 110. The first and second medicament containers 10, 110 each comprise a barrel 11, 111 and a stopper 12, 112 sealing the barrel 11, 111 towards the proximal direction 3. Towards a distal end the medicament containers 10, 110 are sealed by a seal 15, 115, e.g. by a pierceable seal 15, 115.

[0124] The barrels 11, 111 may comprise a vitreous material or a plastic material, such as cyclic olefin copolymer (COC) or cyclic olefin polymer (COP). Towards the distal end the barrels 11, 111 comprise a radially narrowed neck portion 16, 116. In some examples the medicament containers 10, 110 are implemented as so-called cartridges. The distal end and hence the seals 15, 115 may be pierceable by an injection needle (not illustrated).

[0125] The medicament containers 10, 110 are secured by the cartridge holder 21. There may be further provided with a distal insert 22 and a proximal insert 23, which may be attached or fixed mutually. Moreover, and as becomes apparent from the illustration in Figs. 5 and 6 the distal insert 22 may be connected and fixed to a proximal end of the cartridge holder 21. Here, the cartridge holder 21 and the distal insert 22 may comprise complementary-shaped snap features by way of which a snap fit connection can be established between the distal insert 22 and the cartridge holder 21.

[0126] The distal insert 22 is provided with a first and with a second through opening which are shaped and sized to receive first and second piston rods 30, 130 there through. Insofar, the body 20 and hence the distal insert 22 provides a longitudinal guide for both piston rods 30, 130.

[0127] The proximal insert 23 may be likewise provided with first and second through openings to engage or to longitudinally guide the first and the second piston rods 30, 130 therethrough. The proximal insert 23 may be fastened to the distal insert 22. As it is immediately apparent from the sequence of Figs. 13-15 the proximal insert 23 may be provided with a fastening element 34,which may be implemented as a snap-fit fastener to engage with one of a first and the second counter fastener element 35, 36 as provided at or integrated into the distal insert 22.

[0128] Here, the fastening element 34 may comprise a snap-fit protrusion with a beveled edge sized and configured to engage or to snap into a recessed portion or into a through opening of the first or second counter fastener element 35, 36.

[0129] The distal insert 22 is provided with a distal flange portion 28 and the proximal insert 23 is provided with a proximal flange portion 29. In the final assembly configuration as illustrated in Fig. 15 the longitudinal distance between the flange portions 28, 29 exactly matches a respective longitudinal extent of first and second driven members 40, 140.

[0130] The driven members 40, 140 each comprise a geared wheel 41, 141, which are provided with a toothed section 42, 142 on their outer circumferences. At a distal end the driven members 40, 140 comprise a ratchet section 48, 148 featuring an asymmetric toothed profile to engage with a counter ratchet element 38 as e.g. provided on the proximal insert 23.

[0131] In the preassembly configuration as shown in Fig. 14 and even before reaching the preassembly configuration as illustrated in Fig. 13 the counter ratchet element 38 may be optionally in a rather loose or no engagement with the toothed section 42, 142 of at least one of the first and the second driven members 40, 140. It may be only upon reaching the final assembly configuration according to Fig. 15 that the counter ratchet element 38 engages one of the ratchet sections 48, 148. There may be provided two separate ratchet elements 38, one of which is configured to engage with the ratchet section 148 and the other one (not illustrated) configured to engage with the ratchet section 48.

[0132] In this way and since the ratchet sections 48, 148 comprise an asymmetric profile the mutual engagement between the ratchet section 48, 148 with the counter ratchet element 38 serves to block a rotation of the driven member 40, 140 in one direction and allows a rotation of the driven member 40, 140 in the opposite direction. The opposite direction is the driving direction by way of which a rotation of the driven members 40, 140 translates into a distally directed advancing motion of the respective piston rods 30, 130.

