Injector device

Abstract

An injector device is held by a user at a holding position, against the force of a spring (204), for dispensing medicament from the device. The device has a needle cover (213, 613, 713) which is axially movable for covering and uncovering a needle (217). The needle cover (213, 613, 713) is biased axially by the spring 204 for covering the needle. The needle cover (213, 613, 713) is movable from a first position, in which the needle cover covers the needle, to the holding position for dispensing medicament. The device has a detent mechanism (231, 331, 431, 531, 631, 731) which is engaged when the needle cover (213, 613, 713) is in the holding position. The detent mechanism applies a resistance force which resists movement of the needle cover (213, 613, 713) towards the first position. The resistance force is less than the force exerted by the spring.

Description

[0001] Injector device

[0002] Field of the invention

[0003] This application relates to an injector device for delivery of a medicament, particularly to an auto-injector device. Background of the invention

[0004] Injector devices are used to deliver a range of medicaments. In an auto-injector device, some or all of the actions required to use the injector device in administering medicament to a user are automated. It is known to provide an auto-injector device having a needle cover which is axially movable to cover and uncover a needle, with the needle cover being biased by a spring to extend over the needle. Typically, the user presses the needle cover against an injection site, against the force of the spring, to push the needle cover into the housing and to uncover the needle which is pushed into the injection site. Medicament is automatically dispensed from the needle via an automated mechanism. A user must typically hold the needle cover in a holding position for a predetermined period of time, to ensure that the correct dose of medicament is dispensed from the device, before removing the device from the injection site. Some users find it difficult to hold the needle cover in the holding position whilst the medicament is dispensed. This may result in pain, discomfort, a wet injection site, early device removal and / or partial delivery of the medicament.

[0005] It is an object of the present invention to provide an injector device that addresses one or more of the problems mentioned above, and to provide an improved injector device.

[0006] Summary of the invention

[0007] The present invention reduces the force required to hold the device at the holding position at which medicament is dispensed from the device. According to the invention there is provided a medicament delivery device for reducing a force required to hold the device at a holding position at which medicament is dispensed from the device, wherein the device comprises a needle for injecting medicament into a user, a needle cover and a body, wherein the needle cover is axially movable relative to the body between a first position, in which the needle cover covers the needle, and a holding position for dispensing medicament from the device, wherein in the holding position the needle protrudes from the distal end of the needle cover, and wherein the device further comprises a spring configured to exert a spring force which biases the needle cover axially, in the distal direction, for the needle cover to cover the needle, and a detent mechanism configured to engage when the needle cover is in the holding position, and wherein when the detent mechanism is engaged it applies a resistance force which resists movement of the needle cover towards the first position, wherein the resistance force is less than the spring force at the holding position. Prior art devices may provide some resistance to the needle cover moving towards the first position, for example through a frictional force between the needle cover and the body, but this resistance is negligible. The present invention provides an additional detent mechanism which is engaged when the needle cover is in the holding position. The detent mechanism applies a resistance force which resists movement of the needle cover towards the first position. The resistance force therefore reduces a user’s force required to hold the device at the holding position (compared to if the detent mechanism was absent). The device therefore may be easier to use and / or safer to use.

[0008] The resistance force is less than the spring force at the holding position. Therefore, when the user reduces their force on the device at the holding position, the spring force can overcome the resistance force and move the needle cover axially for covering cover the needle.

[0009] The detent mechanism may comprise a flexible arm and a cooperating component, wherein the flexible arm is configured to engage with the cooperating component. The flexible arm may be configured to flex to engage with the cooperating component. The flexible arm may be configured to flex radially to engage with the cooperating component. The cooperating component may comprise an aperture, a recess, a ridge or a frictional surface.

[0010] The flexible arm may be connected to the needle cover. The body may comprise the cooperating surface.

[0011] The body may comprise an axially extending slot or recess, and the flexible arm may be configured to move within the axially extending slot or recess when moving between the first position and the holding position. The needle cover may comprise the cooperating component. The flexible arm may be connected to the body.

[0012] The flexible arm may be configured to engage with the cooperating component at or towards a free end of the flexible arm.

[0013] The free end may be towards the proximal end or the distal end of the flexible arm.

[0014] The flexible arm may be configured to engage with the cooperating surface proximally or distally of a free end of the flexible arm.

[0015] The flexible arm may comprise a protrusion configured to engage with the cooperating component in the holding position. The protrusion may be a radially extending protrusion. The protrusion may extend away from the flexible arm in a direction that is radially towards or away from a central axis of the medicament delivery device.

[0016] The protrusion may comprise an engagement surface which engages the cooperating component when the needle cover is in the holding position.

[0017] The engagement surface may be at an acute angle to the longitudinal axis of the medicament delivery device. The engagement surface may be a planar surface.

[0018] The engagement surface may be a first engagement surface. The planar surface may be a first planar surface. The cooperating component may comprise a second planar surface. The first planar surface may engage the second planar surface when the needle cover is in the holding position.

[0019] The first planar surface may be parallel to the second planar surface when the first planar surface engages the second planar surface when the needle cover is in the holding position.

[0020] The engagement surface may comprise a curved surface. The needle cover may be axially movable within the body.

[0021] The device may further comprise a locking mechanism configured to lock the needle cover in a locking position, wherein in the locking position the needle cover covers the needle.

[0022] The locking position may be positioned distally from the first position.

[0023] The locking mechanism may comprise a part of the detent mechanism. The detent mechanism may comprise a flexible arm, and wherein the locking mechanism may comprise the flexible arm and an abutment surface which abut to lock the needle cover in the locked position.

[0024] The detent mechanism may provide haptic feedback to the user when it is engaged in the holding position.

