Medicament deivery system, cartridge and reusable injector device

Abstract

A medicament delivery system (10) comprising a reusable injector device (100) and a cartridge (200) for use with the reusable injector device, the cartridge and the reusable injector device being combinable for medicament delivery and separable thereafter, wherein the cartridge comprises: a cassette outer housing (210); a pre-filled syringe (230) arranged within cassette outer housing, the pre-filled syringe comprising a needle (233); and a needle cover (240) arranged within the cassette outer housing and surrounding the pre-filled syringe, wherein, the reusable injector device comprises: a housing (110); a needle cover shuttle (120) displaceable within the housing against a needle cover shuttle spring (121); and a plunger rod (170) configured to dispense medicament from the pre-filed syringe in use; and wherein, when the cartridge and the reusable injector device are coupled, the needle cover shuttle engages the needle cover to bias the needle cover in a proximal direction.

Description

[0001] MEDICAMENT DEIVERY SYSTEM, CARTRIDGE AND REUSABLE INJECTOR DEVICE

[0002] FIELD OF INVENTION

[0003] The present invention relates to a medicament delivery system comprising a cartridge and a reusable injector device.

[0004] BACKGROUND

[0005] Medicament delivery devices, such as auto-injectors, are known in the art for dispensing a medicament to an injection site of a patient. Such medicament delivery devices typically comprise a needle in fluid communication with a syringe and a piston rod that is moveable to dispense a medicament within the syringe through the needle into the injection site.

[0006] In such medicament delivery devices, the piston rod may be actuated to dispense the medicament. Once the medicament has been dispensed, the needle may be covered by a needle shield and / or a needle cover and the medicament delivery device may be disposed of.

[0007] SUMMARY

[0008] In a first aspect of the invention, there is provided a medicament delivery system comprising a reusable injector device and a cartridge for use with the reusable injector device, the cartridge and the reusable injector device being combinable for medicament delivery and separable thereafter, wherein the cartridge comprises: a cassette outer housing; a pre-filled syringe arranged within cassette outer housing, the pre-filled syringe comprising a needle; and a needle cover arranged within the cassette outer housing and surrounding the pre-filled syringe, wherein the reusable injector device comprises: a housing; a needle cover shuttle displaceable within the housing against a needle cover shuttle spring; and a plunger rod configured to dispense medicament from the pre-filed syringe in use; and wherein, when the cartridge and the reusable injector device are coupled, the needle cover shuttle engages the needle cover to bias the needle cover in a proximal direction. Therefore, a medicament delivery system is provided in which components of the system are reusable, reducing waste. Furthermore, the invention improves safety by ensuring that the needle cover is automatically biased by the needle cover shuttle spring to cover the needle, wherein this biasing is simply and intuitively initiated by a user coupling the cartridge to the reusable injector device.

[0009] The medicament delivery system may be configured such that, when the cartridge and the reusable injector device are coupled, the needle cover is configured to be translated distally within the cassette outer housing from a primed position, in which the needle is surrounded by the needle cover, to a dose delivery position, in which at least a proximal end of the needle extends proximally outside of the needle cover for injection into an injection site.

[0010] Therefore, an intuitive mechanism for exposing a needle during an injection process is provided.

[0011] The medicament delivery system may be configured such that, when the cartridge and the reusable injector device are coupled, the needle cover is configured to be translated proximally within the cassette outer housing from the dose delivery position to a post-dose delivery position, in which the needle does not extend proximally outside of the needle cover.

[0012] Therefore, the needle is re-covered after dose delivery and safety of the system is improved.

[0013] The medicament delivery system may be configured such that, when the cartridge and the reusable injector device are coupled, the needle cover is biased to translate proximally within the cassette outer housing from the dose delivery position to the post-dose delivery position by the needle cover shuttle.

[0014] In this way, covering of the needle may be automatic in response to a user removing the medicament delivery system from an injection site, increasing safety of the system. The medicament delivery system may be configured such that, after the needle cover has moved from the dose delivery position to the post-dose delivery position, distal movement of the needle cover is inhibited by a needle cover return lock of the cartridge.

[0015] In this way, a user may be further prevented from accidentally contacting the needle, and so safety of the system may be increased.

[0016] The needle cover return lock may comprise a needle cover locking arm extending from the needle cover and a locking recess arranged in the cassette outer housing, the needle cover locking arm configured to become engaged with the locking recess to inhibit distal movement of the needle cover.

[0017] Therefore, a simple mechanism for improving safety of the system is provided.

[0018] The needle cover may be configured to be rotated within the cassette outer housing from an initial position to the primed position, wherein distal translation of the needle cover within the cassette outer housing is inhibited when the needle cover is in the initial position.

[0019] By inhibiting distal translation of the needle cover until the needle cover has first been rotated by a user, accidental exposure of the needle may be prevented and therefore safety of the system may be increased.

[0020] The cartridge may further comprise a cap coupled to the cassette outer housing, wherein rotation of the needle cover from the initial position to the primed position is responsive to removal of the cap from the cassette outer housing.

[0021] Therefore, an intuitive mechanism for rotating the needle cover is provided, with the needle cover being rotated as the cap is removed.

[0022] The medicament delivery system may be configured such that the cap cannot be removed from the cassette outer housing without rotating the needle cover.

[0023] Therefore, an intuitive mechanism for rotating the needle cover is provided. The cap may comprise a guide pin configured to be received in a track formed in the cassette outer housing, the guide pin configured to traverse the track during removal of the cap.

[0024] Therefore, a simple mechanism for controlling removal of the cap is provided.

[0025] Rotation of the needle cover from the initial position to the primed position may be inhibited until the cartridge is coupled to the reusable injector device.

[0026] Therefore, safety of the cartridge is increased, since a user will be inhibited from removing the cap and rotating the needle cover until the cartridge has been coupled to the reusable injector device, thereby preventing accidental needle exposure.

[0027] Rotation of the needle cover from the initial position to the primed position may be inhibited by a needle cover locking mechanism of the cartridge, and the needle cover locking mechanism may be configured to be engaged by an unlocking element of the reusable injector device when the cartridge is coupled to the reusable injector device, to unlock the needle cover for rotation.

[0028] Therefore, a simple mechanism for controlling rotation of the needle cover based on coupling of the cartridge to the reusable injector device is provided.

[0029] The needle cover locking mechanism may comprise a clip configured to releasably engage with the needle cover to inhibit rotation of the needle cover.

[0030] Therefore, a simple mechanism for controlling rotation of the needle cover based on coupling of the cartridge to the reusable injector device is provided.

[0031] The clip may be configured to be lifted out of a first cutout in the needle cover by the unlocking element, such that the needle cover is free to rotate from its initial position to its primed position.

[0032] Once the cartridge has been coupled to the reusable injector device and the needle sleeve has been rotated from its initial position to its primed position, return rotation back in the opposite direction from the primed position to the initial position may be inhibited. The reusable injector device may comprise at least one interlock arm displaceable to engage a respective recess in the cassette outer housing to couple the cartridge to the reusable injector device.

[0033] Therefore, a simple mechanism for coupling the cartridge to the reusable injector device is provided, improving safety.

[0034] The at least one interlock arm may be arranged to be displaced towards the respective recess responsive to displacement of the plunger rod during delivery of medicament.

[0035] Therefore, a simple mechanism for ensuring coupling of the cartridge to the reusable injector device during delivery of medicament is provided, improving safety.

[0036] Uncoupling of the cartridge from the reusable injector device may be inhibited during delivery of medicament.

[0037] In this way, safety of the system may be improved.

[0038] In a second aspect of the invention, there is provided a reusable injector device for use with a cartridge, the cartridge comprising a cassette outer housing containing a pre-filled syringe and a needle cover, the reusable injector device comprising: a housing; a needle cover shuttle displaceable within the housing against a needle cover shuttle spring; and a plunger rod configured to dispense medicament from the pre-filed syringe in use; wherein, when the cartridge and the reusable injector device are coupled, the needle cover shuttle engages the needle cover of the cartridge to bias the needle cover in a proximal direction.

[0039] Therefore, a injector device is provided which can be reused with multiple disposable cartridges, reducing waste compared to an injector device with an integrated cartridge. Furthermore, the invention improves safety by ensuring that the needle cover of a cartridge is automatically biased by the needle cover shuttle spring to cover a needle in the cartridge, wherein this biasing is simply and intuitively initiated by a user coupling the cartridge to the reusable injector device. The reusable injector device may be configured to couple to the cassette outer housing of the cartridge.

[0040] In this way, the device is intuitively and simply assembled, with minimal modifications to the cartridge required.

[0041] The reusable injector device may comprise at least one interlock arm displaceable to engage a respective recess in the cassette outer housing to couple the reusable injector device to the cartridge.

[0042] Therefore, a simple mechanism for coupling a cartridge to the reusable injector device is provided, improving safety.

[0043] The at least one interlock arm may be arranged to be displaced towards the respective recess responsive to displacement of the plunger rod during delivery of medicament.

[0044] Therefore, a simple mechanism for ensuring coupling of a cartridge to the reusable injector device during delivery of medicament is provided, improving safety.

[0045] The plunger rod may comprise at least one recess to receive an outer end of the at least one interlock arm, wherein the at least one recess and the at least one interlock arm may be arranged such that proximal translation of the plunger rod disengages the outer end of the at least one interlock arm from the at least one recess to displace the at least one interlock arm for engaging the recess in the cassette outer housing.

[0046] Therefore, a simple mechanism for ensuring coupling of the cartridge to the reusable injector device during delivery of medicament is provided, improving safety.

[0047] Uncoupling of the cartridge from the reusable injector device may be inhibited during delivery of medicament.

[0048] In this way, safety of the system may be improved.

[0049] The reusable injector device may be configured such that, when the reusable injector device is coupled to the cartridge and the needle cover is displaced distally, a distal end of the needle cover is received within the housing and the needle cover displaces the needle cover shuttle distally against the bias of the needle cover shuttle spring.

[0050] Therefore, a simple and intuitive mechanism for charging the needle cover shuttle spring is provided.

[0051] The reusable injector device may comprise an unlocking element configured to engage with a needle cover locking mechanism of the cartridge once the cartridge is coupled to the reusable injector device to allow for rotation of the needle cover with respect to the cassette outer housing.

[0052] Therefore, a simple and intuitive mechanism for unlocking the needle cover for rotation once the cartridge and reusable injector device is provided, improving safety.

[0053] The reusable injector device may further comprise a plunger rod driving mechanism for driving the plunger rod.

[0054] By providing the plunger rod driving mechanism in the reusable injector device, the reusable injector device may be reused to deliver medicament from multiple cartridges, thereby reducing wastage.

[0055] In a third aspect of the invention, there is provided a cartridge for use with a reusable injector device, the cartridge comprising: a cassette outer housing; a pre-filled syringe arranged within cassette outer housing, the pre-filled syringe comprising a needle; and a needle cover arranged within the cassette outer housing and surrounding the pre-filled syringe.

[0056] Therefore, a cartridge for use with a reusable injector device is provided. By providing a simple, single-use cartridge that is easy to manufacture and has few components, many of the remaining components required for a medicament delivery process to be performed can be integrated into the reusable injector device, thereby reducing wastage.

[0057] Furthermore, provision of a needle cover in the cartridge ensures user safety before, during and after coupling of the cartridge to the reusable injector device. The needle cover may be configured to be engaged by a needle cover shuttle of the reusable injector device to bias the needle cover in a proximal direction, when the cartridge and the reusable injector device are coupled.

[0058] In this way the act of combing the cartridge and device at least partially charges the needle cover shuttle spring, making for a simple and reliable medicament delivery system.

[0059] The cartridge may be configured such that, when the cartridge is coupled to the reusable injector device, the needle cover is configured to be translated distally within the cassette outer housing from a primed position, in which the needle is surrounded by the needle cover, to a dose delivery position, in which at least a proximal end of the needle extends proximally outside of the needle cover for injection into an injection site.

[0060] Therefore, an intuitive mechanism for exposing a needle during an injection process is provided.

[0061] When the cartridge and the reusable injector device are coupled, the needle cover may be configured to be translated proximally within the cassette outer housing from the dose delivery position to a post-dose delivery position, in which the needle does not extend proximally outside of the needle cover.

[0062] Therefore, the needle is re-covered after dose delivery and safety of the system is improved.

[0063] After the needle cover has moved from the dose delivery position to the post-dose delivery position, distal movement of the needle cover is inhibited by a needle cover return lock.

[0064] In this way, a user may be further prevented from accidentally contacting the needle, and so safety of the system may be increased.

[0065] The needle cover return lock may comprise a needle cover locking arm extending from the needle cover and a locking recess arranged in the cassette outer housing, the needle cover locking arm configured to become engaged with the locking recess to inhibit distal movement of the needle cover. Therefore, a simple mechanism for improving safety of the system is provided.

[0066] The needle cover may be configured to be rotated within the cassette outer housing from an initial position to the primed position, and distal translation of the needle cover within the cassette outer housing may be inhibited when the needle cover is in the initial position.

[0067] By inhibiting distal translation of the needle cover until the needle cover has first been rotated by a user, accidental exposure of the needle may be prevented and therefore safety of the system may be increased.

[0068] The cartridge may further comprise a cap coupled to the cassette outer housing, wherein rotation of the needle cover from the initial position to the primed position is responsive to removal of the cap from the cassette outer housing.

[0069] Therefore, an intuitive mechanism for rotating the needle cover is provided, with the needle cover being rotated as the cap is removed.

[0070] The cartridge may be configured such that the cap cannot be removed from the cassette outer housing without rotating the needle cover.

[0071] Therefore, an intuitive mechanism for rotating the needle cover is provided.

[0072] The cap may comprise a guide pin configured to be received in a track formed in the cassette outer housing, the guide pin configured to traverse the track during removal of the cap.

[0073] Therefore, a simple mechanism for controlling removal of the cap is provided.

[0074] Rotation of the needle cover from the initial position to the primed position may be inhibited until the cartridge is coupled to the reusable injector device.

[0075] Therefore, safety of the cartridge is increased, since a user will be inhibited from removing the cap and rotating the needle cover until the cartridge has been coupled to the reusable injector device, thereby preventing accidental needle exposure. Rotation of the needle cover from the initial position to the primed position may be inhibited by a needle cover locking mechanism of the cartridge, and the needle cover locking mechanism may be configured to be engaged by an unlocking element of the reusable injector device when the cartridge is coupled to the reusable injector device, to unlock the needle cover for rotation.

[0076] Therefore, a simple mechanism for controlling rotation of the needle cover based on coupling of the cartridge to the reusable injector device is provided.

[0077] The needle cover locking mechanism may comprise a clip configured to releasably engage with the needle cover to inhibit rotation of the needle cover.

[0078] Therefore, a simple mechanism for controlling rotation of the needle cover based on coupling of the cartridge to the reusable injector device is provided.

[0079] In a fourth aspect of the invention, there is provided a method of using any medicament delivery system as described herein, the method comprising coupling the cartridge to the reusable injector device.

[0080] BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, in which:

[0082] FIG. 1 is a perspective view of a medicament delivery system according to embodiments of the present invention, showing a cartridge coupled to a reusable injector device;

[0083] FIG. 2 is a cross-sectional perspective view of the medicament delivery system of FIG. 1; FIG. 3 is a cross-sectional perspective view of the medicament delivery system of FIG. 2 showing the cartridge and a proximal end of the reusable injector device prior to coupling of the cartridge to the reusable injector device, showing the cartridge comprising a needle cover locking mechanism and needle cover in an initial position;

[0084] FIGS. 4A-C are alternative perspective views of the needle cover locking mechanism shown in FIG. 3;

[0085] FIG. 5 is a cross-sectional perspective view of the medicament delivery system of FIG. 3 showing the cartridge and a proximal end of the reusable injector device after coupling of the cartridge to the reusable injector device; FIGS. 6A-C are alternative perspective views of the needle cover locking mechanism shown in FIG. 5 interacting with the unlocking element of the reusable injector device; FIG. 7A is a schematic side view of the needle cover locking mechanism and unlocking element of FIG. 5, prior to complete coupling of the cartridge and the reusable injector device;

[0086] FIG. 7B is a schematic side view of the needle cover locking mechanism and unlocking element of FIG. 7A, after coupling of the cartridge and the reusable injector device is complete;

[0087] FIG. 8 is a cross-sectional side view of the medicament delivery system of FIG. 5;

[0088] FIG. 9 is a cross-sectional perspective view of the medicament delivery system of FIG. 5 after the needle cover has been rotated to its primed position by rotation of a cap, showing a needle cover return lock and needle cover locking mechanism;

[0089] FIG. 10A is a perspective view of a proximal end of a cartridge showing a cap attached to the proximal end of the cassette outer housing, when the needle cover is in its initial state;

[0090] FIG. 10B is a cross-sectional side view of the proximal end of the cartridge of FIG. 10A, showing the cap attached to the proximal end of the cassette outer housing, when the needle cover is in its initial state;

[0091] FIG. 10C is a perspective view of the proximal end of the cartridge of FIG. 10A after the cap has been rotated;

[0092] FIG. 10D is a cross-sectional side view of the proximal end of the cartridge of FIG. 10C, showing the needle cover having been rotated to its primed position in response to rotation by the cap;

[0093] FIG. 10E is a perspective view of the cap and the proximal end of the cassette outer housing of FIG. 10C, once the cap has been pulled axially away from the cassette outer housing in a proximal direction to uncouple the cap from the cassette outer housing;

[0094] FIG. 10F is a cross-sectional side view of the cap and the proximal end of the cassette outer housing of FIG. 10C, showing the needle cover in its primed position;

[0095] FIG. 10G is a perspective view of the proximal end of the cassette outer housing of FIG. 10E, after the cap has been removed from the cassette outer housing to reveal the proximal end of the needle cover;

[0096] FIG. 10H is a side view of the proximal end of the cassette outer housing and the needle cover of FIG. 10G, showing a cap blocking element formed on the needle cover;