[0133] The driven members 40, 140 may be further equipped or provided with a gliding surface 49, 149, which when reaching the preassembly configuration as shown in Fig. 14 is in sliding or gliding engagement with the through openings as provided by the proximal flange portion 29 of the proximal insert 23.The driven members 40, 140 are rotatably supported on the outer surface of the piston rod 30, 130. Here and as shown in the illustrated example the piston rods 30, 130 comprise a threaded section 32, 132 complementary shaped to an inner threaded section of the respective driven members 40, 140. In this way and by rotating the driven members 40, 140 in the driving direction and since the driven member 40 is longitudinally constrained between the distal and / or proximal flange portions 28, 29 as shown in Fig. 15 the rotation of the driven members 40, 140 inevitably leads to a respective distally advancing sliding displacement of the piston rods 30, 130.

[0134] The first piston rod 30 comprises a first pressure piece 31 located at the distal end of the respective first piston rod 30. The pressure piece serves to radially distribute a pressure effect onto the first stopper 12. Likewise, the second piston rod 130 may be equally equipped with a second pressure piece 131. However, the second pressure piece 131 may be also preinstalled to the proximal end of the second stopper 112 as shown in Fig. 3.

[0135] In the various illustrated examples the second piston rod 130 comprises a distal section 133 and a proximal section 134, which may be displaceable longitudinally relative to each other by a length adapter 135. In this way, varying longitudinal positions of e.g. the second stopper 112 relative to the first stopper 12 can be effectively compensated. Hence, before or in the course of final assembly of the injection device the total length of the second piston rod 130 can be varied by moving the distal section 133 relative to the proximal section 134 in the longitudinal direction.

[0136] The length adjuster 135 provides and serves for a respective longitudinal displacement between the distal section 133 and the proximal section 134. Once a final assembly configuration and a correct length of the second piston 130 has been obtained the length adjuster 135 may serve to immobilize the distal section 133 and the proximal section 134 relative to each other.

[0137] For this, the length adjuster 135 may be implemented as a mechanical component or mechanism byway of which the distal section 133 and the proximal section 134 can be mutually immobilized. According to further examples it is conceivable that the length adjuster 135 provides an adhesive, which is released when reaching a final assembly configuration. The adhesive may be curable thus allowing to immobilize the distal section 133 relative to the proximal section 134. In still further examples the length adjuster 135 may comprise a weldable or meltable piece or part by way of which the distal section 133 and the proximal section 134 may be melted or welded together, e.g. by applying thermal energy into the interface between the distal section 133 and the proximal section 134.As further illustrated in Fig. 13 the proximal flange portion 29 may comprise a bearing 27 to engage with a stem 85 of the dose setting element 80 as provided at the proximal end of the injection device 1. Here, the stem 85 may protrude or project longitudinally from a radial center of the cup-shaped dose setting element. The stem 85 may be provided with a fastener 86 complementary shaped to a counter fastener as provided at or in the bearing 27 (not illustrated). In this way, the dose setting element 80, confining at least a proximal portion of the outer casing 24 may be axially or longitudinally constrained to the body 20.

[0138] From the numerous figures it is immediately apparent that the first piston rod 30 and the second piston 130 extend parallel to each other. The driven members 40, 140 are arranged coaxial on the respective piston rods 30, 130.

[0139] As is further apparent from the cross-sections in Figs. 2 and 3 the first and second driven members 40, 140 may be mechanically engageable with a driver 50. One example of the driver 50 is shown in Fig. 7, where the driver 50 comprises a gear wheel 51 in form of a driver ring 53. The driver 50 comprises a toothed section 52 on an internal circumferential wall of the gear wheel 51 and hence on the inside of driver ring 53.

[0140] The toothed section 52 is segmented in numerous toothed segments 54, 55, 56. At a longitudinal proximal end the driver 50 is further provided with a counter connector 57 for establishing a longitudinal connection with a transfer member 90 as shown in Fig. 9. On an outside surface the driver 50 comprises a ratchet structure 58 provided with numerous regularly arranged ratchet teeth 59 of asymmetric profile.

