Drug delivery assembly with double-dose prevention features

Abstract

The drug delivery assembly comprises a drug delivery device and a needle unit mountable thereon. The drug delivery device includes an operable spring-driven discharge mechanism for dispensing a certain amount of drug. The needle unit includes a shield on which a hub containing a needle is positioned, and the shield is axially movable relative to the hub between an extended position where the shield axially covers the distal end of the needle and a retracted position where the distal end of the needle protrudes from the shield. Shield locking means act when the shield moves from the retracted position to the extended position, and operable shield locking means prevent the shield from retracting. The shield is adapted to actuate the discharge mechanism actuating means when the shield moves from the extended position to the retracted position, thereby preventing double operation of the discharge mechanism to which the same needle unit is mounted.

Description

Technical Field

[0001] The present invention generally relates to spring-driven drug delivery assemblies of the multiple-use type and addresses the problem of reducing the risk that a user will inadvertently administer two doses instead of one dose.

Background Art

[0002] In the disclosure of the present invention, primarily, subcutaneous injection needles intended for use by patients for subcutaneous administration of fluid pharmaceutical formulations, for example, in the treatment of diabetes by delivery of insulin or GLP-1 type drugs, or in the treatment of growth disorders by delivery of growth hormone, are referred to, but these are merely exemplary uses of the present invention.

[0003] Drug delivery devices for self-administration of different liquid formulations currently exist in a variety of shapes and sizes. Some are adapted to connect to an infusion set, while others are connected to or integrated with a syringe needle. The latter type is called an injection device. Some are durable devices with a cartridge having a drug reservoir, and the cartridge can be replaced. On the other hand, there are also disposable devices that are discarded when the cartridge is empty. The disposable device can be either a multiple-dose device where the user can set the desired dose size before each injection, or a single-dose device that can only perform a single dose of a given size. The latter exists in so-called "shield activation", where the cannula is covered by a shield on the front of the device that releases the dose when pressed. Then, the cannula is only exposed to enter the skin when the user presses the device against the skin, thereby depressing the shield and releasing the dose. These injection devices are discarded after a single injection.

[0004] Fixed-dose devices are preferred by some users because they may feel hesitant about or be unable to operate a device that adjusts the correct dose each time. For example, when the device is used by children or the elderly, simplicity and ease of use are important to avoid user errors that could lead to over- or under-dosing. In other cases, the treatment regimen may prescribe a fixed dose of, for example, a GLP-1 type drug.

[0005] However, just as a large amount of waste is generated when used devices are discarded, the device itself accounts for a significant portion of the unit's cost. Therefore, it would be desirable to manufacture a fixed-dose device that can deliver multiple doses of a fixed volume.

[0006] US2012 / 0016315 describes a needle magazine for an injection pen, which houses multiple injection needles that can be continuously brought into an aligning starting position with a partition portion of a cartridge. The needle magazine may be provided as a separate component that is detachably attached to the injection pen and is thereby intended to replace a conventional cap. Alternatively, the needle magazine may be provided so as to be fixedly attached to the injection pen so that the pen and needle magazine form a disposable unit. However, the injection pen is not a fixed-dose device because the dose needs to be selected before injection.

[0007] In existing multi-dose devices, the motor consists of a spring that is wound up when adjusting the dose. One solution is to manufacture a standard multi-dose device in which the maximum dose size is limited and therefore only dial-up to a fixed dose size is possible. However, this presents the risk that the user will not dial up sufficiently and therefore receive a smaller dose than expected. This problem is solved and described in WO2020 / 089167 in which a ratchet tube is locked in the housing until the full dose is set. Another fixed-dose device is disclosed in WO 2019 / 091879, relating to an injector with a longitudinally displaceable dose tracker that provides automatic dose setting set by a pre-selected dose size.

[0008] An alternative fixed-dose device is disclosed in WO2018 / 007259 relating to an injection device for delivering a defined number of equal doses of a fluid substance. The disclosed injection device comprises a housing having a safety release mechanism and a drug delivery mechanism arranged along the longitudinal axis of the housing.

[0009] If the drive mechanism of a fixed-dose device is pre-compressed and the dose can only be delivered by activating the start button, there is a risk that the user may inadvertently administer two doses instead of one.