[0025] When the cooperating component comprises the aperture, at least a part of the flexible arm, such as a protrusion, may be visible through the aperture when the detent mechanism is engaged. At least a part of the flexible arm, such as a protrusion may be a different colour to the body.

[0026] The device may comprise an automated mechanism configured to automatically dispense medicament from the device when the needle cover reaches a predetermined axial position, and preferably wherein the predetermined axial position is located distally from the holding position.

[0027] The automated mechanism may comprise a plunger which is automatically released when the needle cover reaches the predetermined axial position.

[0028] The device may comprise a syringe for containing medicament, and wherein when the plunger is released it moves within the syringe for dispensing medicament from the syringe through the needle.

[0029] The device may comprise the medicament.

[0030] The body may be configured to be gripped by a user. The body may form an external part of the device.

[0031] The body may be an internal part of the injector device. The body may be surrounded by an outer housing which is configured to be gripped by a user.

[0032] The present invention further provides a method of using an injector device, the method comprising the steps of pressing a needle cover of the device against an injection site; applying a holding force to the device to hold the needle cover against the injection site whilst medicament is dispensed from the device; and then removing the injector device from the injection site, wherein removing the injector device from the injection site comprises reducing the holding force until a spring force of a spring acting on the needle cover overcomes a resistance force of a detent mechanism of the device to move the needle cover axially to cover the needle.

[0033] The invention further provides a method of using the device which is described herein. The method may include some or all of the following steps: removing a cap from the device; pressing the needle cover of the device against an injection site; holding the needle cover in a holding position when the device is pressed against the injection site, wherein the device may be held in the holding position for a predetermined period of time, wherein medicament may be automatically dispensed from the injection device when the needle cover is in the holding position; removing the device from the injection site, wherein the needle cover may be automatically extended from the device to cover the needle upon removal of the device from the injection site. The method steps may be performed by a user.

[0034] Brief description of the drawings So that the invention may be more fully understood, reference is made to the accompanying drawings in which:

[0035] Figure 1A shows an injector device with a cap attached;

[0036] Figure 1 B shows the injector device of Figure 1 A with the cap removed; Figure 2A shows a simplified view of a prior art injector device prior to use;

[0037] Figure 2B shows a view of the device of Figure 2A with injector device in the holding position;

[0038] Figure 3A shows a simplified cross sectional view of an injector device according to the invention, prior to use; Figure 3B shows a cross sectional view of part the injector device of Fig. 3A, prior to use;

[0039] Figure 3C shows a cross sectional view of part the device of Figure 3A in the holding position;

[0040] Figure 3D shows a cross sectional view of part of the device of Figure 3A in a locked position;

[0041] Figure 4 shows a simplified view of an alternative detent mechanism for a device according to the invention;

[0042] Figure 5 shows a simplified view of an alternative detent mechanism for a device according to the invention; Figure 6 shows a simplified view of an alternative detent mechanism for a device according to the invention;

[0043] Figure 7A shows a view of select components from an alternative injector device according to the invention in an exploded view;

[0044] Figure 7B shows a simplified view of the device of Figure 7A with the components assembled; Figure 7C shows a simplified view of the device of Figure 7B in the holding position;

[0045] Figure 7D shows a simplified cross sectional view of Figure 7C;

[0046] Figure 8A shows a view of an alternative injector device according to the present invention; Figure 8B shows part of the injector device of Fig. 8A prior to use;

[0047] Figure 8C shows part of the injector device of Fig. 8A in the holding position;

[0048] Figure 9 shows a view of an alternative injector device according to the present invention;

[0049] Figure 10 shows a view of an alternative injector device according to the present invention; and

[0050] Figure 11 shows a flow chart illustrating method steps in accordance with the present invention.

[0051] Detailed description drug delivery device, as described herein, may be configured to inject a medicament into a patient. For example, delivery could be sub-cutaneous, 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] Some delivery devices can include one or more functions of a safety syringe, peninjector, 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 auto-injector) and a dose setting mechanism (as typically found in a pen-injector). According to some embodiments of the present disclosure, an exemplary drug delivery device 10 is shown in Figs. 1A & 1 B. Device 10, as described above, is configured to inject a medicament into a patient’s body. Device 10 includes a housing 11 which typically contains a reservoir containing the medicament to be injected (e.g., a syringe) and the components required to facilitate one or more steps of the delivery process.

[0057] Device 10 can also include a cap assembly 12 that can be detachably mounted to the housing 11. Typically a user must remove cap 12 from housing 11 before device 10 can be operated. As shown, housing 11 is substantially cylindrical and has a substantially constant diameter along the longitudinal axis X. The housing 11 has a distal region 20 and a proximal region 21. The term “distal” refers to a location that is relatively closer to a site of injection, and the term "proximal" refers to a location that is relatively further away from the injection site.

[0058] Device 10 can also include a needle sleeve 13 coupled to housing 11 to permit movement of sleeve 13 relative to housing 11. For example, sleeve 13 can move in a longitudinal direction parallel to longitudinal axis X. Specifically, movement of sleeve 13 in a proximal direction can permit a needle 17 to extend from distal region 20 of housing 11.

[0059] Insertion of needle 17 can occur via several mechanisms. For example, needle 17 may be fixedly located relative to housing 11 and initially be located within an extended needle sleeve 13. Proximal movement of sleeve 13 by placing a distal end of sleeve 13 against a patient’s body and moving housing 11 in a distal direction will uncover the distal end of needle 17. Such relative movement allows the distal end of needle 17 to extend into the patient’s body. Such insertion is termed “manual” insertion as needle 17 is manually inserted via the patient’s manual movement of housing 11 relative to sleeve 13.