[0141] The driver 50 is longitudinally constrained or longitudinally fixed to the transfer member 90, which comprises an annularly shaped rim portion 91 and which is rotationally fixed in the outer casing 24. Insofar, the transfer member 90 is hindered to rotate relative to the outer casing 24 and hence relative to the body 20.

[0142] The dose setting element 80 comprises a button portion 81 forming a closed proximal end face 84. The button portion 81, which comprises a cup-shaped receptacle with a tubular sidewall 82, is rotationally supported on an outside surface of the outer casing 24 at a proximal end of the outer casing 24. On an inside of the sidewall 82 the dose setting element 80 comprises a radially inwardly extending projection 87 that is engaged with a helical structure, hence with a thread 94 on an external peripheral wall of the transfer member 90.

[0143] Since the transfer member 90 is rotationally constrained to the body 20 and / or to the outercasing 24 a rotation of the dose setting element 80 relative to the outer casing 24 and / or relative to the body 20 induces a longitudinal sliding but non-rotational movement of the driver 50 relative to the body 20. The axial or longitudinal engagement between the transfer member 90 is immediately apparent from the cross-section of Fig. 9. There, the longitudinally extending connector 92 of the transfer member 90 is engaged with the counter connector 57, e.g. implemented as a circumferential groove at or near the proximal end of the driver 50. In this way and by rotating the dose setting element the longitudinal position of the driver 50 relative to the body 20 and hence relative to the driven members 40, 140 can be modified.

[0144] As it is immediately apparent from the illustration of Fig. 7 and depending on which one of the numerous toothed segments 54, 55, 56 is aligned in the longitudinal direction with the toothed section 42 of the first and second driven members 40, 140 a full or partial revolution of the driver 50 in the course of dispensing or injecting of a dose can be fully or only partially transferred into a rotation of the respective driven members 40, 140.

[0145] Moreover, since the first toothed segment 54 of the toothed section 51 of the driver 50, which comprises the largest circumferential extent of all of the toothed segments 54, 55, 56, has a circumferential extent of less than or equal to 180° it is ensured that only one of the first and second driven members 40, 140 is rotated at a time.

[0146] In this way a consecutive and sequential activation and movement of the first driven member 40 and the second driven member 140 can be provided. Accordingly, there will be provided a respective sequential and temporally non-overlapping longitudinal displacement of the first piston rod 30 and the second piston rod 130 when the driver 50 is rotated in the driving direction.

[0147] The size of a dose can be visually indicated to a user because the sidewall 82 of the dose setting element 80 comprises a transparent or partially transparent window 83 or a respective through recess through which a number of a scale 26 as provided on an outer circumferential surface 25 of the outer casing 24 is visible to a user.

[0148] Moreover, and as becomes apparent from the cross-section of Fig. 12 the drive mechanism 5 is further equipped with an interlock 70 comprising a locking member 71. The interlock 70 and the locking member 71 are integrated into the outer casing 24. In a locking configuration as illustrated in Fig. 12 a radially inwardly extending locking tooth of a flexibly and radially deformable locking member 71 protrudes radially inwardly from the sidewall 25 of the outer casing 24 and is in a locking engagement with the ratchet structure 58 as provided on theoutside surface of the driver 50.

[0149] Here, the shape and configuration of the ratchet structure 58 and the locking 72 tooth is such that a rotation of the driver 50 in the driving direction is effectively blocked. The locking configuration can be transferred into a release configuration or release state by longitudinally displacing the interlock 70 and hence the locking member 71 relative to the driver 50. This may be provided by displacing the entire outer casing 24 relative to the cartridge holder 21 or body 20 in the course of injecting of a dose of the medicament, e.g., when applying a distally directed pressure or force effect onto the outer casing 24 under the effect of which the outer casing 24 is moved in the distal direction 2 relative to the cartridge holder 21, which may be in direct abutment with the skin of a patient.