[0010] International Patent Application WO2021 / 122192 describes a pre-tensioned, multi-use fixed-dose device comprising a locking and reset mechanism for releasably locking an activated shield when the shield is rotated from an initial position in which the shield is axially locked at a first angular position to an activated position in which the shield is axially movable and locked to a connector. The connector is disposed to establish a connection between the shield and the drive tube. After activation, the connector is adapted to induce distal and rotational motion of the shield, thereby allowing the shield to automatically rotate back to the initial position in response to a drive element that releases a releasable lock between the connector and the activation.

[0011] Some pre-tensioned fixed-dose devices do not have an activation shield that is biased to rotate away from the activation position. Therefore, in some devices, the shield or activation button will return to the same angular position after dose activation and delivery. Thus, it is desirable to provide a double-dose prevention mechanism in the drug delivery device so that the activation shield or activation button returns to the same angular position after activation.

[0012] WO2021 / 165250 describes an injection device for dispensing a predetermined number of fixed doses. The doses are dispensed by releasing a pre-stretched torsion spring by moving the needle shield proximally, thereby dispensing one of the predetermined doses at a time. The injection device is further provided with several integrated needle assemblies that move to injection positions one at a time. The needle exchange mechanism that operates the needle assemblies is controlled by the rotation of a needle shield that is rotatable between a locked position and an unlocked position. Thus, the user can lock and unlock the injection device by rotating the needle shield when the needle shield is in its extended first position.

[0013] US 2013 / 0090604 and US 2014 / 0031760 disclose drug needle modules adapted for use in conjunction with conventional manually operated drug delivery devices, the latter comprising a first drug and the drug needle module comprising a second drug. The needle module comprises a spring-fed shielding member that locks into place after single use.

[0014] WO2018 / 215605 discloses a shielded needle unit in which the shield locks into place in its extended position after a single use. The needle unit comprises a proximal activator leg for interaction with a trigger mechanism in a drug delivery device to which it is attached. Similar arrangements are disclosed in WO2017 / 114894 and WO2017 / 114921.

[0015] If a given drug delivery device is designed such that the user must set the dose and compress the drive spring before delivering a new dose of the drug, a built-in fault is provided to prevent accidental double-acting of the device.

[0016] In relation to the above, an object of the present invention is to provide a pre-tensioned, multi-use type spring-driven drug delivery assembly that can reduce the risk of a user inadvertently administering two doses instead of one in a user-friendly and cost-effective manner. The spring-driven drug delivery assembly may be adapted to dispense a preset or user-defined amount of drug. [Overview of the Initiative]

[0017] The disclosure of the present invention describes embodiments and aspects that address one or more of the above-mentioned objectives, or objectives that are evident not only from the following disclosure but also from the description of exemplary embodiments.

[0018] Accordingly, in one aspect of the present invention, a drug delivery assembly is provided comprising a drug-filled cartridge and a drug delivery device comprising a needle unit mountable thereon or adapted to receive the cartridge. The drug delivery device comprises a housing; coupling means enabling the needle unit to be mounted on the drug delivery device; an operable discharge mechanism for discharging a pre-pulled or user-defined amount of drug from the cartridge; a drive spring for driving the discharge mechanism, the drive spring being pre-pulled in accordance with a predetermined dose or amount of drug; and an actuation means for operating the discharge mechanism. The needle unit comprises a needle hub; a hollow needle mounted within the needle hub and having a pointed distal end protruding from the needle hub, the hollow needle defining a reference axis; a shield on which the needle hub is fully or partially disposed, the shield being axially movable relative to the needle hub between an initial extended position in which the shield axially covers the distal end of the needle; a retracted position in which the distal end of the needle protrudes from the shield; and a final extended position in which the shield axially covers the distal end of the needle; a mounting coupling enabling the needle unit to be mounted on the drug delivery device; and a shield locking means that acts when the shield is moved from the retracted position to the extended position, the acting shield locking means preventing the shield from retracting. When the needle unit is mounted on the drug delivery device, the shield is adapted to actuate an ejection mechanism actuate when the shield moves from the extended position to the retracted position, thereby preventing double operation of the ejection mechanism to which the same needle unit is mounted. The prescribed number of doses is at least two, and the prescribed amount of medication corresponds to the amount of medication in a pre-installed medication cartridge, or to the amount of medication in a receivable cartridge, such as 1.5 or 3.0 ml.