[0097] FIG. 11A is a perspective view showing the needle cover return lock of FIG. 9 in closer detail;

[0098] FIG. 11 B is a perspective view of the needle cover locking mechanism of FIG. 9 in closer detail; FIG. 110 is an alternative perspective view of the needle cover locking mechanism of FIG. 11B;

[0099] FIG. 12 is a cross-sectional perspective view of the medicament delivery system of FIG. 9 after the needle cover has been axially translated in a distal direction to its dose delivery position in response to pushing of the needle cover on an injection site;

[0100] FIG. 13A is a cross-sectional side view of the medicament delivery system of FIG. 12;

[0101] FIG. 13B is magnified cross-sectional side view of a portion of the medicament delivery system of FIG. 13A, showing a needle cover locking arm in detail;

[0102] FIG. 14 is a perspective view of a portion of the medicament delivery system of FIG. 12 showing a cassette arm;

[0103] FIG. 15 is a front view of a portion of the medicament delivery system of FIG. 12 showing a interlock arm of the reusable injector device interacting with the cassette outer housing of the cartridge to couple the cartridge to the reusable injector device;

[0104] FIG. 16 is a cross-sectional perspective view of the medicament delivery system of FIG. 12 after the plunger rod has been axially translated to dispense a dose of medicament;

[0105] FIG. 17 is a cross-sectional side view of the medicament delivery system of FIG. 16;

[0106] FIG. 18 is a perspective view of a portion of the medicament delivery system of FIG. 16 showing the cassette arm;

[0107] FIG. 19 is a front view of a portion of the medicament delivery system of FIG. 16 showing the interlock arm of the reusable injector device further interacting with the cassette outer housing of the cartridge to couple the cartridge to the reusable injector device;

[0108] FIG. 20 is a cross-sectional perspective view of the medicament delivery system of FIG. 16 after dose delivery is complete and the medicament delivery system has been removed from the injection site, causing the needle cover to be axially translated in a proximal direction out of the cassette outer housing into its post-dose delivery state by a biasing force from a needle cover shuttle and needle cover shuttle spring located in the reusable injector device;

[0109] FIG. 21 is a cross-sectional side view of the medicament delivery system of FIG. 20;

[0110] FIG. 22 is a side view of a portion of the medicament delivery system of FIG. 21 , showing the needle cover locking arm in greater detail;

[0111] FIG. 23 is a perspective view of a portion of the medicament delivery system of FIG. 21 , showing the needle cover locking arm in greater detail;

[0112] FIG. 24 is a front view of a portion of the medicament delivery system of FIG. 20 showing the interlock arm of the reusable injector device interacting with the cassette outer housing of the cartridge to couple the cartridge to the reusable injector device; FIG. 25 is a cross-sectional perspective view of the medicament delivery system of FIG. 20 after the plunger rod has been axially retracted in a distal direction back into the reusable injector device;

[0113] FIG. 26 is a cross-sectional side view of the medicament delivery system of FIG. 25;

[0114] FIG. 27 is a front view of a portion of the medicament delivery system of FIG. 25 showing the interlock arm of the reusable injector device interacting with the cassette outer housing of the cartridge to couple the cartridge to the reusable injector device;

[0115] FIG. 28 is a cross-sectional perspective view of the medicament delivery system of FIG. 25 after the cartridge has been uncoupled from the reusable injector device;

[0116] FIGS. 29A-D are perspective views showing sequential movements of the needle cover locking arm during an injection process;

[0117] FIG. 30 is a schematic perspective view showing an alternative mechanism for locking the needle cover in its post-dose delivery position, using a rotatable collar, in accordance with embodiments of the present disclosure;

[0118] FIG. 31A is a schematic perspective view showing an alternative mechanism for locking the needle cover in its post-dose delivery position, using a shifting ramp, and with the needle cover in its primed position, in accordance with embodiments of the present disclosure;

[0119] FIG. 31 B is a schematic perspective view of the mechanism of FIG. 31 A, after the needle cover has moved from its primed position to its dose delivery position;

[0120] FIG. 31 C is a schematic perspective view of the mechanism of FIG. 31 B, as the needle cover is moving from its dose delivery position to its post-dose delivery position;

[0121] FIG. 31 D is a schematic perspective view of the mechanism of FIG. 31 B, once the needle cover is in its post-dose delivery position;

[0122] FIG. 32 is a schematic perspective view showing an alternative mechanism for locking the needle cover in its post-dose delivery position, using a pin and guide channel, in accordance with embodiments of the present disclosure;

[0123] FIG. 33 is a perspective view of a proximal end of a cartridge showing an alternative mechanism for removing the cap, whereby the cap is removed by twisting relative to the cassette outer housing, in accordance with embodiments of the present disclosure;

[0124] FIG. 34 is a perspective view of a proximal end of a cartridge showing an alternative mechanism for removing the cap, whereby the cap is removed by pulling the cap away from the cassette outer housing, in accordance with embodiments of the present disclosure; FIG. 35A is a partial perspective view of the proximal end of the reusable injector device of FIG. 5, showing an interaction between the interlock arms and the distal end of the cassette outer housing to couple the cartridge to the reusable injector device;

[0125] FIG. 35B and FIG. 35C are magnified perspective views of one of the interlock arms of FIG. 35A, showing interaction with the distal end of the cassette outer housing;

[0126] FIG. 36 is a perspective illustration of a cartridge and reusable injector device according to embodiments of the present disclosure, in which the cartridge and reusable injector device may be coupled using a threaded connection;

[0127] FIG. 37 is a perspective illustration of a cartridge and reusable injector device according to embodiments of the present disclosure, in which the cartridge and reusable injector device may be coupled using a bayonet connection;

[0128] FIG. 38A is a schematic side view showing interactions between the plunger rod, interlock arms and cassette outer housing of the medicament delivery system of FIG. 5, prior to proximal translation of the plunger rod;

[0129] FIG. 38B is a schematic side view showing interactions between the plunger rod, interlock arms and cassette outer housing of the medicament delivery system of FIG. 16, with the plunger rod extended;

[0130] FIG. 39 is a side view of cartridge coupled to a proximal portion of a reusable injector device according to embodiments of the present disclosure, showing an indicator system;

[0131] FIG. 40A is a cutaway side view of the cartridge shown in FIG. 39, but with the cap attached to the cassette outer housing and the needle cover in its initial position;

[0132] FIG. 40B is a cutaway side view of the cartridge shown in FIG. 40A once the cap has been removed and the needle cover is in its primed position;

[0133] FIG. 40C is a cutaway side view of the cartridge shown in FIG. 40B once an injection process has been performed and the needle cover is in post-dose delivery position;

[0134] FIG. 41A is a side view of a medicament delivery system comprising the cartridge and reusable injector device of FIG. 39, showing the cartridge and reusable injector device before they have been coupled;

[0135] FIG. 41 B is a side view of the medicament delivery system of FIG. 41 A, after the cartridge and reusable injector device have been coupled;

[0136] FIG. 41 C is a side view of the medicament delivery system of FIG. 41 B, after the cap has been removed and the needle cover has been moved to its primed position;

[0137] FIG. 41 D is a side view of the medicament delivery system of FIG. 41 C, after the needle cover has been pressed against an injection site, causing the needle cover to move to its dose delivery position, the needle to be exposed, and a dose delivery to be initiated; FIG. 41 E is a side view of the medicament delivery system of FIG. 41 D, after dose delivery is complete and the needle cover has been removed from the injection site, causing the needle cover to be pushed out of the cassette outer housing by the needle cover shuttle to cover the needle;

[0138] FIG. 42 is a flowchart illustrating a method of using a medicament delivery system according to aspects of the present disclosure; and

[0139] FIG. 43 is a flowchart illustrating another method of using a medicament delivery system according to aspects of the present disclosure.

[0140] DETAILED DESCRIPTION

[0141] A drug delivery device, such as a medicament delivery system, as described herein, may be configured to inject a medicament into a patient. For example, delivery could be subcutaneous, intra-muscular, or intravenous. Such a device could be operated by a patient or care-giver, such as a nurse or physician, and can include various types of safety syringe, pen-injector, or auto-injector. The device can include a cartridge-based system that requires piercing a sealed ampule before use. Volumes of medicament delivered with these various devices can range from about 0.5 ml to about 2 ml. Yet another device can include a large volume device (“LVD”) or patch pump, configured to adhere to a patient’s skin for a period of time (e.g., about 5, 15, 30, 60, or 120 minutes) to deliver a “large” volume of medicament (typically about 2 ml to about 10 ml).

[0142] In combination with a specific medicament, the presently described devices may also be customized in order to operate within required specifications. For example, the device may be customized to inject a medicament within a certain time period (e.g., about 3 to about 20 seconds for auto-injectors, and about 10 minutes to about 60 minutes for an LVD). Other specifications can include a low or minimal level of discomfort, or to certain conditions related to human factors, shelf-life, expiry, biocompatibility, environmental considerations, etc. Such variations can arise due to various factors, such as, for example, a drug ranging in viscosity from about 3 cP to about 50 cP. Consequently, a drug delivery device will often include a hollow needle ranging from about 25 to about 31 Gauge in size. Common sizes are 27 and 29 Gauge.

[0143] The delivery devices described herein can also include one or more automated functions. For example, one or more of needle insertion, medicament injection, and needle retraction can be automated. Energy for one or more automation steps can be provided by one or more energy sources. Energy sources can include, for example, mechanical, pneumatic, chemical, or electrical energy. For example, mechanical energy sources can include springs, levers, elastomers, or other mechanical mechanisms to store or release energy. One or more energy sources can be combined into a single device. Devices can further include gears, valves, or other mechanisms to convert energy into movement of one or more components of a device.

[0144] The one or more automated functions of an auto-injector may each be activated via an activation mechanism. Such an activation mechanism can include one or more of a button, a lever, a needle sleeve, or other activation component. Activation of an automated function may be a one-step or multi-step process. That is, a user may need to activate one or more activation components in order to cause the automated function. For example, in a one-step process, a user may depress a needle sleeve against their body in order to cause injection of a medicament. Other devices may require a multi-step activation of an automated function. For example, a user may be required to depress a button and retract a needle shield in order to cause injection.

[0145] In addition, activation of one automated function may activate one or more subsequent automated functions, thereby forming an activation sequence. For example, activation of a first automated function may activate at least two of needle insertion, medicament injection, and needle retraction. Some devices may also require a specific sequence of steps to cause the one or more automated functions to occur. Other devices may operate with a sequence of independent steps.

[0146] Some delivery devices can include one or more functions of a safety syringe, pen-injector, or auto-injector. For example, a delivery device could include a mechanical energy source configured to automatically inject a medicament (as typically found in an autoinjector) and a dose setting mechanism (as typically found in a pen- injector).

[0147] Embodiments of the present invention provide a reusable injector device, a cartridge for use with the reusable injector device, and a medicament delivery system comprising the cartridge and the reusable injector device.

[0148] The cartridge holds a pre-filled syringe containing a medicament and can be coupled to the reusable injector device for injecting a dose of the medicament into a patient. After a dose of medicament has been injected, the cartridge may be uncoupled from the reusable injector device and safely discarded, leaving the reusable injector device ready for use with a new cartridge. By splitting the medicament delivery system into a reusable injector device and a removable cartridge, relatively high-value components of the medicament delivery system may be incorporated into the reusable injector device while relatively low value components or components may be incorporated into the cartridge, which may be disposed after use. Embodiments of the present invention also relate to improving the safety of cartridge both when it is separated from the reusable injector device and when it is coupled to the reusable injector device, reducing the possibility of a user unintentionally contacting a needle.

[0149] In the context of this application, the terms "proximal" and “distal” herein respectively refer to as relatively closer to the injection site and relatively further away from the injection site. Like reference numerals refer to like features throughout.

[0150] The present invention relates to a medicament delivery system 10 comprising a reusable injector device 100 and a cartridge 200 for use with the reusable injector device 100. FIGS. 1 to 43 represent exemplary embodiments of the invention.

[0151] In the foregoing description, the terms ‘square’ and ‘ramped’ are used. Respectively, square and ramped refer to planar surfaces that extend perpendicular and obliquely to the longitudinal axis of the medicament delivery system 10 (or the cartridge 200 or the reusable injector device 100, where appropriate). The term ‘lateral’ as used herein refers to being substantially parallel to the longitudinal axis of the medicament delivery system 10 (or the cartridge 200 or the reusable injector device 100, where appropriate).

[0152] FIG. 1 shows a medicament delivery system 10 in accordance with one or more embodiments of the present disclosure. The medicament delivery system 10 is generally cylindrical, having a longitudinal axis Xs-Xs with a proximal end P to be placed at an injection site and a distal end D at the opposite end of the medicament delivery system 10, away from the injection site.

[0153] The cartridge 200 is removably couplable to the reusable injector device 100, as shown in FIGS. 41A-E. In other words, the cartridge 200 and reusable injector device 100 may be coupled and uncoupled from each other, the cartridge 200 and reusable injector device 100 being combinable for medicament delivery and separable thereafter. FIG. 1 shows the cartridge 200 when coupled to the reusable injector device 100. The cartridge 200 and the reusable injector device 100 each have a respective longitudinal axis that is coaxial with the longitudinal axis Xs-Xsof the medicament delivery system 10 when the cartridge 200 and the reusable injector device 100 are coupled together as shown in FIG.1 . The cartridge 200 and the reusable injector device 100 are therefore coaxially aligned with the longitudinal axis Xs-Xs when coupled together, with the cartridge 200 adjacent to the reusable injector device 100 along the longitudinal axis Xs-Xs such that a distal end of the cartridge is coupled to a proximal end of the reusable injector device 100. The reusable injector device 100 forms the distal end of the medicament delivery system 10 and the cartridge 200 forms the proximal end of the medicament delivery system 10. The medicament delivery system 10 may take the form of a pen injector when the cartridge 200 and the reusable injector device 100 are coupled together, although other forms are envisaged.

[0154] The cartridge 200 and the reusable injector device 100 may be coupled using any suitable coupling arrangement, including those described throughout this disclosure. The coupling arrangement allows the cartridge 200 and reusable injector device 100 to be uncoupled after a medicament delivery so that the cartridge 200 can be disposed of.

[0155] The cartridge 200 is a single-use component that can be attached to the reusable injector device 100 to administer a dose of medicament to a patient. The cartridge 200 comprises a cassette outer housing 210, a pre-filled syringe 230, a needle cover 240 and a cap 260, each of which have a generally cylindrical form and are arranged coaxially along the longitudinal axis Xs-Xs of the medicament delivery system 10 and the cartridge 200.

[0156] The pre-filled syringe 230 is received within an internal bore 213 of the cassette outer housing 210 and extends along its length. The pre-filled syringe 230 may be coupled to the cassette outer housing 210 by any suitable holding arrangement such that the prefilled syringe 230 is inhibited from moving axially along longitudinal axis Xs-Xs with respect to the cassette outer housing 210. The holding arrangement may also prevent radial and / or rotational movement of the pre-filled syringe 230 relative to the cassette outer housing 210. The cassette outer housing 210 may have a window 215 through which the pre-filled syringe 230 may be visible to a user, for example so that a user may view the amount of medicament remaining in the pre-filled syringe 230.

[0157] The cap 260 is coupled to the cassette outer housing 210 and comprises a tubular wall

[0158] 261 that is open at a distal end and closed at the opposite, proximal end by an end wall 262. The end wall 262 is partially removed in FIG. 1 so that components inside the cap

[0159] 260 may be seen. FIG. 1 shows the cap 260 coupled to the proximal end of the cassette outer housing 210, surrounding the proximal end of the needle cover 240.

[0160] The needle cover 240 is located within the cassette outer housing 240, as described later in more detail with respect to FIG. 2.

[0161] FIG. 1 shows an aperture 243 formed in the needle cover 240 through which an injection will take place. This aperture 243 would in reality be obscured behind the end wall 262 of the cap 260.

[0162] The reusable injector device 100 comprises a housing 110 having a generally cylindrical form that contains various components as described later. The reusable injector device 100 is coaxial with the axis Xs-Xs, distal to the cartridge 200.

[0163] FIG. 2 shows a cross-sectional view of the medicament delivery system 10 of FIG. 1 , showing various components aligned with respect to the axis Xs-Xs. The longitudinal axis of the cartridge 200 and the longitudinal axis of the reusable injector device 100 are coaxial with the axis Xs-Xsshown in FIG. 2.

[0164] The pre-filled syringe 230 comprises a cylindrical vial 231 filled with medicament, a bung 232, a needle 233, a rigid needle shield (RNS) 234 and a piston 235. The bung 232 seals the proximal end of the vial 231 and the piston 235 the distal end. The needle 233 extends through the bung 232 and into the vial 231. The piston 235 is configured for proximal displacement through the vial 231 parallel to the axis Xs-Xs during operation of the medicament delivery system 10, to dispense a dose of the medicament through the needle 233 and into an injection site.

[0165] The needle 233 is enclosed by the optional RNS 234. The RNS 234 is a cylindrical block of protective material with a cavity in which the needle 233 extends. The RNS 234 may be tightly fitted within an internal RNS holder (not shown) of the cap 260 so that the RNS 234 is removed with the cap 260 when the cap 260 is removed from the cassette outer housing 210. The removal of the RNS 234 may be via the aperture 243.

[0166] The cassette outer housing 210 has a proximal opening 216 at its proximal end for receiving the cap 260 and a distal opening 217 at its distal end for receiving the reusable injector device 100 when the cartridge 200 and reusable injector device 100 are coupled.

[0167] The pre-filled syringe 230 is held within the internal bore 213 of the cassette outer housing 210 by a pre-filled syringe holder 214, which may be coupled to an inner surface of the cassette outer housing 210 and to the pre-filled syringe 230. The pre-filled syringe holder 214 maintains the pre-filled syringe 230 within a fixed axial and radial position within the cassette outer housing 210. FIG. 2 shows one example form of the pre-filled syringe holder 214 wherein the pre-filled syringe 230 is coupled at a distal end and a proximal end by the pre-filled syringe holder 214, however it should be understood that any other suitable form of a pre-filled syringe holder 214 may be used instead.