[0060] Another form of insertion is “automated,” whereby needle 17 moves relative to housing 11. Such insertion can be triggered by movement of sleeve 13 or by another form of activation, such as, for example, a button 22. As shown in Figs. 1A & 1 B, button 22 is located at a proximal end of housing 11. However, in other embodiments, button 22 could be located on a side of housing 11. Other manual or automated features can include drug injection or needle retraction, or both. Injection is the process by which a bung or piston 23 is moved from a proximal location within a syringe (not shown in Figures 1A and 1 B) to a more distal location within the syringe in order to force a medicament from the syringe through needle 17.

[0061] In some embodiments, a drive spring (not shown in Figures 1A and 1 B) is under compression before device 10 is activated. A proximal end of the drive spring can be fixed within proximal region 21 of housing 11, and a distal end of the drive spring can be configured to apply a compressive force to a proximal surface of piston 23. Following activation, at least part of the energy stored in the drive spring can be applied to the proximal surface of piston 23. This compressive force can act on piston 23 to move it in a distal direction. Such distal movement acts to compress the liquid medicament within the syringe, forcing it out of needle 17. Following injection, needle 17 can be retracted within sleeve 13 or housing 11. Retraction can occur when sleeve 13 moves distally as a user removes device 10 from a patient’s body. This can occur as needle 17 remains fixedly located relative to housing 11. Once a distal end of sleeve 13 has moved past a distal end of needle 17, and needle 17 is covered, sleeve 13 can be locked. Such locking can include locking any proximal movement of sleeve 13 relative to housing 11.

[0062] Another form of needle retraction can occur if needle 17 is moved relative to housing 11. Such movement can occur if the syringe within housing 11 is moved in a proximal direction relative to housing 11. This proximal movement can be achieved by using a retraction spring (not shown), located in distal region 20. A compressed retraction spring, when activated, can supply sufficient force to the syringe to move it in a proximal direction. Following sufficient retraction, any relative movement between needle 17 and housing 11 can be locked with a locking mechanism. In addition, button 22 or other components of device 10 can be locked as required.

[0063] Figures 2A and 2B show a simplified view of a prior art device 110 having a needle cover 103 which is axially movable to cover and uncover the needle 117. The needle cover 113 is biased by a spring 104 to extend over the needle. Figure 2A shows the device before use, in which the needle cover 113 covers the needle 117. A force must be applied by a user against the spring force 125 in moving the needle cover 113 from the position shown in Figure 2A towards a holding position shown in Figure 2B, and a holding force 120 must be applied to maintain the needle cover in the holding position.

[0064] Typically the user presses the needle cover 113 against an injection site 115 to push the needle cover 113 at least partially into the housing. The exposed needle 117 is pushed into the injection site 115. In the holding position, medicament is automatically dispensed from the needle 117 via an automated mechanism (not shown). A user must typically hold the needle cover 113 in the holding position for a predetermined period of time, to ensure that the correct dose of medicament is dispensed from the device 110, before removing the device from the injection site 115. Figure 3A to 3D shows features of an embodiment of a medicament delivery device 210, which is also referred to herein as an injector device, according to the invention. The device has a distal end 271 and a proximal end 272. The device 210 has a needle 217 for injecting medicament into a user at an injection site, a needle cover 213 and a body 203. The body 203 is configured to be gripped by a user. The body 203 forms part of the external surface of the device. The device of Figures 3A to 3D has a longitudinal axis 250.

[0065] The needle cover 213 is axially movable relative to the body 203 between a first position, shown in Figures 3A and 3B, in which the needle cover 213 covers the needle 217, and a holding position, shown in Figure 3C, for dispensing medicament from the device. In the holding position, the needle 217 protrudes from the distal end of the needle cover 213.

[0066] A spring 204 exerts a spring force against the needle cover 213 which biases the needle cover axially, in the distal direction.

[0067] A force must be applied by a user against the force of the spring 204 in moving the needle cover 213 from the position shown in Figures 3A and 3B towards the holding position shown in Figure 3C. A holding force must be applied by a user to maintain the needle cover 213 in the holding position. Medicament is dispensed from the injector device 210 via the needle 217 whilst the needle cover is in the holding position. An automated mechanism is triggered to start the dispensing of medicament when the needle cover 217 reaches a predetermined axial position within the housing. The predetermined position may be located just distally of the holding position.

[0068] The automated mechanism may comprise a plunger 291 which is automatically released when the needle cover reaches the predetermined axial position. When the plunger 291 is released it moves within the syringe 221 to dispense medicament from the syringe 221 through the needle 217. Automated mechanisms are well known in the prior art and shall not be further described.

[0069] Typically the user removes a cap (not shown) from the distal end of the injector device.

[0070] The user presses the needle cover 213 against an injection site to move the needle cover 213 axially relative to the body 203 and to uncover the needle 217. The needle 217 is pushed into the injection site. The automated mechanism is released, and medicament is automatically dispensed from the device via the needle 217. The user holds the needle cover 213 in the holding position whilst the medicament is dispensed. A user must typically exert a holding force to hold the needle cover 213 in the holding position for a predetermined period of time, to ensure that the correct dose of medicament is dispensed from the device 210, before removing the device 210 from the injection site.