[0019] In this way, although the actual mechanism for preventing double dosing does not form part of the drug delivery device itself, a simple double-dose prevention arrangement is provided for a pre-stretched spring-driven multi-dose drug delivery device, which is provided by the shield locking function of the needle unit, a function unique to shielded single-use needle units in which the shield can move back and forth only once. Since single-use shielded needle units essentially need to be replaced after each dosing event, no additional user involvement is required to provide the double-dose prevention feature.

[0020] In an exemplary embodiment, the mounting coupling is operable between a locked state in which the mounted needle unit cannot be removed from the drug delivery device and an activated release state in which the needle unit can be removed from the drug delivery device, and the mounting coupling is actuated from the locked state to the released state when the shield moves from its retracted position to its extended position.

[0021] This arrangement prevents users from accidentally removing and discarding unused needle units. If a needle unit cannot be removed from the drug delivery device, it is not in use. This further prevents users from removing and reinstalling unused needle units, thereby eliminating the risks associated with unnecessary handling of needle assemblies. In practice, the phrase "cannot be removed" should be interpreted as referring to the case when using "normal" force.

[0022] The shield may be mounted non-rotatably on the drug delivery device, so that the rotational movement of the needle hub inside the shield activates the mounting coupling from a locked state to a released state, and thus it can be hidden from the user.

[0023] In an alternative configuration, the final extended position of the shield is distal to the initial extended position of the shield, for example, as shown in the diagram opened in WO2018 / 215605 above, thereby allowing the mounting coupling means to be activated from the initial state to the operational state as the shield moves from the retracted position to the final extended position.

[0024] Alternatively, the shield may be rotatably mounted on the drug delivery device, which allows the rotational movement of the shield to actuate the mounting coupling from a locked state to a released state.

[0025] In exemplary embodiments, the mounting coupling comprises a flexible, for example, gripping finger adapted to grip a corresponding coupling structure on a drug delivery device, e.g., a circumferential flange, and a blocking means adapted to block the radial movement of the gripping finger corresponding to a locked state in which the mounted needle unit is not removed from the drug delivery device. The flexible gripping finger and the blocking means are movable relative to each other from a locked position corresponding to a locked state to a released position corresponding to a released state in which radial movement of the gripping finger is possible, thereby enabling the needle unit to be removed from the drug delivery device.

[0026] Flexible gripping fingers may form part of the needle hub, and blocking means may form part of the shield. The needle hub and shield are rotatable relative to each other; for example, the needle hub and shield may rotate relative to each other when the shield is moved from its retracted position to its extended position. In an alternative configuration, the blocking means may be moved axially to a released position when the shield returns to its most distal final position.

[0027] In an exemplary embodiment, the attachment coupling is further operable between, for example, an initial attachment state supplied to the user, in which the needle unit can be attached onto the drug delivery device, and a locked state. To achieve this function, the attachment coupling can be actuated from the attachment state to the locked state by an axial movement of the shield relative to the needle hub from a delivery position to an actuated position. The latter may be a configuration corresponding to an initial extended position. The shield may be axially moved by a biasing means included within the drug delivery device, such as a spring member, and such a biasing member also serves to return the shield to its final extended position after use.

[0028] As shown in the above drawings, the needle unit comprises an attachment coupling that enables the needle unit to be attached onto the drug delivery device. Correspondingly, the latter may comprise a cartridge mount, for example, as part of a cartridge holder, and enables the needle unit to be attached in fluid communication with the interior of the cartridge.

[0029] In further exemplary embodiments, the needle unit is provided in combination with a container adapted to accommodate a shield and a hub disposed therein, and the combination forms a needle assembly including a snap fit between the container and the shield. The snap fit is operable between a first state in which the needle unit can be removed from the container using a first amount of force and a second state in which the needle unit can be removed from the container using a second, higher amount of force. Note that the purpose of the second state is not to make it more difficult to remove the container, but rather to enable the container to be used as a pull assist to prevent the container and, therefore, remove the hub from the cartridge mount.