[0150] In this way, the locking member 71 may disengage from the ratchet structure 58 thereby allowing and enabling a free rotation of the driver 50, which may then start to rotate in a driving direction under the effect of a relaxing biasing member 60. The biasing member 60 may be pretensed or pre-biased and may provide a torque or torque effect onto the driver 50 for driving or rotating the driver in a driving direction, which is effective to displace the first and the second piston rods 30, 130, which serves to sequentially rotate the first and the second driven members 40, 140 and hence the respective piston rods 30, 130 engaged with the first and the second driven members 40, 140, respectively.

[0151] The outer casing 24 may be longitudinally slidably displaceable relative to the cartridge holder 21 against the action of a return element, e.g. a trigger spring (not illustrated). In this way and since the distal end of the cartridge holder 21 protrudes distally from the outer casing 24 the distal end of the cartridge holder 21, e.g., equipped with an injection needle (not illustrated), may be placed against the skin of a patient. To initiate or to trigger a dose dispensing operation the user may then urge the outer casing 24 in the distal direction 2 thereby longitudinally displacing the locking member 71 relative to the ratchet structure 58 and the ratchet teeth 59 by way of which the locking member 71 slides out of engagement from the ratchet structure 58. This disengagement then provides a free rotation of the driver 50 under the effect of a relaxing biasing member 60 or spring element.

[0152] The respective rotation of the driver 50 then sequentially translates into a respective rotation of the driven members 40, 140. Depending on the longitudinal position of the driver 50 relative to the driven members 40, 140, the latter of which being axially or longitudinally constrained to the body 21 , only one of the toothed segments 54, 55, 56 will be able to mesh with the complementary shaped toothed section 42, 142 of the respective driven members 40, 140 andthe respective gear wheels 41 , 141 at a time.

[0153] Since the two segments 54, 55, 56 distinguish with regards to their circumferential extent only a portion of a respective rotation of the driver 50 will be transferred to the respective driven member 40, 140 in the course of a continuous rotation of the driver 50 about its central axis.

[0154] Moreover, even the largest toothed segment 55 comprises a circumferential extent of less than or equal 180°. In this way it can be guaranteed and provided that only one of the driven members 40, 140 is rotated at a time while the driver 50 constantly rotates during and / or for injecting of a dose of the medicament.

[0155] As explained above, a rotation of the driven member 40 leads to a respective longitudinally and distally directed displacement of the piston rod 30 and to the injection of a medicament located in the first medicament container 10. A subsequent and sequential rotation of the driven member 140 leads to a respective longitudinally and distally directed displacement of the second piston rod 130 and to the injection of another medicament contained in the second medicament container 110.

[0156] In order to vary the size of a dose to be sequentially injected with the injection device 1 the user may rotate the dose setting element 80. A radially inwardly extending projection 87 provided on an inner circumferential surface 82 of the dose setting element 80 is in engagement with the threaded section 94 as provided on the outer circumferential surface of a sidewall or a rim portion 91 of the transfer member 90. The transfer member 90 is rotationally constrained and hence rotationally fixed to the outer casing 24 via the longitudinally extending guiding elements 93 and therefore hindered to rotate. Accordingly, and in response to a rotation of the dose setting element 80 the transfer member 90 is subject to a longitudinally, hence a distally or proximally directed sliding displacement relative to the body 20 and / or relative to the outer casing 24.