[0071] A detent mechanism 231 is configured to engage when the needle cover 213 is in the holding position. When the detent mechanism 231 is engaged it applies a resistance force which resists movement of the needle cover 213 towards the first position. The resistance force acts against the force of the spring 204. The resistance force is less than the spring force of the spring 204 at the holding position. The detent mechanism 231 may provide haptic feedback to the user when it is engaged. The detent mechanism 231 comprises a flexible arm 230 and a cooperating component. In Figures 3A to 3D the cooperating component 240 comprises an aperture in the form of a slot 240 formed in the body 203. The flexible arm 230 is connected to the needle cover 213 and, in the example shown in Figures 3A to 3D, the flexible arm 230 is integrally formed with the needle cover 213. The flexible arm 230 is configured to flex radially towards the slot 240 so that a protrusion 232, which is also referred to herein as a radially-extending protrusion, on a free end 233 of the flexible arm engages with the slot 240 when the needle cover is 213 is in the holding position, as shown in Figure 3C. The protrusion 232 and the slot 240 engage to provide the resistance force against the force of the spring 204.

[0072] The resistance force has a frictional component, parallel to the engagement surface of the protrusion 232 and the slot 240, and a normal component which is perpendicular to the engagement surface. The radially-extending protrusion 232 is visible through the slot 240 when the detent mechanism is engaged. The engagement therefore provides a visible indicator to the user that the detent mechanism is engaged, and hence that the holding force is reduced. The flexible arm 230 is a different colour to the body 203 which enhances the user visually identifying that the detent mechanism 231 is engaged. Alternatively, only the radially-extending protrusion 232 on the flexible arm 230 is a different colour to the body 203 to enhance the user visually identifying that the detent mechanism 231 is engaged.

[0073] In an alternative embodiment, the radially-extending protrusion 232 is provided towards but not at the free end 233 of the flexible arm 230.

[0074] The free end 233 of the flexible arm 230 is towards the proximal end of the needle cover 213. The flexible arm 230 forms a sprung arm which is biased radially outwardly. The radially-extending protrusion 232 is biased towards the slot 240. In a free state, the flexible arm 230 is wider than when constrained within the device 210.

[0075] In an alternative embodiment (not shown), the flexible arm 230 could be a separate part which is connected to the needle cover 213. The flexible arm 230 could alternatively or additionally have a means for biasing the flexible arm towards the cooperating component, such as a spring for aiding the engagement of the flexible arm and the cooperating component (not shown). The body 203 has an axially extending recess 260 which extends axially along at least part of the length of the body. The free end 233 of the flexible arm 230 is received and moves within in the axially extending recess 260, when the needle cover 213 is moved between the first position and the holding position. The recess 260 reduces the frictional force between the flexible arm 230 and the internal sides of the needle cover 213, compared to if no recess was present. The flexible arm is under less tension when it can expand to a greater radial extent within the recess. The user therefore does not have to press as hard to move the needle cover 213 axially. Alternatively, the recess 260 could be a slot which extends through the needle cover 213.

[0076] Although the description describes the features of a flexible arm, the example shown in Figures 3A to 3D has two flexible arms 230, which are on opposite sides of the needle cover 213 and each of the flexible arms 230 has the same features as described in relation to a singular flexible arm 230. It is noted that just one flexible arm 230 could be provided with the device, or more than two flexible arms could be provided, each having the same features as described herein. If more than one flexible arm 230 is provided then each flexible arm 230 could cooperate with a separate cooperating component 240 in the holding position, with each of the cooperating components having the same features as described herein in relation to a single cooperating component.

[0077] When the needle cover is in the holding position, medicament is automatically dispensed from the device. The medicament is contained in a syringe 221. The syringe 221 comprises a container 220 for holding the medicament and the needle 217. The automated mechanism comprises a plunger 291 which is automatically released to dispense medicament from the device. The plunger moves distally within the syringe under the force of a plunger drive spring for automatically dispensing medicament from the container 220 through the needle 217. The syringe may be prefilled with medicament so that the user does not fill the syringe themselves.

[0078] In an alternative to the syringe, the device 210 may comprise a cartridge for containing medicament and a needle which are separated in the first position, and wherein the proximal end of the needle is engaged with the cartridge in the holding position for dispensing the medicament via the needle.

[0079] In use, a user applies a force against the spring force of the spring 204 to move the needle cover 213 from a first position towards a holding position. Typically the user presses the needle cover 213 against an injection site to push the needle cover 213 into the body 203, and the uncovered needle 217 into an injection site.

[0080] The automated mechanism is released, and medicament is automatically dispensed from the device via the needle 217. A user exerts a holding force to hold the needle cover 213 in the holding position whilst the medicament is dispensed. The needle may be held in the holding position for a predetermined period of time, for example 10 seconds, to ensure that the correct dose of medicament is dispensed from the device 210, before removing the device from the injection site.

[0081] In the holding position, the holding force of the user acts against the force of the spring 204. However, the force of the spring 204 is reduced by the resistance force provided by the detent mechanism 231 which is engaged in the holding position. After the medicament has been dispensed from the device, the user reduces their holding force until the spring force overcomes the resistance force. The force of the spring 204 then disengages the radially-extending protrusion 232 from the slot 240, and moves the needle cover 213 axially away from the holding position to cover the needle 217 as it is removed from the injection site.

[0082] The method may include removing a cap from the device prior to use.

[0083] The device 210 further comprises a locking mechanism 280 configured to lock the needle cover 213 in a locking position as shown, for example, in Figure 3D. The needle cover 213 is located at a more distal position in the locking position compared to the first position. In the locking position the needle cover 213 covers the needle 217 and is prevented from moving proximally to uncover the needle. The locking mechanism is engaged after the medicament has been dispensed from the device. The locking mechanism 280 comprises the flexible arm 230 and a locking protrusion 263 with an abutment surface 261. The locking protrusion 263 is provided on the body 203. The abutment surface 261 engages the free end 233 of the flexible arm in the locking position to prevent proximal movement of the needle cover 213.