[0168] The pre-filled syringe 230 is arranged within the cassette outer housing 210 such that at least a portion of the proximal end of the needle 233 extends beyond the proximal end of the cassette outer housing 210, through the proximal opening 216 of the cassette outer housing 210. This allows the needle 233 to penetrate an injection site once the cap 260 has been removed from the cartridge 200 and the needle cover 240 has been retracted into the cassette outer housing 210 from a primed position to a dose delivery position, as described later.

[0169] The needle cover 240 is located within the cassette outer housing 210, extending parallel to the axis Xs-Xs of the medicament delivery system 10 and along most of the axial length of the cassette outer housing 210. The needle cover 240 extends through the internal bore 213, between an inner surface of the cassette outer housing 210 and the pre-filed syringe 230.

[0170] A proximal end of the needle cover 240 extends outside of the cassette outer housing 210, through the proximal opening 216 of the cassette outer 210 housing in a proximal direction, to surround the proximal end of the needle 233. The needle 233 does not extend beyond the needle cover 240 in the proximal direction when the needle cover 240 is in its initial position as shown in FIG. 2 or its primed position or post-delivery positions described later. The proximal end of the needle cover 240 comprises a tubular wall 241 with an end wall 242 covering the proximal end of the tubular wall 241. The tubular wall 241 surrounds the needle 233 when the needle cover 240 is in its initial position relative to the cassette outer housing 210 as shown in FIG. 2. The end wall 242 has an aperture 243 formed therethrough, the aperture 243 aligned with the axis Xs-Xs and the needle 233 so that at least a proximal end of the needle 233 passes though the aperture 243 during an injection process, once the needle cover 240 has been retracted from its dose delivery position within the cassette outer housing 210, as described later in relation to at least FIG. 12. The distal end of the needle cover 240 is adjacent the distal end of the cassette outer housing 210 such that it engages the reusable injector device 100 when the cartridge 200 is coupled to the reusable injector device 100, as described later.

[0171] The cap 260 covers the proximal end of the needle cover 240 that extends outside the cassette outer housing 210, so that the needle cover 240 cannot be accessed by a user from the proximal end of the cartridge 200 while the cap 260 remains attached to the remainder of the cartridge 200.

[0172] The tubular wall 261 of the cap 260 comprises a proximal portion 263 arranged to cover the proximal end of the needle cover 240 and a distal portion 264 extending distally from the proximal portion, the distal portion 262 to be received with the proximal end of the cassette outer housing 210.

[0173] The proximal portion 263 of the cap 260 extends axially from the proximal end of the cassette outer housing 210, beyond the proximal end of the needle cover 240. The proximal portion 263 of the cap 260 has a greater diameter that the distal portion 264 of the cap 260, leading to an annular shoulder 265 being formed between the proximal portion 263 and the distal portion 264 of the cap 260. The distal portion 264 has a diameter equal to or slightly smaller than the diameter of the proximal opening 216 of the cassette outer housing 210, allowing the distal portion 264 to be tightly received within the proximal opening 216 of the cassette outer housing 210 when the cap 260 is coupled to the cassette outer housing, as shown in FIG. 2. When the cap is 260 is coupled to the cassette outer housing 210, the annular shoulder 265 abuts the proximal end surface of the cassette outer housing 210. The diameter of the proximal portion of the cap 260 is greater than the diameter of the proximal opening 216 formed at the proximal end of the cassette outer housing 210, thereby inhibiting insertion of the proximal portion 263 of the cap 260 into the cassette outer housing 210. When the cap 260 is coupled to the cassette outer housing 210, the distal portion 264 of the cap 260 extends between the inner surface of the cassette outer housing 210 and the needle cover 240.

[0174] FIG. 2 also shows the reusable injector device 100 in cross-section. The reusable injector device 100 comprises a housing 110, a needle cover shuttle 120 and associated needle cover shuttle spring 121, and a plunger rod 170, each aligned with the longitudinal axis Xs-Xs of the medicament delivery system 10. The reusable injector device 10 may further comprise a plunger rod driving mechanism 180 for driving the plunger rod 170 axially in the proximal direction. Any suitable plunger rod driving mechanism 180 may be used. The housing 110 of the reusable injector device 100 comprises a tubular wall 111 that is open at its proximal end and closed by an end wall (not shown) at its distal end. The outer surface of the tubular wall 111 forms the outer surface of the reusable injector device 100 which is, therefore, cylindrical in appearance.

[0175] The proximal end of the housing 100 is configured to receive the distal end of the cassette outer housing 210 of the cartridge 200 when the cartridge 200 is coupled to the reusable injector device 100.

[0176] The housing 110 contains a plunger rod guide sleeve 171 coupled to the tubular wall 111 and used to the plunger rod 170 during axial translation of the plunger rod 170 during dose delivery. The plunger rod guide sleeve 171 comprises a cylindrical channel 174 through which the plunger rod 170 is retained and guided. The cylindrical channel 174 is coaxial with the longitudinal axis Xs-Xs, allowing the plunger rod 170 to translate through the cylindrical channel 174 along the longitudinal axis Xs-Xs in a proximal direction during dose delivery and an opposite, distal direction during recharging of the plunger rod 170, after dose delivery. A distal surface 173 of the plunger rod guide sleeve 171 may be used to support the distal end of the pre-filled syringe 230 when a cartridge 200 is coupled to the reusable injector device 210.

[0177] An annular cavity 172 is formed between the outer surface of the plunger rod guide sleeve 171 and the inner surface of the tubular wall 111 , the annular cavity 172 coaxial with the longitudinal axis Xs-Xs. The needle cover shuttle spring 121 is housed within the annular cavity 172. The needle cover shuttle spring 121 is shown in FIG. 2 as a helical coil spring arranged within the annular cavity 172 such that it surround the plunger rod guide sleeve 171 , with the longitudinal axis of the needle cover shuttle spring 121 coaxial with the longitudinal axis Xs-Xs of the medicament delivery system 10. It can be seen in FIG. 2 that the plunger rod 170, plunger rod guide sleeve 171 , needle cover shuttle spring 121 and tubular wall 111 are all coaxial with the longitudinal axis Xs-Xs of the medicament delivery system 10, with the plunger rod 170 aligned along the axis Xs-Xs, the plunger rod guide sleeve 171 surrounding the plunger rod 171 , the needle cover shuttle spring 121 surrounding the plunger rod guide sleeve 171 , and the tubular wall 111 surrounding the needle cover shuttle spring 121.

[0178] The needle cover shuttle 120 is received within the housing 110 of the reusable injector device 100, adjacent the proximal end of the housing 110. The needle cover shuttle 120 is configured to translate axially in both proximal and distal directions within the annular cavity 172 of the housing 110, along the axis Xs-Xs. FIG. 2 shows the needle cover shuttle 120 at its most proximal axial position relative to the housing 110.

[0179] The needle cover shuttle 120 comprises an annular wall 122 and a flange 124, both of which are coaxial with the axis Xs-Xs of the medicament delivery system 10. The flange 124 projects radially outwards from the outer surface of the annular wall 122, at a distal end of the annular wall 122. The flange 124 is located within the annular cavity 172, with the annular wall 122 extending in a proximal direction from the flange 124. The outer surface of the flange 124 may be in abutment with the inner surface of the tubular wall 111 of the housing 110, allowing the tubular wall 111 to act as a guide for the flange 124 and the needle cover shuttle 120 as the needle cover shuttle 120 is translated proximally and distally with respect to the tubular housing 110, along the longitudinal axis Xs-Xs. The annular wall 122 surrounds a proximal end portion of the plunger rod guide sleeve 171 , with the proximal end portion of the plunger rod guide sleeve 171 also acting as a guide for the axial translation of the needle cover shuttle 120.

[0180] A proximal end of the needle cover shuttle spring 121 abuts the distal surface of the flange 124. The distal end of the needle cover shuttle spring 121 abuts a spring blocking element 123 within the housing 110, which may be formed from a distal portion of the plunger rod guide sleeve 171. The spring blocking element 123 inhibits distal movement of the distal end of the needle cover shuttle spring 121 . The needle cover shuttle spring 121 provides a biasing force to the needle cover shuttle 120 in the proximal direction. In FIG. 2 this is achieved by needle cover shuttle spring 121 being tensioned such that the proximal end of the needle cover shuttle spring 121 engages the distal surface of the flange 124 and biases the flange 124 in the proximal direction.

[0181] While FIG. 2 shows the needle cover shuttle spring 121 in the form of a helical coil spring arranged coaxially about the axis Xs-Xs of the medicament delivery system 10, it should be noted that a different type of biasing means may be used for the needle cover shuttle spring 121 such as a leaf spring, a disc spring, or another type of spring, a resilient material such as rubber, or a means of magnetic repulsion. Furthermore, any suitable arrangement of the biasing means within the housing 110 may be used, as long as the biasing means is able to provide a biasing force to the needle cover shuttle 120 in the proximal direction.

[0182] The flange 124 limits translational movement of the needle cover shuttle 120 in the proximal direction relative to the housing 110 by being brought into engagement with a shuttle blocking element 112 projecting from the inner surface of the proximal end of the housing 110, once the needle cover shuttle 120 has reached a maximal extent of proximal travel in the housing 110. The shuttle blocking element 112 may be formed as an annular projection around the inner surface of the tubular wall 111 , however any other suitable configuration may be used. A proximal surface of the shuttle blocking element 112 may also contact a distal end of the cassette outer housing 110 when the cartridge 200 is coupled to the cassette outer housing 110, limiting distal axial movement of the cartridge 200 into the reusable injector device 100.

[0183] The needle cover shuttle 120 is arranged to engage with the distal end of the needle cover 240 when the cartridge 200 is coupled to the reusable injector device 100, biasing the needle cover 240 in the proximal direction. More particularly, the proximal surface of the annular wall 122 of the needle cover shuttle 120 is configured to engage the distal surface of the needle cover 240 when the cartridge 200 is coupled to the reusable injector device 100, with the needle cover shuttle spring 120 biasing the needle cover shuttle 120 in the proximal direction, which in turn biases the needle cover 240 in the proximal direction.

[0184] The plunger rod 170 is configured to engage and displace the piston 235 of the pre-filled syringe 230 in the proximal direction during an injection so as to eject medicament out of the vial 231 through the needle 233. Any suitable mechanism for axially translating the plunger rod 170 may be used as the plunger rod driving mechanism 180. For example, the plunger rod driving mechanism 180 may comprise a plunger drive spring (not shown) such as a helical or torsion spring which can impart a force to the plunger rod 170 in a proximal direction, driving the plunger rod 170 proximally. In other examples, an electromechanical driving mechanism such as a motor may be used to move the plunger rod 170. In other examples, the plunger rod driving system 180 may be powered using compressed gas or fluid.

[0185] The needle cover 240 is movable from an initial position to a primed position, then to a dose delivery position, then to a post-dose delivery position, with each position being a position of the needle cover 240 with respect to the cassette outer housing 210.

[0186] To move the needle sleeve 240 from its initial position, shown in FIG. 2 and FIG. 5, to its primed position, shown in FIG. 9, the needle sleeve 240 is rotated about the longitudinal axis Xs-Xs relative to the cassette outer housing 210. Rotation of the needle cover 240 from the initial position to the primed position may be inhibited (prevented) while the cartridge 200 is uncoupled from the reusable injector device 100, for example by a needle cover locking mechanism 250. To allow the needle cover 240 to rotate from its initial position to its primed position, the cartridge 200 is coupled by a user to the reusable injector device 100. This may be achieved by an unlocking element 350 of the reusable injector device 100 engaging with the needle cover locking mechanism 250 once the cartridge 200 is coupled to the reusable injector device 100, with the engagement unlocking the needle cover locking mechanism 250 and allowing for rotation of the needle cover 240 with respect to the cassette outer housing 210.

[0187] Rotation of the needle cover 240 from the initial position to the primed position may be responsive to a user moving the cap 260 with respect to the cassette outer housing 210, for example during a cap removal process. This movement may be rotational about the axis Xs-Xs, translational along the axis Xs-Xs, or a combination of both. The movement of the cap 260 with respect to the cassette outer housing 210 may cause the needle cover 240 to be rotated from its initial position to its primed position, as described later in more detail. In some examples, the cap 260 may be inhibited from being removed from the cassette outer housing 210 until the needle cover 240 has been moved from its initial position to its primed position.

[0188] Axial translation of the needle cover 240 with respect to the cassette outer housing 210 may be inhibited while the needle cover 240 is in its initial position, for example also by the needle cover locking mechanism 250. In some examples, axial translation of the needle cover 240 is inhibited until the needle cover 240 has been rotated from its initial position to its primed position.

[0189] Once the cartridge 200 has been coupled to the reusable injector device 100 and the needle sleeve 240 has been rotated from its initial position to its primed position, return rotation back in the opposite direction from the primed position to the initial position may be inhibited, for example by a rotational stop element 280 as described later in relation to FIG. 9.

[0190] To move the needle sleeve 240 from its primed position, shown in FIG. 9, to its dose delivery position, shown in FIG. 12, the needle sleeve 240 is translated axially in a distal direction along the longitudinal axis Xs-Xs relative to the cassette outer housing 210, for example by pressing the proximal end of the needle cover 240 against an injection site. When the cartridge 200 is coupled to the reusable injector device 100, the needle cover 240 engages a needle cover shuttle 120 of the reusable injector device 100, which biases the needle cover 240 in a proximal axial direction. Moving the needle cover 240 from its primed position to its dose delivery position therefore requires counteracting the biasing force provided by the needle cover shuttle 120. Rotation of the needle sleeve 240 may remain inhibited while in its dose delivery position. This may again be achieved by the rotational stop element 280.

[0191] Delivery of a dose of medicament from the pre-filled syringe 230 may be performed while the needle cover 240 is in its dose delivery position, as described later. The dose delivery may be performed responsive to the needle cover 240 moving into its dose delivery position, or may be performed responsive to a separate action performed after the needle cover 240 has moved into its dose delivery position. In some examples, uncoupling of the cartridge 200 from the reusable injector device 100 may be inhibited while dose delivery is occurring, as described later.

[0192] To move the needle sleeve 240 from its dose delivery position, shown in FIG. 12, to its post-dose delivery position, shown in FIG. 20, the needle sleeve 240 is translated axially in a proximal direction along the longitudinal axis Xs-Xsrelative to the cassette outer housing 210. The needle cover 240 may be translated from the dose delivery position to the post-dose delivery position by the needle cover shuttle 120, due to the needle cover shuttle spring 121 providing a biasing force to the needle cover shuttle 120, which in turn provides the force to the needle cover 240. Movement of the needle cover 240 from the dose delivery position to the post-dose delivery position may therefore occur automatically once the user has removed the needle cover 240 from the injection site.

[0193] The axial location of the needle sleeve 240 with respect to the cassette outer housing 210 when the needle sleeve 240 is in its post-delivery position is substantially the same as the axial location of the needle sleeve 240 with respect to the cassette outer housing 210 when the needle sleeve 240 is in its initial position or primed position, however the rotational location of the needle sleeve 240 with respect to the cassette outer housing 210 may be different.

[0194] In some examples, once the needle cover 240 has moved to its post-dose delivery position, further axial translation of the needle cover 240 with respect to the cassette outer housing 210 may be inhibited, such as axial translation back in the distal direction. The inhibition may be provided by a needle cover return lock 310 of the cartridge 200. By preventing distal axial movement of the needle cover 240 once it has been moved into its post-delivery position, an unintentional uncovering of the needle 233 of the pre-filled syringe 230 may be prevented.

[0195] Movement of the needle sleeve 240 between the various positions will be described later in more detail. FIG. 3 shows the cartridge 200 of FIG. 2 and a proximal part of the reusable injector device 100 of FIG. 2 pre-use, that is, prior to attachment of the cartridge 200 to the reusable injector device 100. The cartridge 200 is therefore shown to be axially separated from the reusable injector device 100. Only a proximal portion of the reusable injector device 100 is shown, for the sake of clarity. The pre-filled syringe 230 and the majority of the cap 260 of FIG. 2 are also not shown in FIG. 3 so that other features of the cartridge 200 such as the needle cover 240 are not obscured. However, it should be understood that the cap 260 and pre-filled syringe 230 would indeed be present in the cartridge 200.

[0196] The needle cover 240 is shown in its initial position relative to the cassette outer housing 210 and pre-filled syringe 230, in which the needle cover 240 surrounds the proximal end of the needle 233 and the needle 233 does not extend through the aperture 243 of the needle cover 240, as previously explained in relation to FIG. 2.

[0197] To assist with later coupling of the cartridge 200 to the reusable injector device 100, FIG. 3 shows the cartridge 200 comprising a cartridge coupling feature 700 for coupling to an injector coupling feature 720 of the reusable injector device 100. FIG. 3 shows the cartridge coupling feature 700 comprising a recess 710 formed in the inner surface of the cassette outer housing 210, near the proximal end of the cassette outer housing 210. FIG. 3 shows the injector coupling feature 720 comprising an interlock arm 722, which may engage the recess 710 formed in the inner surface of the cassette outer housing 210 to couple the cartridge 200 with the reusable injector device 100. The medicament delivery system 10 shown in FIG. 3 has two interlock arms 722, one located each side of the plunger rod 170, and each arranged to engage a corresponding recess 710 formed in the cassette outer housing 210, however the second interlock arm 722 and second recess 710 are not visible in the cutaway view of FIG. 3. FIG. 3 also shows the plunger rod 170 having a recess 730 formed in its outer circumferential surface at a proximal end, and a resilient element 727 for supporting and biasing the interlock arm 720. Operation of the interlock arm 722, recess 730 and resilient element 727 will be described later in more detail.