[0157] The longitudinal displacement of the transfer member 90 is unalterably translated to a respective longitudinal sliding displacement of the driver 50 through the engagement of the connector 92 protruding distally from the rim portion 91 of the transfer member 90 and the counter connector 57 as provided at or near the proximal end of the driver. Here, the counter connector 57 may comprise an annular groove, which is in snap fit engagement with the connector 92 of the transfer member 90. In this way, the driver 50 is free to rotate relative to the transfer member 90 but is and remains longitudinally restrained or longitudinally fixed to the transfer member 90.Accordingly, and in response to a rotation of the dose setting element 80 in one of a dose incrementing direction or dose decrementing direction the driver 50 is subject to a respective distally or proximally directed longitudinal displacement relative to the body 20 and hence relative to the driven members 40, 140. As a consequence of the longitudinal displacement of the driver 50 relative to the driven members 40, 140, the alignment of the toothed sections 42, 142 with one of the toothed segments 54, 55, 56 changes to another one of the toothed segments 54, 55, 56.

[0158] In this way, the degree of rotation or a rate of the rotation of the driven members 40, 140 changes with respect to the full rotation of the driver 50. Accordingly, the longitudinal displacement of the respective piston rods 30, 130 as defined by the degree of rotation of the individual driven members 40, 140, which are rotated by the driver 50 is subject to a respective change, being either increased or decreased. In this way, the size of the dose to be injected sequentially from the first medicament container 10 and the second medicament container 110 can be modified accordingly.

[0159] Figs. 16-18 illustrate another embodiment of the drive mechanism 5. Here, the first driven member 40 and the second driven member 140 remain substantially unmodified compared to the example shown in the Figs. 1-15. However, in this example or embodiment the driver 50 is provided as a gear wheel 51 with a toothed section 52 on the outer circumference of the gear wheel 51. Rather, the driver 50 comprises a hollow shaft or bearing by way of which it can be mounted or fixed on a bearing 95 of the transfer member 90. The shaft 95 may be rotatably locked to one end of the biasing member 60. It may be subject to a driving rotation upon release of the interlock 70, which may be implemented in a manner similar or different than as described above.

[0160] As is immediately apparent from the illustration of Fig. 16-18, the outer circumferential surface of the driver 50 is provided with numerous toothed segments 54, 55, 56 which are located longitudinally adjacent and which distinguish by their circumferential extent. The largest toothed segment 54 comprises a circumferential extent that is less than or equal to 180°. In this way and when in a final assembly configuration as shown in Fig. 17 only one of the toothed segments 54, 55, 56 is in longitudinal overlapping alignment with only one the toothed sections 42, 142 of the respective driven members 40, 140 at a time.

[0161] During a process of dose injection and when the driver 50 is subject to a rotation around the longitudinal axis of the bearing 95 only one of the toothed sections 42, 142 of respective driven members 40, 140 meshes with the respective toothed segment 54, 55, 56. During a fullrevolution or rotation of the driver 50 the driven members 40, 140 will be rotated to a reduced degree which is defined by the circumferential extent of that particular toothed segment 54, 55, 56 that gets in meshing engagement with the toothed sections 42, 142.

[0162] With the example according to Fig. 16-18 the driver 50 is located radially between the first and the second driven members 40, 140. In this way, there can be provided a rather compact design of the drive mechanism 5 and hence of the entire injection device 1.

[0163] In a further example according to Figs. 19-21 the driver 50 comprises a rather continuous toothed section 52 on an outside surface of a respective gear wheel 51. Here, toothed segments 44, 45, 46 of variable circumferential extent are provided on the outside surface of the driven members 40, 140. Here, the same principle as described above can be implemented.

[0164] The circumferential extent of the largest toothed segment 44 may be less than or equal to 180°. in this way, there can be provided a likewise sequential transfer of angular momentum from the driver 50 to the driven members 40, 140.