[0084] In use, after the medicament has been dispensed from the device, the needle cover 213 moves distally within the body under the force of the spring 204, and covers the needle 217. The flexible arm 230 flexes radially inwardly to move past the locking protrusion 263. The needle cover 213 is then prevented from moving proximally since the free end 233 of the flexible arm 230 engages the abutment surface 261.

[0085] The holding force of the user required to hold the needle cover in the holding position may be around 10N without the detent mechanism, for example. However, including the detent mechanism in the device may reduce the holding force by around 2.5N.

[0086] The size of the resistance force which is applied by the detent mechanism 231 can be modified by changing one or more of the angle of the surface of the cooperating component which engages with the flexible arm; the material of the flexible arm and / or the material of the cooperating component to modify the frictional force when they engage; and the flexural stiffness of the flexible arm 230.

[0087] Figures 4, 5 and 6 show alternative forms for the cooperating component which may be used in any of the other embodiments shown and described herein, including the embodiments shown and described in relation to Figures 3A to D, Figures 7A to D, Figure 8A to C and Figures 9 and 10.

[0088] Figure 4 shows a detent mechanism 331 in which the cooperating component comprises an aperture in the form of a slot 340 which extends through the thickness of the component 313 in which it is located. The component 313 may be a body of a medicament device or a needle cover, for example. A protrusion 332, which is also referred to as a radially-extending protrusion, on the flexible arm 330 engages with the slot 340 in the holding position.

[0089] The protrusion 332 comprises an engagement surface 341 which engages with the slot 340 when the needle cover is in the holding position. The engagement surface 341 is at an acute angle to the longitudinal axis of the medicament delivery device. Having the engagement surface at an acute angle may facilitate the disengagement of the protrusion 332 from the cooperating component under the spring force. The engagement surface 341 is a planar surface. In another embodiment, the engagement surface 341 is a curved surface.

[0090] Figure 5 shows a detent mechanism 431 in which the cooperating component comprises a recess 440 in the component 413 in which it is located. The component 413 may be a body of a medicament device or a needle cover, for example. A protrusion 432 on the flexible arm 430 engages with the recess 440 in the holding position.

[0091] The protrusion 432 comprises an engagement surface 441 which engages with the recess 440 when the needle cover is in the holding position. The engagement surface 441 is at an acute angle to the longitudinal axis of the medicament delivery device.

[0092] The engagement surface 441 is a planar surface. In another embodiment, the engagement surface 441 is a curved surface. Figure 6 shows a detent mechanism 531 in which the cooperating component comprises a ridge 540 on the component 513 in which it is located. The component 513 may be a body of a medicament device or a needle cover, for example. The ridge 540 may extend towards the protrusion 532 on the flexible arm 530. The protrusion 532 on the flexible arm engages with a surface of the ridge 540 in the holding position. The ridge 540 may be formed from a rigid plastic material, or an o-ring or compressible rubber, for example.

[0093] The protrusion 532 comprises an engagement surface 541 which engages with the ridge 540 when the needle cover is in the holding position. The engagement surface 541 is at an acute angle to the longitudinal axis of the medicament delivery device.

[0094] The engagement surface 541 is a planar surface. The engagement surface 541 is a first engagement surface. The cooperating component, in this example formed as a ridge 541, has a second engagement surface 542 which is a planar surface. The planar surface of the second engagement surface 542 is parallel to the planar surface of the first engagement surface 541 when the first planar surface 541 engages the second planar surface when the needle cover is in the holding position.

[0095] In another embodiment, the engagement surface 541 is a curved surface.

[0096] In another embodiment, the slot 340 of Figure 4 could have a second engagement surface which is a planar surface. The planar surface of the second engagement surface may be parallel to the planar surface of the first engagement surface 341 when the first planar surface 341 engages the second planar surface when the needle cover is in the holding position.

[0097] In another embodiment, the recess 440 of Figure 5 could have a second engagement surface which is a planar surface. The planar surface of the second engagement surface may be parallel to the planar surface of the first engagement surface 441 when the first planar surface 441 engages the second planar surface when the needle cover is in the holding position.

[0098] Alternatively, the cooperating component may comprise a frictional surface (not shown), which may be formed from rubber, for example. The frictional surface may be provided on the body or the needle cover. The frictional surface may be flush with the body or the needle cover. The flexible arm may have a corresponding surface which engages with the frictional surface on the body or the needle cover. The flexible arm does not need to have a protrusion to engage with the frictional surface on the body or the needle cover. The detent mechanism comprises the frictional surface on the body or the needle cover, and the surface on the flexible arm, which engage when the needle cover is in the holding position. The frictional surface on the body or the needle cover may be around 2mm long.

[0099] Although figures 4, 5 and 6 show the radially extending protrusion 332, 432, 532 to be on a free end of a flexible arm, the radially extending protrusion could alternatively be located away from the free end of the flexible arm, as shown, for example, in Figures 7 A to 7D.

[0100] The embodiment shown in Figures 7A to D has corresponding features to those explained above in relation to Figures 3A to 3C. However, in figures 7A to 7D, the radially extending protrusion 632 is located distally from the free end 633 of the flexible arm 630. The medicament delivery device 610 of Figures 7A to 7D has a longitudinal axis 650, a proximal end 672 and a distal end 671. Figure 7A shows the body 703 and the needle cover 613 as separate parts in an exploded view.