[0198] Prior to attachment of the cartridge 200 to the reusable injector device 100, the needle cover 240 may be held in this initial extended position by a needle cover locking mechanism 250, as described previously. The needle cover locking 250 mechanism inhibits axial translation of the needle cover 240 relative to the cassette outer housing 210 and the pre-filled syringe 230 when the needle cover 240 is in its initial position shown in FIG. 3 and the cartridge 200 is not yet coupled to the reusable injector device 100. The needle cover locking mechanism 250 also inhibits rotational movement of the needle cover 240 relative to the cassette outer housing 210 and the pre-filled syringe 230 about the longitudinal axis of the cartridge 200.

[0199] The needle cover locking mechanism 250 is configured to engage with the unlocking element 350 provided in the reusable injector device 100 when the cartridge 200 is coupled to the reusable injector device 100 to allow for rotation of the needle cover 240. In other words, rotation of the needle cover is no longer be inhibited by the needle cover locking mechanism 250 when the cartridge 200 is coupled to the reusable injector device 100 and the needle cover locking mechanism 250 is engaged with the unlocking element 350, as described later in relation to FIG. 5.

[0200] FIGS. 4A-C show the needle cover locking mechanism 250 of FIG. 3 in more detail, from three different angles. The needle cover locking mechanism 250 comprises a clip 251 and first to third cutouts 501 , 502, 503 formed at a distal end of the needle cover 240. The clip 251 is formed on an internal surface of the cassette outer housing 210, extending from the internal surface of the cassette outer housing 210 in an inward radial direction.

[0201] The third cutout 503 extends from the inner to outer surface of the needle cover 240 so that the clip 251 can pass through the third cutout 503. The first cutout 501 and the second cutout 502 are also shown as extending fully through the needle cover 240 from its inner to outer surface, however it should be noted in some circumstances that at least one of the first cutout 501 and the second cutout 502 may instead be formed as a recess in the inner surface of the needle cover, without extending fully through the needle cover 240.

[0202] The clip 251 is arranged at the distal end of the cassette outer housing 210. The clip 251 comprises a first portion 252 that extends from the inner surface of the cassette outer housing 210 in a direction substantially normal to the inner surface of the cassette outer housing 210 and towards the longitudinal axis of the cartridge 200. The clip 251 further comprises a second portion 253 coupled to the first portion 252 that extends substantially parallel to the longitudinal axis of the cartridge 200, in a distal direction from the first portion 252, substantially parallel to the longitudinal axis of the cartridge 200. The second portion 253 is arranged to extend from the first portion 252 so that a portion of the needle cover 240 is accommodated between the second portion 253 and the inner surface of the cassette outer housing 210, as shown in FIG. 3 and FIGS. 4A-C. The second portion 251 may have an arm-like form. The second portion 253 of the clip 251 terminates at its distal end in a retaining block 254, which extends towards the inner surface of the cassette outer housing 210 in a radial direction away from the axis of the cartridge 200. The retaining block 254 comprises a square proximal surface 255 and a ramped distal surface 256. The square proximal surface 255 is located in a space between the second portion 252 and the inner surface of the cassette outer housing 210. The ramped distal surface 256 faces towards the inner surface of the cassette outer housing 210, away from the axis of the cartridge 200.

[0203] The first cutout 501 and the second cutout 502 are generally rectangular in shape and are located adjacent to each other at the distal end of the needle cover 240. The first cutout 501 and the second cutout 502 are arranged circumferentially around the inner surface of the needle cover 240 such that a rotation of the needle cover 240 from its initial position to its primed position about the axis of the cartridge would cause the second cutout 502 to move into a position previously occupied by the first cutout 501 prior to the rotation. The first cutout and the second cutout are separated by a crossbar 505 extending from a proximal to distal direction.

[0204] The third cutout 503 is generally ‘L-shaped’ and is located proximal in the needle cover 240 compared to the first cutout 501 and the second cutout 502, nearer the proximal end of the needle cover 240.

[0205] When the needle cover 240 is in its initial position shown in FIG. 3 and FIGS. 4A-C, rotation of the needle cover 240 is inhibited by the retaining block 504 being received in the first cutout 501. As shown in FIGS. 4A-C, the retaining block 254 is dimensioned to be of a similar cross-sectional shape as the first cutout 501 , such that the lateral sides of the retaining block 254 are in abutment with, or near abutment with, the lateral walls of the first cutout 501. Rotation of the needle cover 240 in one direction (i.e. anti-clockwise when viewing the cartridge 200 of FIG. 3 in a proximal to distal direction along its longitudinal axis) is therefore inhibited by engagement between the retaining block 254 and the crossbar 505, while rotation of the needle cover 240 in the opposite (i.e. clockwise) direction is inhibited by engagement between the retaining block 254 and the lateral wall of the first cutout 501 that is opposite the crossbar 505. It can be seen that rotation of the needle cover 240 may also be inhibited by engagement between the first potion 252 of the clip 251 and a lateral wall of the third cutout 503.

[0206] The clip 251 is able to resiliently deform such that the retaining block 504 can be removed from the first cutout 501 by pivoting the second portion 253 about the first portion 252, in a direction away from the first cutout 501 and towards the axis of the cartridge 200. However, the clip 251 is biased to pivot the retaining block 504 away from the axis of the cartridge, towards the cassette outer housing 210 and into the first cutout 501.

[0207] The cap 260 (mostly hidden in FIG. 3 for visual clarity) comprises a blocking element 266 that projects radially inwards from the inner surface of the tubular wall 261 of the cap 260, for example the distal portion 264 of the tubular wall 261 , towards the axis of the cartridge 200. The blocking element 266 is used for causing the needle cover 240 to rotate about the axis of the cartridge 200. The cap 260 may be coupled to the cassette outer housing 210 such that removal of the cap 260 from the cassette outer housing 210 requires rotation of the needle cover 240 from its initial position to its primed position using the blocking element 266.

[0208] In the state illustrated in FIG. 3, the blocking element 266 of the cap 260 abuts a portion of the needle cover 240 such as the side surface 244 of the needle cover 240 when the needle cover 240 is in its initial position. Since the needle cover 240 is inhibited from rotating due to the needle cover locking mechanism 250, the blocking element 266 is prevented by abutment with the needle cover 240 from moving circumferentially around the axis of the cartridge 200 to rotate the needle cover 240. As a result, rotation of the cap 260 is also inhibited by the needle cover 240. To allow the needle cover locking mechanism 250 to release the needle cover 240 for rotation and therefore allow the cap 260 to be rotated and removed, the cartridge 200 must be coupled to the reusable injector device 100 as later described in relation to FIG. 5. The needle cover locking mechanism 250 therefore prevents removal of the cap 260 from the remainder of the cartridge 200 until the cartridge 200 has been coupled to the reusable injector device 100, improving safety of the cartridge 200.

[0209] FIG. 3 further shows the needle cover return lock 310 comprising a needle cover locking arm 610 that extends in a substantially proximal direction from the needle cover 240. The needle cover locking arm 610 is pivotably coupled to the needle cover 240 at its distal end and is biased to pivot away from being substantially parallel to the axis of the cartridge, in a direction towards the cassette outer housing 210. The needle cover return lock 310 further comprises a cassette arm 615 extending from the inner surface of the cassette outer housing 210 into the internal bore 213. The cassette arm 615 extends perpendicular to the longitudinal axis of the cassette 200 and substantially perpendicular to the needle cover locking arm 610. The needle cover 240 further comprises a fourth cutout 616 through which the cassette arm 615 can extend as the needle cover 240 rotates and axially translates. The needle cover locking arm 610 may also extend through the fourth cutout 616.

[0210] As shown in FIG. 3, a locking element 612 is formed at the distal end of the needle cover locking arm 610. The locking element 612 is arranged such that it is biased into engagement with an upper surface of the cassette arm 615 when the needle cover 240 is in its initial position shown in FIG. 3, the upper surface being the surface of the cassette arm 615 facing the axis of the cartridge 200. The engagement of the needle cover locking arm 610 with the cassette arm 615 inhibits the needle cover locking arm 310 from pivoting away from the axis of the cartridge 200 and further towards the inner surface of the cassette outer housing 210. The cassette arm 615 may also assist with inhibiting axial translation of the needle cover 240 by abutting one or more side walls of the fourth cutout 616, as shown in FIG. 3.

[0211] FIG. 5 shows the cartridge 200 of FIG. 3 once attached to the reusable injector device 100. Again, the pre-filled syringe 230 and the majority of the cap 260 are not shown for visual clarity.

[0212] A user has pushed the distal end of the cartridge 200 into the proximal end of the reusable injector device 100 so that the cartridge 200 and reusable injector device 100 become coupled. The cartridge 200 and reusable injector device 100 may be coupled by any suitable coupling feature, for example by a friction fit, one or more clips, corresponding ridges and grooves, a bayonet coupling, a threaded coupling, a push fit, or the like. Example coupling features are described later in relation to FIGS. 35A-C, FIG. 36 and FIG. 37 for example.

[0213] FIG. 5 shows the unlocking element 350 for unlocking the needle cover locking mechanism 250 when the cartridge 200 is coupled to the reusable injector device 100. The unlocking element 350 projects proximally from the reusable injector device 100, towards the cartridge 200.

[0214] The unlocking element 350 is arranged such that it is brought into abutment with the needle cover locking mechanism 250 when the cartridge 200 is coupled to the reusable injector device 100. For this purpose, the unlocking element 350 may be located adjacent the tubular wall 11 of the reusable injector device 100, with a gap between the unlocking element 350 and tubular wall 11 sufficient to accommodate the cassette outer housing 210 and the annular wall 122 of the needle cover shuttle 120. FIG. 5 shows the unlocking element 350 projecting from the proximal surface 173 of the plunger rod guide sleeve 171, however any suitable location may be chosen where it allows the unlocking element 350 to engage with the needle cover locking mechanism 250 when the cartridge 200 and reusable injector device 100 are coupled.

[0215] As the cartridge 200 is brought into contact with the reusable injector device 100 during coupling, the unlocking element 350 engages with the needle cover locking mechanism 250 to unlock the needle cover locking mechanism 250 and allow for rotation of the needle cover 240. Where the needle cover locking mechanism 250 comprises a clip 251 as previously described, the unlocking element 350 engages with the clip 251 to lift the clip 251 out of the first cutout 501 in the needle cover 240. By lifting the clip 251 out of the first cutout 501 , the needle cover 240 is now free to rotate about the axis of the cartridge 200 from its initial position to its primed position.

[0216] FIGS. 6A-C and FIGS. 7A-B show the unlocking element 350 and its interaction with the clip 251 in more detail.

[0217] FIG. 6A is a magnified view of the unlocking element 350 and the clip 251 shown in FIG. 5. FIG. 6A shows the unlocking element 350 projecting in a proximal direction from the reusable injector device 100 and having a proximal ramped surface 352 formed at its proximal end. The ramped surface 352 of the unlocking projection 350 faces towards the axis of the cartridge 200 when the cartridge 200 is coupled to the reusable injector device 100. The ramped surface 352 of the unlocking projection 350 is configured to abut the ramped distal surface 256 of the clip 251 as the cartridge 200 is coupled to the reusable injector device 100.

[0218] FIG. 7A is a schematic side view of a portion of the cartridge 200 and reusable injector device 100 of FIG. 5, as the cartridge 200 is being coupled to the reusable injector device 100. FIG. 7A shows the first portion 252 of the clip 251 extending through the third cutout 503 in the needle cover 240. The second portion 253 of the clip 251 extends axially towards, and in alignment with, the unlocking element 350 of the reusable injector device 100. The retaining block 254 extends into the first cutout 501 in the needle cover 240, with the square proximal surface 255 abutting the proximal wall of the first cutout 501 and therefore inhibiting axial movement of the needle cover 240 in the distal to proximal direction relative to the cassette outer housing 210. The ramped surface 352 of the unlocking projection 350 and the ramped distal surface 256 of the clip 251 are aligned along the same axis parallel to the axis of the cartridge 200 but have not yet engaged.

[0219] As the cartridge 200 is moved by the user towards the reusable injector device 100, the gap between the ramped surface 352 of the unlocking projection 350 and the ramped distal surface 256 of the clip 251 becomes smaller until the ramped surface 352 of the unlocking projection 350 and the ramped distal surface 256 of the clip 251 engage. Due to interaction between the ramped surface 352 of the unlocking projection 350 and the ramped distal surface 256 of the clip 251 as they slide towards and across one another, further axial movement of the cartridge 200 towards the reusable injector device 100 is converted into radial movement of the second portion 253 of the clip 251 away from the inner surface of the cassette outer housing 210 and towards the axis of the cartridge 200, lifting the retaining block 254 out of the first cutout 501 until the square proximal surface 255 is no longer in abutment with the proximal wall of the first cutout 501 , as shown in FIG. 7B, and therefore rotation of the needle cover 240 is no longer inhibited. The motion of the second portion 253 of the clip 251 is a pivoting motion about the first portion 252 of the clip 251, caused by a resilient coupling between the first portion 252 and the second portion 253.

[0220] The unlocking element 350 may be formed from a material having a lesser resilience (greater rigidity) than the clip 251 so as to reduce radial deflection of the unlocking element 350 as the cartridge 200 is coupled to the reusable injector device 100.

[0221] In FIG. 7B, the distal end surface of the cassette outer housing 210 is now in abutment with a proximal surface of the housing 110 of the reusable injector device 100, inhibiting further movement of the cassette outer housing 210 towards the reusable injector device 100. The cartridge 200 and reusable injector device 100 are now fully coupled.

[0222] FIGS. 6B and 6C show the interaction between the clip 251 and the unlocking element 350 of FIG. 6A from alternative viewing angles.

[0223] It should be noted that the lifting of the clip 251 out of the first cutout 501 by the unlocking element 350 may in some examples only require a relatively small movement of the clip 251.

[0224] As should be evident from FIG. 5, FIGS. 6A-C and FIGS. 7A-B, axial movement of the needle cover 240 in a proximal to distal direction remains inhibited due to the engagement between the clip 251 and the third cutout 503. More specifically, axial movement of the needle cover 240 in a proximal to distal direction relative to the cassette outer housing 110 remains inhibited due to abutment between a first proximal wall of the third cutout 503 and a proximal surface of the first portion 252 of the clip 251. The needle cover locking arm 610 also remains engaged with the upper surface of the cassette arm, 615 inhibiting pivoting of the needle cover locking arm 610 towards the cassette outer housing 210. While the cartridge 200 is coupled to the reusable injector device 100, the distal end surface of the needle cover 240 engages with the proximal end surface of the annular wall 122 of the needle cover shuttle 120. The needle cover shuttle spring 121 applies a biasing force to the needle cover shuttle 120 in the proximal direction such that the needle cover shuttle 120 in turn makes contact with, and applies a force to, the distal end surface of the needle cover 240, ensuring the needle cover 240 is biased in the proximal direction.

[0225] FIG. 8 shows a cross-sectional side view of the cartridge 200 and reusable injector device 100 of FIG. 5. FIG. 8 shows the presence of an additional clip 25T that can perform the same function as the original clip 251. FIG. 8 also shows a locking recess 617 formed in the inner surface of the cassette outer housing 210, at a distal end of the cassette outer housing 210. As shown in FIG. 8, the locking recess 617 may take the form of an aperture extending from the inner surface to outer surface of the cassette outer housing 210. The locking recess 617 is located adjacent the cassette arm 615 and is configured to retain the locking element 612 of the needle cover locking arm 610 to inhibit axial translation of the needle cover 240 after the needle cover 240 has moved into its post-dose delivery position. However, when the needle cover 240 is in its initial or primed position, the locking element 612 is disengaged from the locking recess 617 due to engagement of the needle cover locking arm 610 with the cassette arm 615. The function of the locking recess 617 will be described later in more detail.

[0226] FIG. 9 shows the cartridge 200 and reusable injector device 100 of FIG. 5 during a subsequent cap removal step, in which the needle cover 240 is rotated from its initial position to its primed position. The clip 251 has been lifted by the unlocking element 350 as previously described in relation to FIG. 5 and therefore the needle cover 240 is now free to rotate about the axis of the cartridge 200. FIG. 9 shows the cartridge 200 after this rotation of the needle cover 240 has taken place.

[0227] In the embodiment of FIG. 9, the cap 260 must first be rotated with respect to the cassette outer housing 210 about the axis Xs-Xs before being axially removed from the cassette outer housing 210. FIG. 9 shows the cap 260 after being rotated but not axially removed.

[0228] The needle cover 240 may be rotated by a user gripping and rotating the cap 260 about the axis of the cartridge 200. As the cap 200 is rotated, the blocking element 266 of the cap 260 is brought into abutment with, and applies a force to, the side surface 244 of the needle cover 240. Since the clip 251 is no longer held in the first cutout 501, the force applied by the blocking element 266 causes the needle cover 240 to rotate about the axis of the cartridge 200 in unison with the blocking element 266 and cap 260. Rotation of the needle cover 240 is guided by the first portion 252 of the clip 251 traversing through the third cutout 503 in a channel between the distal wall of the third cutout 503 and the first proximal wall of the third cutout 503.

[0229] Rotation of the cap 260 and the needle cover 240 may continue until the first portion 252 of the clip 251 is brought into abutment with a side wall of the third cutout 503, at which stage the first portion 252 of the clip 251 is now in alignment with a portion of the third cutout 503 having second proximal wall further in the proximal direction than the first proximal wall of the third cutout 503. The second cutout 502 of the needle cover 240 will now be located between the retaining block 254 of the clip 251 and the inner surface of the cassette outer body 210, however the clip 251 remains distended away from the second cutout 502 by continued engagement with the unlocking element 350.

[0230] The cap 260 may then be removed from the remainder of the cartridge 200 by pulling the cap 200 in a distal to proximal direction.

[0231] FIGS. 10A-H are used to illustrate removal of the cap 260 from the cassette outer housing 210 in greater detail, in accordance with embodiments of the present disclosure.