[0165] Also here, and depending on the degree of longitudinal overlap between the toothed section 42 with its toothed segments 44, 45, 46 with the toothed section 52 of the driver 50 the degree of rotation of the driven members 40, 140 with a full revolution or rotation of the driver 50 can be varied. In this way, a size of a dose can be modified and set.Reference Numbers

[0166] 1 injection device

[0167] 2 distal direction

[0168] 3 proximal direction

[0169] 5 drive mechanism

[0170] 8 housing

[0171] 10 medicament container 11 barrel

[0172] 12 stopper

[0173] 14 sidewall

[0174] 15 seal

[0175] 16 neck portion

[0176] 20 body

[0177] 21 cartridge holder

[0178] 22 distal insert

[0179] 23 proximal insert

[0180] 24 outer casing

[0181] 25 sidewall

[0182] 26 scale

[0183] 27 bearing

[0184] 28 flange portion

[0185] 29 flange portion

[0186] 30 piston rod

[0187] 31 pressure piece

[0188] 32 threaded section

[0189] 34 fastening element

[0190] 35 counter fastener element 36 counter fastener element 38 counter ratchet element 40 driven member

[0191] 41 gear wheel

[0192] 42 toothed section

[0193] 44 toothed segment

[0194] 45 toothed segment

[0195] 46 toothed segment

[0196] 48 ratchet section49 gliding surface

[0197] 50 driver

[0198] 51 gearwheel

[0199] 52 toothed section

[0200] 53 driver ring

[0201] 54 toothed segment

[0202] 55 toothed segment

[0203] 56 toothed segment

[0204] 57 counter connector 58 ratchet structure

[0205] 59 ratchet teeth

[0206] 60 biasing member

[0207] 70 interlock

[0208] 71 locking member

[0209] 72 locking tooth

[0210] 80 dose setting element 81 button portion

[0211] 82 sidewall

[0212] 83 window

[0213] 84 proximal end face 85 stem

[0214] 86 fastener

[0215] 87 projection

[0216] 90 transfer member

[0217] 91 rim portion

[0218] 92 connector

[0219] 93 guiding element

[0220] 94 threaded section

[0221] 95 bearing

[0222] 110 medicament container 111 barrel

[0223] 112 stopper

[0224] 114 sidewall

[0225] 115 seal

[0226] 116 neck portion

[0227] 130 piston rod

[0228] 131 pressure piece132 threaded section 133 distal part

[0229] 134 proximal part 135 length adjuster 140 driven member 141 gearwheel 142 toothed section 148 ratchet section 149 gliding surface

Claims

33PAT23286-WO-PCTClaims1. A drive mechanism (5) for an injection device (1), wherein the injection device comprises a housing (8) to accommodate a first medicament container (10) and a second medicament container (110), wherein the first medicament container (10) comprises a first barrel (11) sealed in a longitudinal proximal direction (3) by a first stopper (12), and wherein the second medicament container (110) comprises a second barrel (111) sealed in the longitudinal proximal direction (3) by a second stopper (112), the drive mechanism (5) comprising:a body (20),a first piston rod (30) longitudinally displaceable relative to the body (20) to operably engage with the first stopper (12),a second piston rod (130) longitudinally displaceable relative to the body (20) to operably engage with the second stopper (112),a first driven member (40) mechanically engaged with the fist piston rod (30) and rotatable relative to the body (20) to advance the first piston rod (30) in distal direction (2), a second driven member (140) mechanically engaged with the second piston rod (130) and rotatable relative to the body (20) to advance the second piston rod (130) in distal direction (2),a driver (50) rotatable relative to the body (20) and selectively engageable with the first driven member (40) and with the second driven member (140) to induce a sequential distally directed displacement of the first piston rod (30) and the second piston rod (130).

2. The drive mechanism (5) according to claim 1, wherein the driver (50) comprises a driver toothed section (52) to mesh with at least one of a first driven toothed section (42) of the first driven member (40) and a second driven toothed section (142) of the second driven member (140) at a time.

3. The drive mechanism (5) according to claim 2, wherein the driver toothed section (52) is configured to mesh with the first driven toothed section (42) of the first driven member (40) and to mesh with the second driven toothed section (142) of the second driven member (140) sequentially and / or alternatively.