[0101] The detent mechanism 631 comprises the flexible arm 630 and an aperture in the form of a slot 640 formed in the body 603. The flexible arm 630 is integrally formed with the needle cover 613. The flexible arm 630 is configured to flex radially towards the slot 640 so that a protrusion 632, also referred to as a radially-extending protrusion, engages with the slot 640 when the needle cover is in the holding position, shown in Figures 7C and 7D. Figure 7B slows the slot 640 when the radially-extending protrusion 632 is not located within the slot. The detent mechanism 631 may provide haptic feedback to the user when it is engaged. The radially-extending protrusion 632 is visible through the slot 640 when the detent mechanism is engaged. The engagement therefore provides a visible indicator to the user that the detent mechanism is engaged and hence that the holding force is reduced. The flexible arm 630 is a different colour to the body 603 which enhances the user visually identifying that the detent mechanism 631 is engaged. Alternatively, only the radially-extending protrusion 632 on the flexible arm 630 is a different colour to the body 603 to enhance the user visually identifying that the detent mechanism 631 is engaged.

[0102] The flexible arm 630 forms a sprung arm which is biased radially outwardly. The radially-extending protrusion 632 is biased towards the slot 640. In a free state, the flexible arm 630 is wider than when constrained within the device 610.

[0103] The example shown in Figures 7A to 7D has two flexible arms 630, each having a radially extending protrusion 632 located distally from the free end 633 of the flexible arm 630 for engaging with a corresponding slot, although just one flexible arm 630 or more than two flexible arms may be provided.

[0104] The embodiment shown in Figure 8A to 8C has corresponding features to those explained above in relation to Figures 3A to 3D. However, in Figure 8A to 8C, the body 703 is an internal component of the injector device 710. The body 703 additionally functions to hold a drive spring (not show) which is releasable to automatically move the plunger and dispense medicament from the device. The body 703 is surrounded by an outer housing 721 which is configured to be gripped by a user.

[0105] The flexible arms 730 are connected to the body 703 of the injector device 710. The cooperating component in the form of a recess 740 is provided on the needle cover 713. The device of Figures 8A to 8C has a longitudinal axis 750. The detent mechanism 731 comprises the flexible arm 730 and the recess 740. The flexible arm 730 is integrally formed with the body 703, although in an alternative embodiment the flexible arm 730 could be a separate component which is joined to the body 703. The flexible arm 730 is configured to flex towards the recess 740 so that a protrusion 732 on the flexible arm 730 engages with the recess 740 when the needle cover is in the holding position, as shown in Fig. 8C. The detent mechanism 731 may provide haptic feedback to the user when it is engaged.

[0106] The flexible arm 730 forms a sprung arm which is biased towards the recess 740. The protrusion 732 is biased towards the recess 740.

[0107] The protrusion is at a free end 733 of the flexible arm 730. However, alternatively, the protrusion 732 may be towards but not at the free end 733 of the flexible arm. The protrusion 732 may be located proximally from the free end of the flexible arm 733. The example shown in Figure 8 has two flexible arms 730 each having a radially extending protrusion 732 for engaging with a corresponding recess 740, although just one flexible arm 730 or more than two flexible arms may be provided.

[0108] In an alternative embodiment (not shown), the body 703 in figures 8A to 8C may form an external part of the device which is configured to be gripped by a user, and have the same features of the detent mechanism 713 as described above in relation to figs. 8A to 8C, such that the flexible arm 730 is provided on the body and the recess 740 is provided on the needle cover. The embodiment shown in Figure 9 has corresponding features to those explained above in relation to Figures 3A to 3D. However, in Figure 9, the body 803 is an internal component of the injector device 810. The body 803 additionally functions to hold a drive spring (not show) which is released to automatically move the plunger and dispense medicament from the device. The body 803 is surrounded by an outer housing (not shown) which is configured to be gripped by a user.

[0109] The flexible arms 830 are connected to the needle cover 813 of the injector device 810. The cooperating component in the form of a recess 840 is provided on the body 803. The detent mechanism 831 comprises the flexible arm 830 and the recess 840. The flexible arm 830 is integrally formed with the needle cover 813, although in an alternative embodiment the flexible arm 830 could be a separate component which is joined to the needle cover 813. The flexible arm 830 is configured to flex towards the recess 840 so that a protrusion 832 on a free end 833 of the flexible arm 830 engages with the recess 840 when the needle cover is in the holding position, as shown in Fig.

[0110] 9. The detent mechanism 831 may provide haptic feedback to the user when it is engaged.

[0111] The flexible arm 830 forms a sprung arm which is biased towards the recess 840. The protrusion 832 is biased towards the recess 840.

[0112] Alternatively, the protrusion 832 may be towards but not at the free end 833 of the flexible arm. The protrusion 832 may be located proximally from the free end of the flexible arm 833.

[0113] Alternatively, as shown in Fig. 10, the detent mechanism 931 comprises an aperture 940 in the needle cover 913, which engages with a protrusion 932 on a free end 933 of a flexible arm 930 on the body 903, when the injector device 910 is in the holding position. Figure 11 is a flow chart, illustrating example method steps in accordance with an embodiment of the invention. The method steps in Figure 11 may describe the operation of any of the injector devices disclosed herein. As noted, the injector device is also referred to herein as a medicament delivery device. If a needle cap is present on a distal end of the injector device, the needle cap is removed from the device in step 1010. This step 1010 is optional since the device may not have a needle cap.

[0114] A user then presses the needle cover of the injector device against an injection site in step 1011. This moves the needle cover axially for uncovering the needle, and the needle is inserted into the skin at the injection site. In this step, the needle cover moves from a first position, covering the needle, to a holding position at which medicament is dispensed from the device. The device has a detent mechanism which engages when the needle cover is in the holding position. user then applies a holding force to hold the injector device against the skin in step 1012 for dispensing medicament from the device. In this step the needle cover of the injector device is in a holding position. The user may apply the holding force for a predetermined period of time, for example 10 seconds, to ensure that the medicament is dispensed at the correct dose.