[0232] The cap 260 comprises a guide pin 267 that projects radially outwards from the outer surface of the tubular wall 261 of the cap 260, for example from the distal portion 264 of the tubular wall 261. As shown in FIG. 10A, the guide pin 267 is arranged to be received in a track 270 formed at the inner surface of the cassette outer housing 210, at a proximal end of the cassette outer housing 210. The track 270 is configured to guide the guide pin 267 along the track 270, and may comprise a groove formed in the inner surface of the cassette outer housing 210. The track 270 may be L-shaped, having a first track portion 271 extending circumferentially around the inner surface of the cassette outer housing 210, perpendicular to the longitudinal axis of the cartridge 200. FIG. 10B shows the same cartridge 200 as FIG. 10A, but viewed from the opposite side of the cartridge 200 to show the position of the needle sleeve 240. The cartridge 200 shown in FIG. 10A and FIG. 10B may correspond to the cartridge shown in FIG. 5, that is, before the cap 260 has been rotated and the needle sleeve 240 is in its initial position. FIG. 10A shows the guide pin 267 received within the first track portion 271 while FIG. 10B shows the blocking element 266 of the cap in abutment with the side surface 244 of the needle cover 240. The cap 260 cannot be axially removed from the cassette outer housing 210 due to the presence of the guide pin 267 in the first track portion. The cap 260 must first be rotated then axially translated to remove it from the cassette outer housing 210. When the guide pin 267 is received in the first track portion 271, a rotation of the cap 260 by a user about the axis of the cartridge 200 relative to the cassette outer housing 210 will cause the guide pin 267 to traverse the first portion 271 of the track 270 until it abuts a terminal wall of the first portion 271 , preventing further rotation of the cap 260. This rotational movement of the cap 260 along the first track portion 271 is shown in FIG. 10C and is used to rotate the needle sleeve 240 from its initial position to its primed position. FIG. 10D is a view of the cartridge 200 shown in FIG. 10C from the opposite side of the cartridge 200 to show the position of the needle sleeve 240 now in its primed position, having been rotated by the blocking element 266.

[0233] When the guide pin 267 abuts the terminal wall of the first track portion 271, it will now be aligned with a second track portion 272, which extends axially in a proximal direction along the inner surface of the cassette outer housing 210 to the proximal end of the cassette outer housing 210, at which point the second track portion 272 has an open end. Therefore, once the guide pin 267 is aligned with the second track portion 272, the user may pull the cap 260 in a distal to proximal axial direction relative to the cassette outer housing 210 as shown in FIG. 10E, causing the guide pin 267 to traverse the second portion 272 of the track 270 in the same axial direction until the guide pin 267 passes through the open end of the second portion 272 of the track 270. FIG. 10F is a view of the cartridge 200 shown in FIG. 10E from the opposite side of the cartridge 200 to show that the needle sleeve 240 remains in its primed position, but the blocking element 266 is no longer visible, having been proximally removed from within the cassette outer housing 210. At this stage, the cap 260 may now be fully uncoupled from the cassette outer housing 210 and can be fully removed, as illustrated in FIG. 10G.

[0234] FIG. 10H shows the needle cover 2440 comprising an optional detent 275 formed on its outer surface to inhibit recoupling of the cap 260 to the cassette outer housing 210 once the cap 260 has been removed. The detent 275 may be located on the tubular wall 241 of the needle cover 240, adjacent the distal end of the cassette outer housing 210. The detent 275 may comprise a distal ramped surface 276 and a proximal square surface 277, arranged such that the blocking projection 266 of the cap 260 can pass over the ramped surface 276 as the cap 260 is removed from the cassette outer housing 210, however replacement of the cap 260 will be inhibited by engagement between the blocking projection 266 and the square surface 277. In alternative embodiments, the detent 275 may instead be formed on the inner surface of the cassette outer housing 210. Once the needle cover 240 has been rotated into its primed position shown in FIG. 9, a rotational stop element 280 may inhibit the needle cover 240 from rotating back in the opposite direction, out of the primed position towards the initial position. The rotational stop element 280 may be arranged such that it is brought into non-returnable abutment with a feature of the needle cover 240 once the needle cover 240 has been rotated to its primed position. As an example illustrated in FIG. 9, the rotational stop element 280 may comprise an arm 281 extending from the inner surface of the cassette outer housing 210 perpendicular to the longitudinal axis of the cartridge 200, the arm 281 having a stop projection 282 configured to engage with the side surface 244 of the needle sleeve 240 once the needle sleeve 240 has been rotated to its primed position. The arm 281 may be biased to pivot towards the needle cover 240. The biasing may be provided by the arm

[0235] 281 being formed from a resilient material.

[0236] When the needle sleeve 240 is in its initial position as shown in FIG. 5, the stop projection

[0237] 282 may be in abutment with the outer surface of the needle sleeve 240, causing the arm

[0238] 281 to be deflected radially away from the needle sleeve 240. As the needle sleeve 240 is rotated from its initial position shown in FIG. 5 to its primed position shown in FIG. 9, the stop projection 282 of the arm 281 moves across the outer surface of the needle sleeve 240 until it passes over an edge of the needle sleeve 240, at which point the stop projection 282 is no longer in abutment with the outer surface of the needle sleeve 240. Due to the biasing of the arm 281 and the lack of engagement between the stop projection

[0239] 282 and the outer surface of the needle sleeve 240, the arm 281 pivots into the internal bore 213 of the cartridge 200, towards the longitudinal axis of the cartridge 200. The arm 281 is arranged such that the stop projection 282 now abuts, or is close to abutment with, the side surface of the needle cover 240 when the needle cover 240 is in its primed position. The abutment between the stopping projection 282 and the side surface of the needle cover inhibits rotation of the needle cover 240 back from its primed position towards its initial position.

[0240] As the needle cover 240 is rotated from its initial position to its primed position, the needle cover locking arm 610 moves along the upper surface of the cassette arm 615, remaining in engagement with the cassette arm 615 due to the biasing of the needle cover locking arm 610. FIG. 11A shows the needle cover locking arm 610 and cassette arm 615 of FIG. 9 in greater detail, showing that the locking element 612 of the needle cover locking arm 610 has translated across the upper surface of the cassette arm 615 toward an opposite end of the cassette arm 615. However, the locking element 612 remains disengaged from the locking recess 617 located below due to the presence of the cassette arm 615 therebetween. Due to the increasing distance between the upper surface of the cassette arm 615 and the inner surface of the cassette outer housing 210, the needle cover locking arm 610 has been distended towards the axis of the cartridge 200 as the needle cover 240 has been rotated.

[0241] FIG. 11 B and FIG. 11C show the clip 251 and unlocking extension 350 of FIG. 9 in closer detail, from alternative angles. The clip 251 remains lifted out of the second cutout 502 by continued engagement with the unlocking element 350.

[0242] FIG. 12 shows the cartridge and reusable injector device of FIG. 9 during a subsequent state to the state of FIG. 9. The pre-filled syringe 230 is hidden for clarity.

[0243] A user has placed the end wall 242 of the needle cover 240 on an injection site and moved the reusable injector device 100 in a distal to proximal direction towards the injection site, causing the needle cover 240 to translate axially into the cassette outer housing 210 in a proximal to distal direction along the axis of the cartridge, and thereby allowing the proximal end of the needle (not shown) to extend through the aperture of the needle cover and penetrate the injection site. As the user has pushed the needle cover 240 from its primed position shown in FIG. 9 to its dose delivery position shown in FIG. 12, the distal end of the needle cover 240 has engaged and axially moved the needle cover shuttle 120 in a distal direction, further into the housing 110 of the reusable injector device 100 and further tensioning the needle cover shuttle spring 121. FIG. 12 shows the distal end of the needle cover 240 has translated further into the housing 110 of the reusable injector device 100, such that it has passed into the annular cavity 172.

[0244] As the needle cover 240 moves axially towards the reusable injector device 100 from its primed position to its dose delivery position, the needle cover locking arm 610 slides distally across the upper surface of the cassette arm 615 until it disengages with the cassette arm 615, at which point the biasing force of the needle cover locking arm 610 and the lack of engagement between the needle cover locking arm 610 and the cassette arm 615 causes the needle cover locking arm 610 to pivot away from the axis of the cartridge and towards the inner surface of the cassette outer housing 210 until the engagement element 612 engages with the inner surface of the cassette outer housing 210. The relative arrangement of the cassette arm 615, the needle cover locking arm 610 and the locking recess 617 is such that the locking element 612 of the needle cover locking arm 610 does not engage the locking recess 617 during translation of the needle cover 240 from its primed position to its dose delivery position. Continued axial movement of the needle cover 240 in a distal direction results in the locking element 612 of the needle cover locking arm 610 sliding across the inner surface of the cassette outer housing 210 in the distal direction, with further pivoting of the needle cover locking arm 610 inhibited due to abutment with the inner surface of the cassette outer housing 610.

[0245] FIG. 12 shows the rotational stop element 280 remains engaged with the side surface 244 of the needle cover 240, inhibiting rotation of the needle cover 240 as it moves from its primed to dose delivery positions. Engagement between the clip 251 and lateral walls third cutout 503 may also inhibit rotation of the needle cover 240 as it moves from its primed to dose delivery positions.

[0246] Once the needle cover 240 has reached its dose delivery position, further distal axial movement of the needle cover 240 relative to the cassette outer housing may be inhibited. This inhibition may be provided by one or more of an engagement between the clip 251 and a proximal wall of the third cutout 503, engagement between the cassette arm 615 and a proximal wall of the fourth cutout 616, engagement between the distal end of the needle cover 240 and a feature within the annular cavity 172, engagement between a distal side of the needle cover shuttle 120 and a feature within the annular cavity 172, or any other suitable mechanism.

[0247] FIG. 13A is a cross-sectional side view of the medicament delivery system 10 of FIG. 12. FIG. 13B is an enlarged view of the needle cover return lock 310 shown in FIG. 13A, where it can be seen that the needle cover locking arm 610 is no longer engaged with the cassette arm 615 and instead abuts the inner surface of the cassette outer housing 210.

[0248] FIG. 14 shows an enlarged view of the cassette arm 615 and a portion of the needle cover 240 of the medicament delivery system 10 of FIG. 12, showing that the needle cover locking arm 610 no longer rests on the upper surface of the cassette arm 615. The locking recess 617 is visible below the cassette arm 615.

[0249] FIG. 15 shows a magnified front view of the interlock arm 722 of the medicament delivery system 10 of FIG. 12. FIG. 15 shows the interlock arm 722 having an arm-like form and being movable in opposing radial directions from the longitudinal axis Xs-Xs, both away from and towards the plunger rod 170, through a guide channel 780 formed in the proximal surface 173 of the plunger rod guide sleeve 171. The needle cover shuttle 120 shown in FIG. 15 has a cutout 125 formed in the proximal surface of its annular wall 122 to accommodate the interlock arm 722.

[0250] An outer end 724 of the interlock arm 722 that is furthest from the plunger rod 722 is partially received within the recess 710 of the cassette outer housing 210, thereby coupling the cartridge 200 to the reusable injector device 100. An inner end 738 of the interlock arm 722 that is nearer to the plunger rod 170 than the outer end 724 is partially received in the recess 730 of the plunger rod 170. A resilient element 727 biases the interlock arm 722 into a neutral radial position shown in FIG. 15, in which the interlock arm 722 is free to move radially further towards the plunger rod 170 in a first direction and is free to move radially further away from the plunger rod 170 in a second, opposite direction, but is biased to return to the neutral position. In view of the outer end 724 of the interlock arm 722 being only partially received within the recess 710 of the cassette outer housing 210, the coupling between the cartridge 200 and the reusable injector device 100 is relatively weak and can be overcome by applying a relatively small axial force to the cartridge 200 in the proximal direction, pulling the cassette outer housing 210 away from the reusable injector device 100. In doing so, the interlock arm 722 can be moved slightly in the radial direction towards the plunger rod 170, with the outer end 724 of the interlock arm 722 disengaging from the recess 710 of the cassette outer housing 210 and the inner end 738 of the interlock arm 722 moving further into the recess of the plunger rod 170, therefore releasing the cartridge 200 from the reusable injector device 100. To instead couple the cartridge 200 to the reusable injector device 100, the distal end of the cassette outer housing 210 is axially pushed into the annular gap between the tubular wall 11 and the needle cover shuttle 120 until its distal end contacts the interlock arm 722, at which point continued distal axial movement of the cassette outer housing 210 towards the reusable injector device 100 will push the interlock arm 722 slightly in the radial direction towards the plunger rod 170 such that the inner end 738 of the interlock arm 722 moves further into the recess of the plunger rod 170 and the distal end of the cassette outer housing 210 can pass the outer end 724 of the interlock arm 722. Eventually the recess 710 of the cassette outer housing 210 will become aligned with the outer end 724 of the interlock arm 722, at which point the biasing force of the resilient element will cause the interlock arm 722 to translate radially away from the plunger rod 170, until the outer end 724 of the interlock arm 722 partially engages the recess of the cassette outer housing 210, coupling the cartridge 200 to the reusable injector device 100. Returning to FIG. 12, once the needle cover 240 has been moved from its primed position to its dose delivery position, proximal axial movement of the plunger rod 170 by the plunger rod driving mechanism 180 to dispense the medicament may be initiated.

[0251] Initiation of the plunger rod movement may be performed using any suitable mechanism. For example, initiation may be responsive to distal movement of the needle cover 240 and / or needle cover shuttle 120 being detected (i.e. ‘needle cover’ activated dispensing). Initiation of the plunger rod movement may be responsive to the needle cover 240 and / or needle cover shuttle 120 moving at least a threshold distance in the proximal to distal direction, for example a threshold distance between 10 mm and 15 mm, such as 12 mm. Other threshold distances may be used instead. Threshold movement of the needle cover 240 and / or needle cover shuttle 120 may be detected mechanically or using any suitable sensor. Upon detection of the threshold movement, movement of the plunger rod 170 may be initiated by the plunger rod driving mechanism 180.

[0252] FIG. 16 shows the cartridge 200 and reusable injector device 100 of FIG. 12 at an ‘end of dose delivery’ stage, after the plunger rod 170 has been axially translated in the proximal direction into the pre-filled syringe 230 so as to proximally move the plunger 235 and dispense a dose of medicament. It can be seen that the recess 730 of the plunger rod 170 is no longer aligned with the inner end 728 of the interlock arm 722. The needle cover 240 remains pressed against the injection site and therefore the needle cover 240 remains in its dose delivery position.

[0253] FIG. 17 provides an alternative side view of the cartridge 200 and reusable injector device 100 shown in FIG. 16, however the pre-filled syringe 230 is now visible. It can be seen that the piston 235 has been moved proximally along the longitudinal axis Xs-Xs of the medicament delivery system 10 by the proximal translation of the plunger rod 170. FIG. 17 shows the plunger rod 170 having a piston engagement projection 177 projecting proximally from its proximal end, wherein the piston engagement projection 177 engaged with a piston recess 236 formed in the distal surface of the piston 230 to drive the piston 230.

[0254] The needle cover 240 has been retracted within the cassette outer housing 210 into its dose delivery position, allowing the needle 233 to extend outside the proximal end of the needle cover 240 to penetrate the injection site. FIG. 18 shows an enlarged view of the cassette arm 615 and a portion of the needle cover 240 of the cartridge 200 and reusable injector device 100 shown in FIG. 16, showing that the locking element 612 is still not received in the locking recess 617.

[0255] FIG. 19 shows an enlarged view of the interlock arm 722 of the medicament delivery system 10 of FIG. 16. As the plunger rod 170 was proximally translated to deliver a dose of medicament, the recess 730 formed in the outer circumferential surface of the plunger rod 170 was moved out of alignment with the inner end 728 of the interlock arm 722. Since the inner end 728 of the interlock arm 722 was only partially engaged with the recess and the interlock arm 722 is free to radially translate, translation of the plunger rod 170 in the proximal direction caused the inner end 728 of the interlock arm 722 to be disengaged from the recess by moving the interlock arm 722 in a radial direction away from the plunger rod 170. This movement in turn caused the outer end 724 of the interlock arm 722 to move further into engagement with the recess 710 of the cassette outer housing 210, as shown in FIG. 19. The cartridge 200 is therefore now strongly coupled to the reusable injector device 100. So long as the plunger rod 170 remains extended in its proximal position with the recess 730 not aligned with the inner end 728 of the interlock arm 722, the inner end 728 of the interlock arm 722 is unable to return to being received in the recess 730 of the plunger rod 170 and so the outer end 724 of the interlock arm 722 remains in deep engagement with the recess 710 of the cassette outer housing 210.

[0256] Uncoupling of the cartridge 200 from the reusable injector device 100 is therefore inhibited during medicament delivery.

[0257] FIG. 20 shows the cartridge 200 and reusable injector device 100 of FIG. 16 during a subsequent step, once the reusable injector device 100 and needle cover 240 have been removed from the injection site after dose delivery. The proximal end of the needle cover 240 is no longer being held against the injection site and therefore the biasing force provided by the needle cover shuttle 120 and needle cover shuttle spring 121 has caused the needle cover 240 to translate back out of the cassette outer housing 210 from its dose delivery position shown in FIG. 16 to its post-dose delivery position shown in FIG. 20, in a distal to proximal direction along the longitudinal axis of the cartridge 200. In the postdose delivery position, the needle cover 240 completely covers the proximal end of the needle 233 (hidden in FIG. 20) so that the needle 233 does not extend through the aperture 243 in the needle cover 240. It can be seen that the post-dose delivery position of the needle cover 240 relative to the cassette outer housing 210 is substantially identical to the primed position of the needle cover 210 shown in FIG. 9. The needle shuttle 120 has returned to its initial proximal position within the reusable injector device 100.