4. The drive mechanism (5) according to any one of the preceding claims, wherein the driver (50) is mechanically engageable with the second driven member (140) only when the driver (50) is disengaged from the first driven member (40); and vice versa.

345. The drive mechanism (5) according to any one of the preceding claims, wherein the first driven member (40) is coaxial with the first piston rod (30) and is mechanically engaged with the first piston rod (30).

6. The drive mechanism (5) according to any one of the preceding claims, wherein the second driven member (140) is coaxial with the second piston rod (130) and is mechanically engaged with the second piston rod (130).

7. The drive mechanism (5) according to any one of the preceding claims, wherein the first driven member (40) and the second driven member (140) each comprise a driven member gear wheel (42, 142).

8. The drive mechanism (5) according to any one of the preceding claims 2 - 7, wherein the driver toothed section (52) is an outer toothed section and wherein the driver (50) is located radially between the first driven member (40) and the second driven member (140).

9. The drive mechanism (5) according to any one of the preceding claims 2 - 7, wherein the driver (50) comprises a driver ring (53) with the driver toothed section (52) located on an inside of the driver ring (53), wherein the first and the second driven member's (40, 140) are located radially inside the driver ring (53).

10. The drive mechanism (5) according to any one of the preceding claims 2 - 9, wherein the driver toothed section (52) comprises a first toothed segment (54) comprising a first circumferential extent of less than or equal to 180°.

11. The drive mechanism (5) according to claim 10, wherein the driver toothed section (52) comprises a second toothed segment (55) longitudinally adjacent to the first toothed segment (54) and comprising a second circumferential extent that is smaller than the first circumferential extent of the first toothed segment (54).

12. The drive mechanism (5) according to any one of the preceding claims, wherein the driver (50) is longitudinally displaceable relative to the first driven member (40) and the second driven member (140) for setting of a dose of variable size.

13. The drive mechanism (5) according to any one of the preceding claims, further comprising a dose setting element (80) and a transfer member (90),wherein the dose setting element (80) is rotatable relative to the body (20),wherein the transfer member (90) is rotationally locked to the body (20), longitudinally fixed to the driver (50) and threadedly engaged with the dose setting element (80).

14. The drive mechanism (5) according to any one of the preceding claims, wherein the driver (50) is mechanically coupled to a biasing member (60), which is operable to exert a driving torque onto the driver (50) for injecting of a dose.

15. The drive mechanism (5) according to any one of the preceding claims, further comprising an interlock (70) with a locking member (71) mechanically engageable with the driver (50), wherein the locking member (71) is transferable between a locking state and a release state relative to the driver (50), wherein when in the locking state the locking member (71) prevents a rotation of the driver (50) and wherein when in the release state the driver (50) is free to rotate.

16. The drive mechanism (5) according to any one of the preceding claims, wherein the body (20) comprises a distal insert (22) and a proximal insert (23) mutually connectable and movable relative to each other in the longitudinal direction from a pre-assembly configuration to a final assembly configuration, wherein when in the pre-assembly configuration at least one of the first driven member (40) and the second driven member (140) is rotatable independently of the other one of the first driven member (40) and the second driven member (140) and / or independently of the driver (50).

17. An injection device (1) for sequentially injecting a first medicament and a second medicament provided by a first medicament container (10) and by a second medicament container (110), respectively, the injection device (1) comprising:a housing (8) to accommodate the first medicament container (10) and the second medicament container (110), anda drive mechanism (5) according to any one of the preceding claims connectable to the housing (8).

18. The injection device (1) according to claim 17, further comprising an outer casing (24) to enclose and / or to cover at least a portion of the drive mechanism (5), wherein the outer casing (24) is movable in the longitudinal direction relative to the drive mechanism (5) to trigger an injection.

19. The injection device (1) according to claim 17 or 18, further comprising the first medicament container (10) containing the first medicament and comprising the second medicament container containing the second medicament.

Images