[0030] The container may comprise an open end adapted to be sealed with a flexible foil member, thereby providing a sealed and sterile interior for the needle assembly when supplied to the user.

[0031] The snap coupling may also be provided with cooperating first and second coupling means, each positioned on the shield of the container, wherein the first coupling means is operable between an initial state corresponding to a first state of the snap coupling and an activated state corresponding to a second state of the snap coupling, and the first coupling means is operable from the initial state to the activated state as the shield moves from its extended position to its retracted position and back to its extended position.

[0032] In one exemplary embodiment, the first coupling means includes a blocking means movable relative to the flexible shield snap structure from a non-blocking position that allows radial movement of the flexible shield snap structure corresponding to a first state to a blocked position that prevents radial movement of the flexible shield snap structure corresponding to the first state.

[0033] The blocking means may be configured to form part of the needle hub such that the needle hub and the shield rotate relative to each other as the shield moves from its retracted position to its extended position, and the first coupling means operates from an initial state to an operating state as the needle hub rotates relative to the shield from an initial position to an operating position.

[0034] In all of the embodiments described above, the hollow needle may have a pointed proximal end adapted to be inserted through a needle-penetrating cartridge partition to provide fluid communication between the inside of the cartridge and the distal end exit opening of the needle when the needle unit is mounted on a drug delivery device. To reduce the risk of accidental needle stick injuries, the proximal needle end may be located distal to the nearest portion of the needle hub and / or shield, i.e., the distal needle end is located inside the needle unit.

[0035] As used herein, the term “drug” means any drug-containing fluid pharmaceutical that can pass through a delivery means such as a subcutaneous injection needle in a controlled manner, such as a liquid, solution, gel, or microsuspension. Drugs may have blood glucose-controlling effects, such as human insulin and its analogues, as well as non-insulinic effects such as GLP-1 and its analogues. [Brief explanation of the drawing]

[0036] Embodiments of the present invention will be described below with reference to the drawings.

[0037] [Figure 1] Figure 1 shows the components of an exemplary first embodiment of a needle assembly comprising a shield member, a hub member, and a container. [Figure 2] Figure 2 shows a cross-sectional view of the assembled needle assembly from Figure 1, which has a needle unit formed by a shield member and a hub member attached to a container. [Figure 3] Figure 3 shows an alternative embodiment of the needle unit attached to a pen-type device. [Figure 4] Figures 4A and 4B show the shield member of Figure 1 viewed from the proximal end and the distal end, respectively. Figure 4C shows the shield member of Figure 4A in cross-sectional view. [Figure 5] Figures 5A and 5B show the hub member of Figure 1 as viewed from the proximal end and the distal end, respectively. [Figure 6] Figures 6A and 6B show the container of Figure 1 viewed from the proximal end and the distal end, respectively. Figure 6C is a cross-sectional view showing the shield member of Figure 6B. [Figure 7] Figure 7 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 8] Figure 8 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 9] Figure 9 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 10] Figure 10 shows cross-sectional views of the stylus assembly from Figure 1 in different states mounted on the cartridge mount. [Figure 11] Figure 11 shows cross-sectional views of the needle unit of Figure 1 in different states during operation. [Figure 12]Figure 12 shows cross-sectional views of the needle unit from Figure 1 in different states during operation. [Figure 13] Figure 13 shows that the outer portion of the shielding member has cut through the needle unit in Figure 14. [Figure 14] Figure 14 shows cross-sectional views of the needle unit in Figure 1 in different states during operation. [Figure 15] Figure 15 shows a detailed cross-sectional view of the shield locking mechanism. [Figure 16] Figure 16 shows cross-sectional views of the stylus assembly from Figure 1 in different states after being removed from the cartridge mount. [Figure 17] Figure 17 shows a cross-sectional view of the stylus assembly from Figure 1 in a different state after it has been removed from the cartridge mount. [Figure 18] Figure 18 shows a cross-sectional view of the stylus assembly from Figure 1 in a different state after it has been removed from the cartridge mount. [Figure 19] Figure 19 shows an alternative embodiment of a cartridge mount used in combination with the needle unit of Figure 1. [Figure 20] Figure 20 shows a second embodiment of a drug delivery device having an attached needle unit. [Figure 21] Figure 21 shows a cross-sectional view of drug delivery device 1 with the needle unit replaced with a cap. [Figure 22] Figure 22 shows an exploded view of the components of the drug delivery assembly shown in Figures 20 and 21. [Figure 23] Figures 23A and 23B show a perspective view and a cross-sectional view, respectively, of the shield member shown in Figure 22. [Figure 24] Figures 24A and 24B show a perspective view and a cross-sectional view, respectively, of the hub member shown in Figure 22. [Figure 25] Figures 25A and 25B show a perspective view and a cross-sectional view, respectively, of the container for the needle unit shown in Figure 20. [Figure 26] Figure 26 shows a cross-sectional view of the needle unit from Figure 20, which is placed inside the container from Figure 25A. [Figure 27]Figures 27A–27J show a series of cross-sectional views illustrating the installation, operation, and removal of the needle unit on the drug delivery device. Figures 27CX and 27GX show cutaway views of the corresponding Figures 27C and 27G. [Figure 28] Figures 28A-28C show a series of cutaway perspective views illustrating the movement of the shield and needle hub relative to the housing indicator opening during operation of the needle unit.