[0258] As the needle cover 240 axially translates in the proximal direction from its dose delivery position to its post-dose delivery position, the locking element 612 of the needle cover locking arm 610 translated in a proximal direction along the inner surface of the cassette outer housing 210. Since the locking element 612 of the needle cover locking arm 610 previously disengaged from the upper surface of the cassette arm 615 and pivoted towards the cassette outer housing 210 during the movement of the needle cover from its primed position to its dose delivery position, the needle cover locking arm 610 now slides under the cassette arm 615, between the cassette arm 615 and the inner surface of the cassette outer housing 210, as the needle cover 240 moves from its dose delivery position to its post-dose delivery position. Once the needle cover 240 is in its post-dose delivery position, the locking element 612 of the needle cover engages with the locking recess 617 formed in the cassette outer housing 610 to prevent axial movement of the needle cover back in the proximal to distal direction (and optionally also in the distal to proximal direction). FIG. 21 shows the needle cover locking arm 610 located between the cassette arm 615 and the inner surface of the cassette outer housing 210, with the locking element 612 engaged with the locking recess 617.

[0259] FIG. 21 shows an alternative side view of the cartridge 200 and reusable injector device 100 shown in FIG. 20, however the pre-filled syringe 230 is now visible. The needle cover 240 has translated to its post-dose delivery position and so that the needle 233 no longer extends beyond the proximal end of the needle cover 240. FIG. 21 also shows engagement of the locking element 612 with the locking recess 617.

[0260] FIG. 22 shows an enlarged side view of a portion of the medicament delivery system of FIG. 21, showing positions of the needle sleeve locking arm 610 and cassette arm 615, with engagement between the locking element 612 and the locking recess 617.

[0261] FIG. 23 shows an enlarged view of the needle cover return lock 310 shown in FIG. 20, showing how the needle cover locking arm 610 has translated along the inner surface of the cassette outer housing 210, under the cassette arm 615, until the locking element 612 has aligned with the locking recess 617, at which point the needle cover locking arm 610 has pivoted further towards the cassette outer housing 210 to engage the locking element 612 with the locking recess 617. The resilient biasing of the needle cover locking arm 610 towards the cassette outer housing 210 can assist in inhibiting removal of the locking element 612 from the locking recess 617, thereby inhibiting axial translation of the needle cover 240.

[0262] FIG. 24 shows an enlarged view of the interlock arm of FIG. 20 engaging with the plunger rod 170 and the cassette outer housing 210. The plunger rod 170 has not yet translated back in a distal direction and so the interlock arm 722 remains strongly engaged with the recess 710 of the cassette outer housing, inhibiting uncoupling of the cartridge 200 from the reusable injector device 100.

[0263] FIG. 25 shows the cartridge and reusable injector device of FIG. 20 during a next step, once the plunger rod 170 has been retracted in the proximal to distal direction, back into the housing 110 of the reusable injector device 100. The plunger rod 170 may be retracted by any suitable mechanism. For example, the plunger rod 170 may be retracted electromechanically, for example using an electromechanical motor, or mechanically, for example using a spring mechanism and / or a user-applied force. Retraction of the plunger rod 170 may be automatic, for example responsive to the dose being delivered, or manually initiated, for example responsive to a user actuating an input button (not shown) or removal of the needle cover 240 from the injection site being detected.

[0264] The cartridge 200 remains strongly coupled to the reusable injector device 100 by the interlock arm 722 as the plunger rod 170 is retracted, until the plunger rod 170 reaches its initial axial position and the interlock arm 722 is once again aligned with the plunger rod recess 730. Once the interlock arm 722 is aligned with the plunger rod recess 730, the interlock arm 722 may translate radially towards the plunger rod 170 due to the biasing force provided by the resilient element 727, until its neutral position is reached. As the interlock arm 722 translates radially towards the plunger rod 722, the outer end 724 of the interlock arm 722 translates out of the recess 710 in the cassette outer housing 210, thereby allowing the cartridge 200 to be separated from the reusable injector device 100.

[0265] FIG. 26 shows an alternative side view of the cartridge 200 and reusable injector device 100 shown in FIG. 25, however the pre-filled syringe 230 is now visible. The plunger rod 170 has translated back to its distal position within the reusable injector device 100. FIG. 26 also shows the presence of an additional needle cover return lock 310’, which is located opposite to the previously-described needle cover return lock 310 and has similar components and function. FIG. 27 shows an enlarged view of the interlock arm of FIG. 25 once again engaging with the recess 730 of the plunger rod 170 and the recess 710 of the cassette outer housing 210. The interlock arm 722 is seen to have returned to its neutral position.

[0266] FIG. 28 shows the cartridge 200 and reusable injector device 100 of FIG. 25 during a next step, once the cartridge has been uncoupled from the reusable injector device 100. The user removes the cartridge 200 by pulling it away from the reusable injector device 100 in a distal to proximal direction, to overcome any frictional or mechanical coupling between the cartridge 200 and reusable injector device 100, for example the coupling provided by the interlock arm 722 and the recess 710 in the cartridge outer housing 210. The separated reusable injector device 100 can now be reused with a new cartridge 200. The used cartridge 200 can now be safely disposed.

[0267] With the cartridge 200 uncoupled from the reusable injector device 100, the needle cover locking mechanism 250 of the cartridge 200 has disengaged from the unlocking element 350 of the reusable injector device 100. As a result, the clip 251 is no longer distended towards the longitudinal axis of the cartridge 200 and pivots back towards the inner surface of the cassette outer housing 210. Since the needle cover 240 has been rotated relative to the cassette outer housing 210 compared to the initial position of the needle cover 240, the retaining block 254 of the clip 251 is now in alignment with the second cutout 502 of the needle cover 240. Therefore, once the clip 251 pivots back towards the inner surface of the cassette outer housing 210, it engages with the second cutout 502 to inhibit axial translation of the needle cover 240 relative to the cassette outer housing 210.

[0268] The needle cover 240 also remains inhibited from being distally translated into the cassette outer housing 210 and exposing the needle 233 by the needle cover return lock 310.

[0269] Rotation of the needle cover 240 relative to the cassette outer housing 210 is inhibited by the rotational stop element 280, engagement of the clip 251 with the second cutout 502, and engagement of the locking element 612 with the locking recess 617.

[0270] FIGS. 29A, 29B, 29C and 29D represent magnified views of the needle cover return lock 310 as previously shown in FIGS. 5, 9, 12 and 20 respectively, illustrating in closer detail the locations of the needle cover locking arm 610, locking element 612, cassette arm 615 and locking recess 617. Alternative implementations of the needle cover return lock 310 for inhibiting axial translation of the needle cover 240 relative to the cassette outer housing 210 are illustrated with respect to FIG. 30, FIGS. 31A-D and FIG. 32.

[0271] FIG. 30 shows a mechanism using a rotatable collar 800 surrounding, and coaxial with, the cassette outer housing 210. A pin 802 projecting from the outer surface of the needle cover 240 is arranged to be received with a track 801 formed in an inner surface of the collar 800. The track 801 and the pin 802 may be arranged such that rotation of the collar 800 about the longitudinal axis of the cassette outer housing 210 by a user causes the pin 802 to traverse the track 801. The track 801 is shaped such that, prior to rotation of the rotatable collar 800, distal translation of the needle cover 240 relative to the cassette outer housing 210 is inhibited due to interaction between the pin 802 and a wall of the track 801. The track 801 is further shaped such that, as the rotatable collar 800 is rotated, the pin 802 traverses the track 801 , allowing the needle cover 240 translate distally relative to the cassette outer housing 210. After the needle cover 240 has moved distally and then proximally relative to the cassette outer housing 210 (i.e. during and after an injection process), continued rotation of the rotatable collar 800 eventually leads to the needle cover 240 being once again prevented from translating distally relative to the cassette outer housing 210, du to an interaction between the pin 802 and the track 801.

[0272] FIGS. 31A-D show an alternative mechanism for preventing axial translation of the needle sleeve 240 using a movable ramp 820. As shown in FIG. 31A, a raised platform 840 is formed on the inner surface of the cassette outer housing 210, with a proximal edge of the platform 840 forming a shoulder 380 with another portion of the cassette outer housing 210. The movable ramp 820 is positioned adjacent the inner surface of the cassette outer housing 210 such that a square surface 822 of the movable ramp 820 abuts the shoulder 830. A portion of the square surface 822 extends beyond the shoulder 830 of the platform 840. A ramped surface 821 of the movable ramp 820 is angled away from the inner surface of the cassette outer housing 210 and in a proximal direction. A needle cover catch 810 forming part of the needle cover 240 extends distally within the cassette outer housing 210, having a ramped surface 811 and a square surface 812. The ramped surface 811 of the needle cover catch 810 abuts the ramped surface 821 of the movable ramp 820. The square surface 812 of the needle cover catch 810 is located proximally adjacent to the ramped surface 811, facing a proximal direction. The needle cover catch 810 is resiliently biased towards the cassette outer housing 210. The positions of the movable ramp 820 and needle cover catch 810 shown in FIG. 31A correspond to the primed position of the needle cover 240 described previously.

[0273] As the needle cover 240 is axially translated in a distal direction from its primed position to its dose delivery position, the needle cover catch 810 also axially translated, as shown in FIG. 31 B. In doing so, the needle cover catch 810 moves distally over the movable ramp 820, with the ramped surface 811 of the needle cover catch 810 sliding over the ramped surface 821 of the movable ramp 820 until the square surface 812 of the needle cover catch 810 has moved distally beyond the square surface 822 of the movable ramp 820 and the distal end of the needle cover catch 810 contacts the platform 840 (due to the resilient bias towards the cassette outer housing 210).

[0274] FIG. 31 C shows the state of the movable ramp 820 and the needle cover catch 810 after the needle cover 240 has moved from its dose delivery position towards its post-dose delivery position. The needle cover catch 810 has now moved proximally with respect to the cassette outer housing 210, maintaining engagement with the platform 840, until the quare surface 812 of the needle cover catch 810 engages with the portion of the square surface 822 of the movable ramp 820 that extends beyond the inner surface of the platform 840, causing the movable ramp 820 to translate proximally with the needle cover catch 810. In doing so, a gap is formed between the shoulder 830 and the square surface 822 of the movable ramp 820 which increases in width as the movable ramp 820 is translated until the width of the gap is sufficient to receive the distal end of the needle cover catch 810, at which point the needle cover catch 810 pivots towards the cassette outer housing such that the distal end of the needle cover catch 810 is received in the gap, as shown in FIG. 31 D. Once the distal end of the needle cover catch 810 is received in the gap formed between the shoulder 830 and the square surface 822 of the movable ramp 820, engagement between the distal end of the needle cover catch and the shoulder 830 inhibits movement of the needle cover 240 back in the distal direction.

[0275] FIG. 32 shows another alternative mechanism for preventing axial translation of the needle sleeve 240. A pin 802 projecting radially outwards from an outer surface of the needle cover 240 is arranged to be received with a track 850 formed in the internal surface of the cassette outer housing 210. The track 850 is shaped such that the needle sleeve 240 is free to translate distally within the cassette outer housing 210 due to the pin 802 traversing a first portion 851 of the track 850 until it abuts a terminal wall 852 of the track 850, corresponding to the needle sleeve 240 being in its dose delivery position. The first potion 851 of the track 850 may be inclined slightly around the circumference of the cassette outer housing 210 such that, as the pin 802 traverses the first portion 851, the needled cover 240 is slightly rotated. As the needle cover 240 is allowed to translate back in a proximal direction from its dose delivery to its post-dose delivery state, the pin 802 now traverses a second portion 853 of the track 850 (due to the previous slight rotation of the needle sleeve 240) until the pin 802 is received in a holding portion 854 of the track 851. The holding potion 854 is shaped to prevent the needle sleeve 240 from once again translating in a distal direction.

[0276] It has previously been discussed in relation to FIG. 9 that the cap 260 is attached to the cassette outer housing 210 through a bayonet-type coupling, where the cap 260 must first be rotated with respect to the cassette outer housing 210 before being axially removed from the remainder of the cartridge 200. However, alternative mechanisms for coupling the cap 260 to the cassette outer housing 210 may be envisaged.

[0277] For example, FIG. 33 shows the proximal end of a cartridge 200 similar to the cartridge 200 described in relation to FIGS. 10A-H, wherein the cap 260 of FIG. 33 has a similar guide pin 267’ to the guide pin 267 as described in relation to FIGS. 10A-H, and a track 270’ similar to the track 270 previously described in relation to FIGS. 10A-H is formed in the inner surface of the cassette outer housing 210. However, in the embodiment of FIG. 33, the track 270’ takes the shape of a partial helix around the axis of the cartridge such that rotation of the cap 260 about the axis of the cartridge and relative to the cassette outer housing 210 is also converted into proximal translation of the cap 260 relative to the cassette outer housing 210. Assuming the cartridge 200 has been coupled to the reusable injector device 100 and therefore the needle sleeve 240 is free to rotate, rotation of the cap 260 will cause the blocking element 266 of the cap to abut the needle cover 240, in turn causing the needle cover 240 to rotate from its initial position to its primed position in a similar manner as previously described. The sloped path of the track 267’ means that as the cap 260 is rotated (twisted) and the guide pin 267’ engages with the track 270’, a resulting force between the guide pin 267’ and the track 270’will cause the cap 260 to axially translate away from the cassette outer housing 210 at the same time as rotating. Once the guide pin 267’ has travelled to the end of the track 270’, the cap 260 can be fully removed from the cassette outer housing 210. This embodiment may provide a simple mechanism for removing the cap 260 that only requires a ‘twisting’ motion by the user on the cap 260. FIG. 34 shows another embodiment for coupling the cap 260 to the cassette outer housing 210 the needle cover has a ramped side surface configured to interact with the projection of the cap. The cap is arranged to follow a linear groove in the cassette outer housing arranged parallel to the axis of the cartridge as the cap is pulled away from the cartridge in a linear distal to proximal direction. As the cap is pulled, the projection abuts the ramp of the needle cover, causing the needle cover to rotate as the projection slides along the ramp, until the projection is able to leave the proximal end of the groove and the cap can be fully separated from the remainder of the cartridge. This embodiment may provide a simple mechanism for removing the cap that only requires a ‘pulling’ motion by the user on the cap.

[0278] FIGS. 35A-C, FIG. 36 and FIG. 37 show different mechanisms for coupling the cartridge 200 to the reusable injector device 100.

[0279] FIGS. 35A-C show a ‘push fit’ connection that uses an interlock arm 722, as described previously. FIG. 35A shows a distal portion of a cartridge 200 coupled to a proximal portion of a reusable injector device 100. The cartridge 200 and reusable injector device 100 may be any cartridge 200 and reusable injector device 100 described herein, for example the cartridge 200 and reusable injector device 100 described in relation to FIG. 5.

[0280] FIG. 35A shows two recesses 710, 710’ formed in the inner surface of the cassette outer housing 210. The two recesses 710, 710’ are located at the distal end of the cassette outer housing 210, in a portion of the cassette outer housing 210 that is received in the housing 110 of the reusable injector device 100. The recesses 710, 710’ are located opposite each other in the cassette outer housing 210, either side of the longitudinal axis of the cartridge 200. The recesses 710, 710’ each extend in a circumferential direction around the inner surface of the cassette outer housing 210 and are each dimensioned to receive an end of a corresponding interlock arm 722’, 722’, as described previously in relation to FIG. 15. As shown in FIG. 35A, the outer radial ends of each interlock arm 722, 722’ are configured to extend into the respective recesses 710, 710’ in the cassette outer housing 210 by a relatively small distance when the cartridge 200 is initially inserted into the reusable injector device 100, thereby coupling the cartridge 200 to the reusable injector device 100. By the interlock arms 722, 722’ extending only a relatively small distance into each respective recess 710, 710’, it may require only a relatively small axial force to be applied by the user to the cartridge 200 to couple the cartridge 200 to the reusable injector device 100 or remove the cartridge 200 from the reusable injector device 100.

[0281] FIGS. 35B and 35C show an interlock arm 722’ engaging with a recess 710’ in more detail. The outer end 724, 724’ of each interlock arm 722, 722’ may comprise a proximal ramped surface 725 and a distal ramped surface 726 to assist with coupling and / or uncoupling of the cartridge 200 from the reusable injector device 100. Each recess 710, 710’ may have a length in the circumferential direction substantially greater than a radial width of the corresponding interlock arm 722, 722’ to allow for rotational tolerance when connecting the cartridge 200 to the reusable injector device 100. While the use of two recesses 710, 710’ and two corresponding interlock arms 722, 722’ have been described, it should be understood that a different number of recesses 710, 710’ could instead be used with the same corresponding number of interlock arms 722, 722’. For example, one recess 710 and one corresponding interlock arm 722 may be present. In other examples, more than two recesses 710, 710’ may be present with the same number of corresponding interlock arms 722, 722’.

[0282] FIG. 36 shows an alternative means for coupling the cartridge 200 to the reusable injector device 100. In this example, the medicament delivery system 10 comprises a threaded connection interface 370 for coupling the cartridge 200 to the reusable injector device 100. An external thread 371 is formed circumferentially around the outer surface of the distal end of the cassette outer housing 210. The external thread 371 is configured to engage with a corresponding internal thread 372 formed circumferentially around the inner surface of the proximal end of the housing 110 of the reusable injector device 100 when the cartridge 200 and the reusable injector device 100 are coupled together. A user couples the cartridge 200 to the reusable injector device 100 by inserting the distal end of the cassette outer housing 210 into the proximal end of the housing 110 of the reusable injector device 100 until the internal thread 372 and the external thread 371 engage. The user then rotates the cartridge 200 about its longitudinal axis relative to the reusable injector device 100 such that the internal thread 372 and the external thread 371 interact with each other, pulling the cartridge 200 and reusable injector device 100 together so that they become coupled. In some examples, the threaded coupling may be used in addition to a coupling provided by the interlock arms 722, 722’.