[0115] Then, in step 1013, the user removes the injector device from the injection site. The user reduces their holding force until a spring force of a spring acting on the needle cover overcomes the resistance force of the detent mechanism to move the needle cover axially to cover the needle.

[0116] List of features:

[0117] 10 - device

[0118] 11 - housing 12 - cap

[0119] 13 - needle sleeve

[0120] 17 - needle

[0121] 20 - distal region

[0122] 21 - proximal region 22 - button 103 - needle cover

[0123] 104 - spring

[0124] 110 - device

[0125] 113 - needle cover 115 - injection site

[0126] 117 - needle

[0127] 120 - holding force

[0128] 125 - spring force

[0129] 203 - body 204 - spring

[0130] 210 - medicament delivery device

[0131] 213 - needle cover

[0132] 217 - needle

[0133] 220 - container 221 - syringe

[0134] 230 - flexible arm

[0135] 231 - detent mechanism

[0136] 232 - protrusion

[0137] 233 - free end 240 - slot

[0138] 250 - longitudinal axis

[0139] 260 - axially extending recess

[0140] 261 - abutment surface

[0141] 263 - locking protrusion 271 - distal end

[0142] 272 - proximal end

[0143] 280 - locking mechanism

[0144] 313 - component

[0145] 330 - flexible arm 331 - detent mechanism

[0146] 332 - protrusion

[0147] 340 - slot

[0148] 341 - engagement surface

[0149] 413 - component 430 - flexible arm 431 - detent mechanism

[0150] 432 - protrusion

[0151] 440 - recess

[0152] 441 - engagement surface 513 - component

[0153] 530 - flexible arm

[0154] 531 - detent mechanism

[0155] 532 - protrusion540 - ridge

[0156] 541 - engagement surface 542 - engagement surface

[0157] 603 - body

[0158] 613 - needle cover

[0159] 630 - flexible arm

[0160] 631 - detent mechanism 632 - protrusion

[0161] 633 - free end

[0162] 640 - slot

[0163] 650 - longitudinal axis

[0164] 671 - distal end 672 - proximal end

[0165] 703 - body

[0166] 713 - needle cover

[0167] 730 - flexible arm

[0168] 731 - detent mechanism 732 - protrusion

[0169] 733 - free end

[0170] 740 - recess

[0171] 750 - longitudinal axis

[0172] 803 - body 810 - injector device

[0173] 813 - needle cover

[0174] 830 - flexible arm

[0175] 831 - detent mechanism

[0176] 832 - protrusion 833 - free end 840 - recess

[0177] 903 - body

[0178] 910 - injector device

[0179] 913 - needle cover 930 - flexible arm

[0180] 931 - detent mechanism

[0181] 932 - protrusion

[0182] 933 - free end

[0183] 940 - aperture 1010 - method step

[0184] 1011 - method step

[0185] 1012 - method step

[0186] 1013 - method step 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. 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. 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.

[0187] 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.

[0188] 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.

[0189] 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. 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. 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.

[0190] 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.

[0191] Examples of DPP4 inhibitors are Linagliptin, Vildagliptin, Sitagliptin, Denagliptin, Saxagliptin, Berberine.

[0192] Examples of hormones include hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists, such as Gonadotropine (Follitropin,

[0193] Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, and Goserelin. Examples of polysaccharides include a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra-low molecular weight heparin or a derivative thereof, or a sulphated polysaccharide, e.g. a poly-sulphated form of the above-mentioned polysaccharides, and / or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium. An example of a hyaluronic acid derivative is Hylan G-F 20 (Synvisc®), a sodium hyaluronate.

[0194] The term “antibody”, as used herein, refers to an immunoglobulin molecule or an antigen-binding portion thereof. Examples of antigen-binding portions of immunoglobulin molecules include F(ab) and F(ab')2 fragments, which retain the ability to bind antigen. 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).

[0195] The terms “fragment” or “antibody fragment” refer to a polypeptide derived from an antibody polypeptide molecule (e.g., an antibody heavy and / or light chain polypeptide) that does not comprise a full-length antibody polypeptide, but that still comprises at least a portion of a full-length antibody polypeptide that is capable of binding to an antigen. Antibody fragments can comprise a cleaved portion of a full length antibody polypeptide, although the term is not limited to such cleaved fragments. Antibody fragments that are useful in the present invention include, for example, Fab fragments, F(ab')2 fragments, scFv (single-chain Fv) fragments, linear antibodies, monospecific or multispecific antibody fragments such as bispecific, trispecific, tetraspecific and multispecific antibodies (e.g., diabodies, triabodies, tetrabodies), monovalent or multivalent antibody fragments such as bivalent, trivalent, tetravalent and multivalent antibodies, minibodies, chelating recombinant antibodies, tribodies or bibodies, intrabodies, nanobodies, small modular immunopharmaceuticals (SMIP), binding- domain immunoglobulin fusion proteins, camelized antibodies, and VHH containing antibodies. Additional examples of antigen-binding antibody fragments are known in the art.

[0196] 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. 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).

[0197] 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.

[0198] 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. 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.

[0199] As further described in ISO 11608-1 :2014(E), a multi-dose container system may involve a needle-based injection device with a replaceable container. In such a system, each container holds multiple doses, the size of which may be fixed or variable (pre-set by the user). Another multi-dose container system may involve a needle-based injection device with an integrated non-replaceable container. In such a system, each container holds multiple doses, the size of which may be fixed or variable (pre-set by the user). As further described in ISO 11608-1 :2014(E), a single-dose container system may involve a needle-based injection device with a replaceable container. In one example for such a system, each container holds a single dose, whereby the entire deliverable volume is expelled (full evacuation). In a further example, each container holds a single dose, whereby a portion of the deliverable volume is expelled (partial evacuation). As also described in ISO 11608-1 :2014(E), a single-dose container system may involve a needle-based injection device with an 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).