[0283] FIG. 37 shows another alternative means for coupling the cartridge 200 to the reusable injector device 100. In this example, the cartridge 200 is to be coupled to the reusable injector device 100 using a bayonet coupling 380 provided at the medicament delivery system 10. A pair of bayonet pins 381 extend radially from the outer surface of the distal end of the cassette outer housing 210, in opposite directions, either side of the axis of the cartridge 200. The bayonet pins 318 are located at a portion of the cassette outer housing 210 that will be inserted into the housing 110 of the reusable injector device 100. The bayonet pins 381 are arranged such that they can each be distally inserted into a corresponding L-shaped bayonet groove 382 formed in the inner surface of the proximal end of the housing 110 of the reusable injector device 100. Each bayonet groove 382 has a first elongate portion extending distally from the proximal face of the housing 110 and a second elongate portion extending from the distal end of respective first portion, in a circumferential direction perpendicular to the axis of the reusable injector device 100. To couple the cartridge 200 to the reusable injector device 100, a user aligns each bayonet pin 381 with its corresponding bayonet groove 382. The user then inserts the bayonet pins 381 into the respective first portions of the respective bayonet grooves 382 by pushing the cartridge 200 in an distal axial direction towards the reusable injector device 100, before rotating the cartridge 200 relative to the reusable injector device 100 about the axis of the cartridge 200 such that the bayonet pins 381 translate along the respective second portions of the respective bayonet grooves 382, coupling the cartridge 200 and the reusable injector device 100 together. To uncouple the cartridge 200 and reusable injector device 100, the user performs the aforementioned actions in reverse.

[0284] FIGS. 38A-B illustrate an example operation of the interlock arms 722, 722’ in more detail. FIGS. 38A-B show a distal end of a cartridge 200, including distal ends of the cassette outer housing 210 and needle cover 240. FIGS. 38A-B also show a proximal end of the reusable injector device 100. The cartridge 200 and reusable injector device 100 may be any suitable cartridge 200 and reusable injector device 100 described herein. Certain features such as the pre-filled syringe 230 have been excluded from FIGS. 38A-B for clarity.

[0285] FIG. 38A shows the cartridge 200 coupled to the reusable injector device 100, after a user has axially inserted the distal end of the cassette outer housing 210 into the proximal end of the housing 110 of the reusable injector device 100. The cartridge 200 and reusable injector device 100 may be identical to the cartridge 200 and reusable injector device 100 previously described in relation to FIG. 12 and FIG. 15. FIG. 38A shows the reusable injector device 100 comprising two interlock arms 722, 722’ arranged radially with respect to the longitudinal axis Xs-Xs of the reusable injector device 100, one either side of the plunger rod 170. Each interlock arm 722, 722’ is able translate to in a radial direction towards the plunger rod 170 and a radial direction away from the plunger rod 170, as indicated by the arrows labelled ‘B’. Each interlock arm 722, 722’ is inhibited from moving axially with respect to the longitudinal axis Xs-Xs of the reusable injector device 100.

[0286] The plunger rod 170 may be cylindrical and is generally of a constant diameter D2along its length, as shown in FIG. 38B. However, the plunger rod 170 has at least one recess 730 formed at a proximal end of the plunger rod 170, in the outer circumferential surface of the plunger rod 170, as shown in FIG. 38A, wherein the plunger rod 170 has a diameter Di at the at least one recess 730 that is less than the diameter D2. The at least one recess 730 is arranged to accommodate an inner end 728, 728’ of each interlock arm 722, 722’. In some examples, the at least one recess 730 may comprise an annular groove around the circumference of the plunger rod 170, wherein the annular groove may be able to accommodate one or more of the interlock arms 722, 722’. In other examples, the at least one recess 730 may comprise a plurality of recesses 730 spaced circumferentially around the plunger rod 170, each recess 730 configured to receive at least one corresponding interlock arm 710. FIG. 38A shows the plunger rod 170 further comprising the optional plunger projection 177.

[0287] Each interlock arm 722, 722’ is biased in a neutral radial position by a respective resilient element 727, 727’, as described previously in relation to FIG. 15, such that a portion of the outer end 724, 724’ of each interlock arm 722, 722’ is received in its respective recess 710, 710 in the cassette outer housing 210 and a portion of the inner end 728, 728’ of each interlock arm 722, 722’ is received in the recess 730 (or respective recesses 730) in the cassette outer housing 210. The cartridge 200 is therefore coupled to the reusable injector device 100, however the cartridge 200 may easily be uncoupled and recoupled by moving the cartridge 200 proximally or distally with respect to the reusable injector device 100, as indicated by the arrows labelled ‘A’.

[0288] FIG. 38B shows the cartridge 200 and reusable injector device 100 of FIG. 38A after the plunger rod 170 has been axially translated during a dose dispense operation, for example as previously described in relation to FIG. 20 and FIG. 24. As the plunger rod 170 is moved along the axis Xs-Xs of the reusable injector device 100 in a distal to proximal direction, the at least one recess 730 formed in the plunger rod 170 also moves axially with respect to the interlock arms 722, 722’. During this movement, a distal inner surface of each recess 730 will be brought into abutment with a ramped surface 723, 723’ of a corresponding interlock arm 722, 722’. Continued axial movement of the plunger rod 170 will cause the interlock arms 722, 722’ to each move in radial directions away from the plunger rod 170 and the longitudinal axis Xs-Xs of the reusable injector device 100, as the distal inner surfaces of each recess 730 slide along the corresponding ramped surfaces 723, 723’ of the interlock arms 722, 722’. As the interlock arms 722, 722’ each move in opposing radial directions away from the plunger rod 170, the outer ends 724, 724’ of each interlock arm 722, 722’ are moved further into the corresponding one or more recesses 710, 710’ formed in the cassette outer housing 210, each interlock arm 722, 722’ and corresponding recess 710, 710’ in the cassette outer body 210 together acting as a detent to inhibit axial separation of the cartridge 200 from the reusable injector device 100. The inner ends 728, 728’ of each interlock arm 722, 722’ now abut the circumferential outer surface of the plunger rod 170. The interlock arms are therefore prevented by the circumferential outer surface of the plunger rod 170 from moving in the opposite radial direction, back towards the plunger rod 170 and the longitudinal axis Xs-Xs of the reusable injector device 100. The interlock arms722, 722’ therefore inhibit removal of the cartridge 200 from the reusable injector device 100 for as long as the plunger rod 170 is not in its retracted position (shown in FIG. 38A).

[0289] Once a dose of medicament has been dispensed, the plunger rod 170 is axially translated by any suitable mechanism from its extended position shown in FIG. 38B to its retracted position shown in FIG. 38A. Once the plunger rod 170 has reached its retracted position such that the plunger rod recesses 730, 730’ once again align with the inner ends 728, 728’ of the interlock arms 722, 722’, the interlock arms 722, 722’ will each move in a radial direction back towards the plunger rod 170 and the longitudinal axis Xs-Xsof the reusable injector device 100 so that the inner ends 728, 728’ of each interlock arm 722, 722’ are accommodated within the corresponding at least one recess 730 formed on the plunger rod 170 and the outer ends 724, 724’ of each interlock arm 722, 722’ are at least partially removed from the corresponding at least one recess 710, 710’ formed in the cassette outer housing 210. This situation will be identical to the pre-injection state shown in FIG. 15. The interlock arms 722, 722’ have moved back into the corresponding at least one recesses 730 due to the interlock arms 722, 722’ being biased as discussed previously by respective resilient elements 727, 727’. A user is now able to uncouple the cartridge 200 from the reusable injector device 100 by pulling the cartridge 200 in a distal to proximal direction with respect to the reusable injector device 100. FIGS. 39 and 40A-C are used to illustrate some of the indicators that can be provided as part of a cartridge 200 according to embodiments of the present disclosure.

[0290] FIG. 39 is a side view of a medicament delivery system 10 according to embodiments of the present invention. FIG. 39 shows a cartridge 200 coupled to a reusable injector device 100, which may be any cartridge 200 and reusable injector device 100 disclosed herein. Only a proximal portion of the reusable injector device 100 is shown, with the remainder of the reusable injector device 100 not shown.

[0291] The cartridge 200 comprises a coupling indication feature 430 for indicating to a user whether the cartridge 200 has been correctly coupled to the reusable injector device 100. As an example, the coupling indication feature 430 may comprise a visual indicator provided on the outer surface of the cassette outer housing 210, at a distal end of the cassette outer housing 210. The visual indicator is positioned on the cassette outer housing 210 such that it can indicate whether the cartridge 200 has been correctly coupled to the reusable injector device 100. The visual indicator may comprise a coloured or marked portion of the outer surface of the cassette outer housing 210 that has a different colour or marking to the remainder of the cassette outer housing 210. The location of the visual indicator relative to the reusable injector device 100 may be indicative of whether the cartridge 200 has been correctly coupled to the reusable injector device 100. For example the visual indicator may be positioned on the cassette outer housing 210 such that it is fully (or partially) obscured by the housing 110 of the reusable injector device 100 when the cartridge 200 has been correctly coupled to the reusable injector device 100, but is not fully (or partially) obscured by the housing 110 of the reusable injector device 100 if the cartridge 200 has been incorrectly correctly coupled to the reusable injector device 100.

[0292] FIG. 39 shows the coupling indication feature 430 comprising a first visual indicator 431 and a second visual indicator 432, the first visual indicator 431 and the second visual indicator 432 each comprising a respective band around the outer surface of the cassette outer housing, at a distal end of the cassette outer housing 210. The first visual indicator 431 has a different colour, marking or texture to the second visual indicator 432. The first visual indicator 431 is located adjacent and proximal to the second visual indicator 432. The first visual indicator 431 and the second visual indicator 432 are located on the cassette outer housing 210 such that the second visual indicator 432 is obscured by the proximal end of the housing 110 of the reusable injector device 100 when the cartridge is correctly coupled to the reusable injector device 100, but is visible when the cartridge is not correctly coupled to the reusable injector device 100.

[0293] FIG. 39 shows the cartridge 200 may comprise a cartridge ready indicator 410, for indicating whether the cartridge 200 is ready for an injection to be performed (i.e. the needle cover 240 is in its primed position). The cartridge ready indicator 410 may have a first visual state for indicating that the cartridge 200 is not ready for an injection and a second visual state for indicating that the cartridge 200 is ready for an injection. FIG. 39 shows the cartridge ready indicator 410 comprising an aperture 404 located in the cassette outer housing 210. The aperture 404 may be located such that, when the needle cover 240 is in its initial position, the needle cover 240 is not visible through the aperture 404, which corresponds to the first visual state of the cartridge ready indicator 410. The aperture 404 may also be located such that, when the needle cover 240 is rotated to its primed position, the needle cover 240 is now visible through the aperture 404, which corresponds to the second visual state of the cartridge ready indicator 410.

[0294] FIG. 39 shows the cartridge 200 may comprise a cartridge used indicator 420, for indicating whether the cartridge 200 has already been used to dispense a dose of medicament (i.e. the needle cover 240 is in its post-dose delivery position). The cartridge used indicator 420 may have a first visual state for indicating that the cartridge 200 has not already been used to dispense a dose of medicament and a second visual state for indicating that the cartridge 200 has been used to dispense a dose of medicament. FIG. 39 shows the cartridge used indicator 420 comprising an aperture 421 located in the cassette outer housing 210. The locking recess 617 of the cartridge 200 may form the aperture 421 of the cartridge used indicator 420, with the locking element 612 becoming visible through the aperture 421 once the needle cover 240 has moved to its post-dose delivery position. As such, the first state of the cartridge used indicator 420 may correspond to the locking element 612 not being visible through the aperture 421 while the second state of the cartridge used indicator 420 may correspond to the locking element 612 being visible through the aperture 421.

[0295] FIGS. 40A-C show an example of a cartridge 200 in accordance with embodiments of the present invention, wherein the cartridge 200 has the indicators previously described in relation to FIG. 39. FIG. 40A shows a cartridge 200 before it has been coupled to a reusable injector device 100, where the cap 260 is coupled to the cassette outer housing 210 and the needle cover 240 is in its initial position. The cartridge ready indicator 410 is therefore in a state that indicates to a user that the cartridge 200 has not been primed by moving the needle cover 240 from its initial position to its primed position. As an example, the needle cover 240 may not be visible through the aperture 404 of the cartridge ready indicator 410. The cartridge used indicator 420 is in a state that indicates to a user that the needle cover 240 is not in its post-delivery state and therefore that the cartridge 200 has not yet been used for delivery of a dose of medicament. As an example, the locking element 612 may not be visible through the aperture 421 of the cartridge used indicator 420.

[0296] FIG. 40B shows the cartridge 200 of FIG. 40A, after it has been coupled to a reusable injector device 100 and the cap 260 has been removed. The reusable injector device 100 is not shown, for clarity. The needle cover 240 has been rotated from its initial position to its primed position, for example in response to removal of the cap 260. The cartridge ready indicator 410 is therefore now in a state that indicates to a user that the cartridge 200 is primed and ready for an injection. As an example, the needle cover 240 may now be visible through the aperture 404 of the cartridge ready indicator 410. The cartridge used indicator 420 is still in a state that indicates to a user that the needle cover 240 is not in its post-delivery state and therefore that the cartridge 200 has not yet been used for delivery of a dose of medicament.

[0297] FIG. 40C shows the cartridge 200 of FIG. 40B, after an injection has taken place by pressing the needle cover 240 against an injection site and delivering a dose of medicament. The cartridge used indicator 420 is now in a state that indicates to a user that the needle cover is in its post-delivery state and therefore that the cartridge 200 has been used for delivery of a dose of medicament. As an example, the locking element 612 may now be visible through the aperture 421 of the cartridge used indicator 420.

[0298] FIGS. 41A-E show an example of a medicament delivery system 10 in accordance with embodiments of the present invention, demonstrating the use of the medicament delivery system 10 to administer an injection.

[0299] FIG. 41 A shows the cartridge 200 and the reusable injector device 100 of the medicament delivery system 10 in a separated state, prior to being used for an injection. This state may be similar to the state described previously in relation to FIG. 3. The cap 260 is shown coupled to the cassette outer housing 210 and so a user is protected from the needle 233 inside the cartridge 200. The needle cover 240 will be in its initial position and inhibited from rotating due to the needle cover locking mechanism 250. Since the needle cover 240 cannot be rotated, the cap 260 cannot be removed from the cassette outer housing 210. The cartridge ready indicator 410 is indicating that the cartridge 200 has not yet been primed for an injection. The cartridge used indicator 420 is in a state that indicates that the cartridge 200 has not yet been used for delivery of a dose of medicament.

[0300] FIG. 41 B shows the medicament delivery system 10 of FIG. 41 A, after the cartridge 200 has been coupled to the reusable injector device 100. Such coupling may be achieved by a user inserting the distal end of the cartridge 200 into the proximal end of the reusable injector device 100, in a proximal to distal direction along the longitudinal axis of the reusable injector device 100. The cartridge 200 may be coupled to the reusable injector device 100 by any suitable means described previously, such as a friction fit, push fit, threaded connection, bayonet connection, or the like. This state of the medicament delivery system 10 may be similar to the state described previously in relation to FIG. 5. In this state, the cap 260 remains attached to the cartridge 200, protecting the user from the needle 233. The needle cover 240 has not yet been rotated as previously described in relation to FIG. 9. This is evident from the cartridge ready indicator 410 still not indicating that the cartridge 200 has been primed for an injection. The cartridge used indicator 420 is still in a state that indicates that the cartridge 200 has not yet been used for delivery of a dose of medicament. At this stage it may still be possible for the user to uncouple the cartridge 200 from the reusable injector device 100, if required. Axial movement of the needle cover 240 with respect to the cassette outer housing 210 is inhibited as previously described, however rotation of the needle cover 240 is now possible due to engagement between the needle cover locking mechanism 250 of the cartridge 200 and the unlocking element 350 of the reusable injector device 100, therefore it is possible to remove the cap 260.

[0301] FIG. 41 C shows the medicament delivery system 10 of FIG. 41 D in a state ready for an injection, which may be similar to the state described previously in relation to FIG. 9. The user has now removed the cap 260 from the remainder of the cartridge 200 by rotating the cap 260 relative to the cassette outer housing 210 and reusable injector device 100, as described previously. Such a rotation has also caused the needle cover 240 within the cassette outer housing 210 to rotate, moving the needle cover 240 from its initial position to its primed position and placing the medicament delivery system 10 in a primed state. As a result, the cap 260 can now be fully separated from the cassette outer housing 210 by pulling it in a distal to proximal direction. Removal of the cap 260 now leaves a proximal end of the needle cover 240 extending through the proximal end of the cassette outer housing 210, however the needle 233 remains protected within the needle cover 240. Rotation of the needle cover 240 has caused the cartridge ready indicator 410 to move to its new state indicating that the cartridge 200 has been primed for an injection. Once the needle cover 240 has been rotated into its primed position, rotation back in the opposite direction may be prevented by the rotational stop element 280 as described previously in relation to FIG. 9. Distal axial movement of the needle cover 240 into the cassette outer housing 210 is no longer inhibited at this stage, however the needle cover 240 remains in an extended position covering the needle 233 due to the biasing force provided by the needle cover shuttle 120 and needle cover shuttle spring 121. The cartridge used indicator 420 is still in a state that indicates that the cartridge 200 has not yet been used for delivery of a dose of medicament.

[0302] FIG. 41 D shows the medicament delivery system 10 of FIG. 41 C during an injection of medicament, which may be similar to the state described previously in relation to FIG. 12. The user has placed the proximal end surface of the needle cover 240 onto the injection site and pushed the reusable injector device 100 and cassette outer housing 210 both towards the injection site. As such, a reaction force between the injection site and the proximal end surface of the needle cover 240 has caused the needle cover 240 to translate into the cassette outer housing 210 along the longitudinal axis of the cartridge 210 in a proximal to distal direction, from its primed position to its dose delivery position. As this translation progresses, a proximal end of the needle 233 progressively emerges from the proximal end of the needle cover 240 and is inserted into the injection site. If, at this stage, translation of the plunger rod 170 had not yet begun and the user removes the medicament delivery system 10 from the injection site, the needle cover 240 would translate back out of the cassette outer housing 210 along the longitudinal axis of the cartridge 200 in a distal to proximal direction under the force of the needle cover shuttle spring 121 , progressively covering the needle 233 until the needle 233 is no longer exposed.

[0303] Assuming the user does not abort the injection, an injection process will eventually begin once a translation of the plunger rod 170 is initiated, as described previously. Translation of the plunger rod 170 may, for example, be initiated in response to a detection of the needle sleeve 240 translating at least a threshold distance into the cassette outer housing. In other examples, it may be initiated by a user actuating a trigger button. In other examples the initiation may be automatic, occurring a predetermined period of time after a sensed event, such as connection of the cartridge 200 to the reusable injector device 100, rotation of the cap 260, removal of the cap 260, or axial movement of the needle cover 240. Once translation of the plunger rod 170 has been initiated, the plunger rod 170 translates along the longitudinal axis of the reusable injector device 100 in a distal to proximal direction, translating the piston 235 within the pre-filled syringe 230 and causing a dose of medicament to be expelled from the pre-filled syringe 230 via the needle 233 and into the injection site. During this injection process, uncoupling of the cartridge 200 from the reusable injector device 100 may be inhibited by the engagement of the interlock arm 722 with the plunger rod 170 and the recess 710 of the cassette outer housing 210, as previously described.

[0304] FIG. 41 E shows the medicament delivery system 10 of FIG. 41 D after medicament injection is complete, which may be similar to the state described previously in relation to FIG. 20. The user has removed the medicament delivery system 10 from the injection site, causing the needle cover 240 to axially translate back out of the cassette outer housing 210 along the longitudinal axis of the cartridge 200 in a distal to proximal direction under the force of the needle cover shuttle spring 121, progressively covering the needle 233 until the needle 233 is no longer exposed. The needle cover 240 has now moved from its dose delivery position to its post-dose delivery position. As such, the needle cover return lock 310 is now preventing axial translation of the needle cover 240 back in the distal direction. The cartridge ready indicator 410 still indicates that the cartridge 200 has been primed for an injection. The cartridge used indicator 420 has now changed to a state that indicates that the cartridge 200 has been used for delivery of a dose of medicament. For example, the locking element 612 of the needle cover return lock 310 may now be visible through the cartridge used indicator 420, as previously described.

[0305] For as long as the plunger rod 170 remains in its extended state, removal of the cartridge 200 from the reusable injector device 100 remains inhibited due to the previously- described interaction between the plunger rod 170 , interlock arm 722 and cassette outer housing 210. To uncouple the cartridge 200 from the reusable injector device 100, the plunger rod 170 is moved back to its retracted state by translating the plunger rod 170 in a proximal to distal direction along the longitudinal axis of the reusable injector device 100. This may be achieved using any suitable mechanism. Once the plunger rod 170 is in its retracted state as previously discussed in relation to FIG. 25, the cartridge 200 can be uncoupled from the reusable injector device 100 by moving the cartridge 200 relative to the reusable injector device 100 in a distal to proximal direction along the longitudinal axis of the reusable injector device 100. After the used cartridge 200 and reusable injector device 100 have been separated, the used cartridge 200 can be disposed of and the reusable injector device 100 may be used again with a different cartridge 200. The needle cover 240 of the used cartridge 240 remains inhibited from translating axially into the cassette outer housing by the needle cover return lock 310 and therefore the needle 233 cannot be exposed by accidental movement of the needle cover 240.

[0306] FIG. 42 is a flowchart illustrating an example method 530 for using a medicament delivery system 10 according to embodiments of the present disclosure. The method 530 involves the use of any cartridge 200 and reusable injector device 100 as described in this disclosure.

[0307] In a first step 451 of the method 530, the cartridge 200 is coupled to the reusable injector device 100. The cartridge 200 may be coupled using any coupling method described herein.

[0308] In a second step 452 of the method 530, a dose of medicament is delivered using the medicament delivery system 10. The dose of medicament may be delivered using any method described herein.

[0309] In a third step 453 of the method 530, the cartridge 200 is uncoupled from the reusable injector device 100. The cartridge 200 may be uncoupled using any uncoupling method described herein. The cartridge 200 may then be safely discarded while the reusable injector device 100 can be coupled to a new cartridge 200 to perform a further injection.

[0310] FIG. 43 is a flowchart illustrating another example method 440 for using a medicament delivery system 10 according to embodiments of the present disclosure. The method involves the use of any cartridge 200 and reusable injector device 100 as described in this disclosure.

[0311] In a first step 441 of the method 440, the cartridge 200 is coupled to the reusable injector device 100. The cartridge 200 may be coupled using any coupling method described herein. In a second step 442 of the method 440, a cap 260 is removed from the cartridge. The cap 260 may be removed by any cap removal method described herein, for example. The cap 260 may be removed to cause the needle cover 240 to move from its initial position to its primed position, ready for an injection.

[0312] In a third step 443 of the method 440, the needle cover 240 is moved within the cassette outer housing 210 from its primed position to its dose delivery position. This movement may be caused by pushing the needle cover 240 against an injection site to cause the needle cover 240 to axially translate into the cassette outer housing 210.

[0313] In a fourth step 444 of the method 440, a dose of medicament is delivered using the medicament delivery system 10. The dose of medicament may be delivered using any method described herein.

[0314] In a fifth step 445 of the method 440, the needle cover 240 is moved within the cassette outer housing 210 from its dose delivery position to its post-dose delivery position. This movement may be caused by removing the needle cover 240 from the injection site to cause the needle cover 240 to axially translate out of the cassette outer housing 210.

[0315] In a sixth step 446 of the method 440, the cartridge 200 is uncoupled from the reusable injector device 100. The cartridge 200 may then be safely discarded while the reusable injector device 100 can be coupled to a new cartridge 200 to perform a further injection.

[0316] 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.

[0317] 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.

[0318] 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., short- or 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 dual-chamber cartridge configured to store two or more components of the pharmaceutical formulation 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.

[0319] 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. 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 (anti-diabetic drugs) or 86 (oncology drugs), and Merck Index, 15th -edition.

[0320] 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.

[0321] 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.

[0322] 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.

[0323] 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.

[0324] 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.

[0325] Examples of DPP4 inhibitors are Linagliptin, Vildagliptin, Sitagliptin, Denagliptin, Saxagliptin, Berberine.

[0326] 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.

[0327] 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.

[0328] 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).

[0329] 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 antigenbinding antibody fragments are known in the art.

[0330] 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 primarily responsible 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.

[0331] 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).

[0332] 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.

[0333] 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.

[0334] 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), needle-based 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.

[0335] As further described in ISO 11608-1 :2014(E), a multi-dose container system may involve a needle-based medicament delivery 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 medicament delivery 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).

[0336] As further described in ISO 11608-1 :2014(E), a single-dose container system may involve a needle-based medicament delivery 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 needlebased medicament delivery device with an integrated non-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).

[0337] List of Reference Numbers:

[0338] 10 - medicament delivery system

[0339] 100 - reusable injector device

[0340] 110 - injector housing

[0341] 111 - tubular wall (of injector housing)

[0342] 112 - shuttle blocking element

[0343] 120 - needle cover shuttle

[0344] 121 - needle cover shuttle spring

[0345] 122 - annular wall (of needle cover shuttle)

[0346] 123 - spring blocking element

[0347] 124 - flange (of needle cover shuttle)

[0348] 125 - cutout (of needle cover shuttle)

[0349] 170 - plunger rod

[0350] 171 - plunger rod guide sleeve

[0351] 172 - annular cavity

[0352] 173 - proximal surface (of the plunger rod guide sleeve)

[0353] 174 - cylindrical channel (of plunger rod guide sleeve)

[0354] 177 - piston engagement projection

[0355] 180 - plunger rod driving mechanism

[0356] 200 - cartridge

[0357] 210 - cassette outer housing

[0358] 213 - internal bore

[0359] 214 - pre-filled syringe holder

[0360] 215 - window

[0361] 216 - proximal opening (cassette outer housing)

[0362] 217 - distal opening (cassette outer housing) 230 - pre-filled syringe

[0363] 231 - vial

[0364] 232 - bung

[0365] 233 - needle

[0366] 234 - rigid needle shield

[0367] 235 - piston

[0368] 236 - piston recess

[0369] 240 - needle cover

[0370] 241 - tubular wall (of needle cover)

[0371] 242 - end wall (of needle cover)

[0372] 243 - aperture (of needle cover end wall)

[0373] 244 - side surface (of needle cover)

[0374] 244’ - oblique side surface (of needle cover)

[0375] 250 - needle cover locking mechanism

[0376] 251 - clip

[0377] 252 - first portion (of clip)

[0378] 253 - second portion (of clip)

[0379] 254 - retaining block (of clip)

[0380] 255 - square proximal surface (of retaining block)

[0381] 256 - ramped distal surface (of retaining block)

[0382] 260 - cap

[0383] 261 - tubular wall (cap)

[0384] 262 - end wall (cap)

[0385] 263 - proximal portion (tubular wall of cap)

[0386] 264 - distal portion (tubular wall of cap)

[0387] 266 - blocking element (of cap)

[0388] 267 - guide pin (of cap)

[0389] 270 - track

[0390] 270’ - oblique track

[0391] 270” - straight track

[0392] 271 - first track portion

[0393] 272 - second track portion

[0394] 275 - detent

[0395] 276 - ramped surface (of detent)

[0396] 277 - square surface (of detent)

[0397] 280 - rotational stop element 281 - arm (of rotational stop element)

[0398] 282 - stop projection (of rotational stop element)

[0399] 310 - needle cover return lock

[0400] 310’ - additional needle cover return lock

[0401] 350 - unlocking element

[0402] 352 - proximal ramped surface (of unlocking element)

[0403] 370 - threaded connection interface

[0404] 371 - external thread (of cassette outer housing)

[0405] 372 - internal thread (of injector body)

[0406] 380 - bayonet coupling

[0407] 381 - bayonet pin (of bayonet coupling)

[0408] 382 - bayonet groove (of bayonet coupling)

[0409] 404 - aperture (of cartridge ready indicator)

[0410] 410 - cartridge ready indicator

[0411] 420 - cartridge used indicator

[0412] 421 - aperture (of cartridge used indicator)

[0413] 430 - coupling indication feature

[0414] 431 - first visual indicator

[0415] 432 - second visual indicator

[0416] 501 - first cutout

[0417] 502 - second cutout

[0418] 503 - third cutout

[0419] 505 - crossbar

[0420] 610 - needle cover locking arm

[0421] 612 - locking element (of needle cover locking arm)

[0422] 615 - cassette arm

[0423] 616 - fourth cutout

[0424] 617 - locking recess

[0425] 700 - cartridge coupling feature

[0426] 710 - recess (of cartridge coupling feature)

[0427] 720 - injector coupling feature 722, 722’ - interlock arm

[0428] 723 - ramped surface (of inner end of interlock arm)

[0429] 724 - outer end (of interlock arm)

[0430] 725 - proximal ramped surface (of outer end of interlock arm)

[0431] 726 - distal ramped surface (of outer end of interlock arm)

[0432] 727 - resilient element

[0433] 728 - inner end (of interlock arm)

[0434] 730 - recess (of plunger rod)

[0435] 780 - guide channel (of interlock arm)

[0436] 800 - collar

[0437] 801 - internal track (of collar)

[0438] 802 - pin (for collar)

[0439] 810 - needle cover catch

[0440] 811 - ramped surface (of needle cover catch)

[0441] 812 - square surface (of needle cover catch)

[0442] 820 - movable ramp

[0443] 821 - ramped surface (of movable ramp)

[0444] 822 - square surface (of movable ramp)

[0445] 830 - shoulder (of cassette outer housing)

[0446] 840 - platform (of cassette outer housing)

[0447] 850 - track

[0448] 851 - first track portion

[0449] 852 - terminal wall (of track)

[0450] 853 - second track portion

[0451] 854 - holding portion (of track)

Claims

Claims1. A reusable injector device (100) for use with a cartridge (200), the cartridge comprising a cassette outer housing (210) containing a pre-filled syringe (230) and a needle cover (240), the reusable injector device comprising: a housing (110); a needle cover shuttle (120) displaceable within the housing against a needle cover shuttle spring (121); and a plunger rod (170) configured to dispense medicament from the pre-filed syringe in use; wherein, when the cartridge and the reusable injector device are coupled, the needle cover shuttle engages the needle cover of the cartridge to bias the needle cover in a proximal direction.

2. A reusable injector device according to claim 1, wherein the reusable injector device comprises at least one interlock arm (722, 722’) displaceable to engage a respective recess (710, 710’) in the cassette outer housing to couple the reusable injector device to the cartridge.

3. A reusable injector device according to claim 2, wherein the at least one interlock arm is arranged to be displaced towards the respective recess responsive to displacement of the plunger rod during delivery of medicament.

4. A reusable injector device according to claim 3, wherein the plunger rod comprises at least one recess (730) to receive an outer end (724, 724’) of the at least one interlock arm, wherein the at least one recess and the at least one interlock arm are arranged such that proximal translation of the plunger rod (170) disengages the outer end of the at least one interlock arm from the at least one recess to displace the at least one interlock arm for engaging the recess in the cassette outer housing.

5. A reusable injector device according to any one of claims 1 to 4, wherein uncoupling of the cartridge from the reusable injector device is inhibited during delivery of medicament.

6. A reusable injector device according to any one of claims any one of claims 1 to 5, wherein the reusable injector device comprises an unlocking element (350) configured to engage with a needle cover locking mechanism (250) of the cartridge once the cartridge is coupled to the reusable injector device to allow for rotation of the needle cover with respect to the cassette outer housing.

7. A cartridge (200) for use with a reusable injector device (100), the cartridge comprising: a cassette outer housing (210); a pre-filled syringe (230) arranged within cassette outer housing, the prefilled syringe comprising a needle (233); and a needle cover (240) arranged within the cassette outer housing and surrounding the pre-filled syringe.

8. A cartridge according to claim 7, wherein, when the cartridge is coupled to the reusable injector device: the needle cover is configured to be translated distally within the cassette outer housing from a primed position, in which the needle is surrounded by the needle cover, to a dose delivery position, in which at least a proximal end of the needle extends proximally outside of the needle cover for injection into an injection site; and the needle cover is configured to be translated proximally within the cassette outer housing from the dose delivery position to a post-dose delivery position, in which the needle does not extend proximally outside of the needle cover.

9. A cartridge according to claim 8, wherein, after the needle cover has moved from the dose delivery position to the post-dose delivery position, distal movement of the needle cover is inhibited by a needle cover return lock (310),10. A cartridge according to claim 9, wherein the needle cover return lock comprises a needle cover locking arm (610) extending from the needle cover and a locking recess (617) arranged in the cassette outer housing, the needle cover locking arm configured to become engaged with the locking recess to inhibit distal movement of the needle cover.

11. A cartridge according to claim 8, 9 or 10, wherein the needle cover is configured to be rotated within the cassette outer housing from an initial position to the primed position,and wherein distal translation of the needle cover within the cassette outer housing is inhibited when the needle cover is in the initial position,12. A cartridge according to claim 11 , wherein the cartridge further comprises a cap (260) coupled to the cassette outer housing, wherein rotation of the needle cover from the initial position to the primed position is responsive to removal of the cap from the cassette outer housing.

13. A cartridge according to claim 11 or 12, wherein rotation of the needle cover from the initial position to the primed position is inhibited until the cartridge is coupled to the reusable injector device.

14. A cartridge according to claim 13, wherein rotation of the needle cover from the initial position to the primed position is inhibited by a needle cover locking mechanism (250) of the cartridge, and wherein the needle cover locking mechanism is configured to be engaged by an unlocking element (350) of the reusable injector device when the cartridge is coupled to the reusable injector device, to unlock the needle cover for rotation,15. A cartridge according to claim 14, wherein the needle cover locking mechanism comprises a clip (251) configured to releasably engage with the needle cover to inhibit rotation of the needle cover.

16. A cartridge according to claim 15, wherein the clip is configured to be lifted out of a first cutout (501) in the needle cover by the unlocking element, such that the needle cover is free to rotate from its initial position to its primed position.

17. A cartridge according to any one of claims 11 to 16, wherein, once the cartridge has been coupled to the reusable injector device and the needle sleeve has been rotated from its initial position to its primed position, return rotation back in the opposite direction from the primed position to the initial position is inhibited.

18. A medicament delivery system (10) comprising a reusable injector device (100) and a cartridge (200) for use with the reusable injector device, the cartridge and thereusable injector device being combinable for medicament delivery and separable thereafter, wherein the cartridge comprises: a cassette outer housing (210); a pre-filled syringe (230) arranged within cassette outer housing, the prefilled syringe comprising a needle (233); and a needle cover (240) arranged within the cassette outer housing and surrounding the pre-filled syringe, wherein the reusable injector device comprises: a housing (110); a needle cover shuttle (120) displaceable within the housing against a needle cover shuttle spring (121); and a plunger rod (170) configured to dispense medicament from the pre-filed syringe in use; and wherein, when the cartridge and the reusable injector device are coupled, the needle cover shuttle engages the needle cover to bias the needle cover in a proximal direction.

19. A medicament delivery system according to claim 18, when the cartridge and the reusable injector device are coupled, the needle cover is configured to be translated distally within the cassette outer housing from a primed position, in which the needle is surrounded by the needle cover, to a dose delivery position, in which at least a proximal end of the needle extends proximally outside of the needle cover for injection into an injection site.

20. A medicament delivery system according to claim 18 or 19, wherein the needle cover is configured to be rotated within the cassette outer housing from an initial position to the primed position, and wherein distal translation of the needle cover within the cassette outer housing is inhibited when the needle cover is in the initial position.

21. A medicament delivery system according to claim 18, 19 or 20, wherein rotation of the needle cover from the initial position to the primed position is inhibited until the cartridge is coupled to the reusable injector device.

22. A medicament delivery system according to claim 21 , wherein rotation of the needle cover from the initial position to the primed position is inhibited by a needle coverlocking mechanism (250) of the cartridge, and wherein the needle cover locking mechanism is configured to be engaged by an unlocking element (350) of the reusable injector device when the cartridge is coupled to the reusable injector device, to unlock the needle cover for rotation.

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