[0200] Those of skill in the art will understand that modifications (additions and / or removals) of various components of the 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.

Claims

PAT23164-EP-EPAClaims1. A medicament delivery device for reducing a force required to hold the device at a holding position at which medicament is dispensed from the device, wherein the device comprises: a needle (217) for injecting medicament into a user, a needle cover (213, 613, 713, 813, 913) and a body (203, 603, 703, 803, 903), wherein the needle cover (213, 613, 713, 813, 913) is axially movable relative to the body (203, 603, 703, 803, 903) between a first position, in which the needle cover (213, 613, 713, 813, 913) covers the needle (217), and a holding position for dispensing medicament from the device, wherein in the holding position the needle (217) protrudes from the distal end of the needle cover (213, 613, 713, 813, 913), and wherein the device further comprises: a spring (204) configured to exert a spring force which biases the needle cover axially, in the distal direction, for the needle cover (213, 613, 713, 813, 913) to cover the needle (217), and a detent mechanism (231, 331, 431, 531, 631, 731 , 831, 931) configured to engage when the needle cover (213, 613, 713, 813, 913) is in the holding position, and wherein when the detent mechanism (231, 331, 431, 531, 631 , 731, 831, 931) is engaged it applies a resistance force which resists movement of the needle cover (213, 613, 713, 813, 913) towards the first position, wherein the resistance force is less than the spring force at the holding position.

2. The medicament delivery device according to claim 1, wherein the detent mechanism (231 , 331 , 431 , 531 , 631 , 731 , 831 , 931) comprises a flexible arm(230, 330, 430, 530, 630, 730, 830, 930) and a cooperating component (240, 340, 440, 540, 640, 740, 840, 940), wherein the flexible arm is configured to engage with the cooperating component.

3. The medicament delivery device according to claim 2, wherein the flexible arm (230, 330, 430, 530, 630, 730, 840, 940) is configured to flex to engage with the cooperating component (240, 340, 440, 540, 640, 740, 840, 940).

4. The medicament delivery device according to claim 2 or 3, wherein the cooperating component comprises an aperture (240, 340, 640, 940), a recess (440, 740, 840), a ridge (540) or a frictional surface.

5. The medicament delivery device according to any one of claims 2, 3 or 4, wherein the flexible arm (230, 330, 430, 530, 630, 730, 830) is connected to the needle cover, and preferably wherein the body (203, 603, 803) comprises the cooperating surface.

6. The medicament delivery device according to any one of claims 2, 3, or 4 wherein the needle cover comprises the cooperating component and preferably wherein the flexible arm (730) is connected to the body (703).

7. The medicament delivery device according to any one of claims 2 to 6, wherein the flexible arm (230, 330, 430, 530, 630, 730) comprises a protrusion (232,332, 432, 532, 632, 732) configured to engage with the cooperating component in the holding position.

8. The medicament delivery device according to claim 7, wherein the protrusion (232, 332, 432, 532, 632, 732) comprises an engagement surface (341) which engages the cooperating component when the needle cover is in the holding position.

9. The medicament delivery device according to claim 8, wherein the engagement surface (341) is at an acute angle to the longitudinal axis (250, 650, 750) of the medicament delivery device.

10. The medicament delivery device according to claim 8 or 9, wherein the engagement surface (341) is a planar surface.

11. The medicament delivery device according to claim 10, wherein the engagement surface (341) is a first engagement surface and the planar surface is a first planar surface, and wherein the cooperating component comprises a second planar surface, wherein the first planar surface engages the second planar surface when the needle cover is in the holding position.

12. The medicament delivery device according to claim 11 , wherein the first planar surface is parallel to the second planar surface when the first planar surface (341) engages the second planar surface when the needle cover is in the holding position.

13. The medicament delivery device according to claim 8, wherein the engagement surface (341) comprises a curved surface.

14. The medicament delivery device according to any one of the preceding claims, wherein the device further comprises a locking mechanism (280) configured to lock the needle cover in a locking position, wherein in the locking position the needle cover (213, 613, 713) covers the needle (217).

15. The medicament delivery device according to claim 14, wherein the locking mechanism comprises a part of the detent mechanism (231, 331 , 431 , 531, 631 , 731).

16. The medicament delivery device according to any one of the preceding claims, wherein the detent mechanism (231, 331, 431, 531 , 631, 731) provides haptic feedback to the user when it is engaged in the holding position.

17. The medicament delivery device according to claim 4, or any one of claims 5 to 16 when dependent upon claim 4, wherein when the cooperating component comprises the aperture (240, 340, 640), at least a part of the flexible arm, such as a protrusion (232, 332, 432, 532, 632, 732), is visible through the aperture when the detent mechanism (231, 331, 631) is engaged.

18. The medicament delivery device according to any one of the preceding claims, wherein the device comprises the medicament.

19. The medicament delivery device according to any preceding claim, wherein the body is configured to be gripped by a user.

20. A method of using an injector device, wherein the injector device has the features according to any preceding claim.

21. A method of using an injector device, the method comprising the steps of pressing a needle cover (213, 613, 713) of the device against an injection site; applying a holding force to the device to hold the needle cover (213, 613, 713) against the injection site whilst medicament is dispensed from the device; and then removing the injector device from the injection site, wherein removing the injector device from the injection site comprises reducing the holding force until a spring force of a spring acting on the needle cover overcomes a resistance force of a detent mechanism of the device to move the needle cover axially to cover the needle.

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