[0038] In these diagrams, similar structures are primarily identified by similar reference numbers. [Modes for carrying out the invention]

[0039] Where terms such as “up” and “down,” “right” and “left,” “horizontal” and “vertical,” or similar relative expressions are used below, they simply refer to the accompanying diagrams and do not necessarily represent actual usage. The term “distal” refers to an element, assembly, or part of a device that is oriented toward the user’s skin surface during use, and the term “proximal” refers to the opposing part. Accordingly, in conventional pen-type drug delivery devices, the needle is located at the distal end, and the release button attached to the end is located at the proximal end. The diagrams shown are schematic and are therefore intended for illustrative purposes only, as are the configurations of different structures as well as their relative dimensions. Where the term member or element is used for a given component, this generally indicates that in the described embodiment, this component is a single component; however, two or more of the described components may be provided as a single component, for example, manufactured as a single injection-molded part, and alternatively, the same member or element may comprise several subcomponents. The term “assembly” is not intended to imply that the described components are necessarily assembled to provide a single, functional assembly during a given assembly procedure, but is simply used to describe components that are classified together as being more closely related functionally.

[0040] Referring to Figures 1 and 2, a first embodiment of the shielded needle assembly 2 is shown, which comprises a needle hub 100 adapted to be mounted on a corresponding needle attachment on a drug delivery device; a subcutaneous injection hollow needle 101 attached to the hub and having a pointed free distal end portion adapted to be inserted subcutaneously through the user's skin and a pointed free proximal end portion adapted to penetrate a puncturable drug cartridge partition; a shield member 200 on which the needle hub is placed; and a container 280. The needle hub, with the attached needle and shield member, combines to form the needle unit 1. The subcutaneous injection hollow needle 101 has chamfered proximal and distal ends and is positioned within the hub hole and secured in place, for example, by adhesive. The container 280 is adapted to receive the needle unit and thereby form the needle assembly, and the container has an open end adapted to be sealed with a flexible foil member, thereby providing a sealed sterile interior to the needle unit 2 when supplied to the user. In the illustrated embodiment, the proximal end of the needle extends proximal to the nearest portion of the hub, but not proximal to the nearest portion of the shield, which reduces the risk of accidental needle contact.

[0041] Figure 3 shows a needle unit 11 mounted on an injection device 3 adapted to detachably receive the needle unit. In contrast to the circular configurations of the needle units in Figures 1 and 2, Figure 3 shows an exemplary design having an outer square configuration that allows the shield 302 to be received within a correspondingly formed distal cartridge portion 402 of the injection device 3. Alternatively, other non-circular designs, such as oval or triangular, can be implemented. As will be apparent from the following detailed description of exemplary embodiments of the needle assembly, the function of the assembly depends on rotational movement between the hub and the shield, regardless of the outer configuration of the shield.

[0042] As will be described in more detail below, the needle hub 100 (hereinafter also simply referred to as the "hub" or "hub member") and the shield member 200 (hereinafter also simply referred to as the "shield") have several interaction structures that enable the shield and the hub to move axially and rotatably relative to each other in a controlled manner during use and operation of the needle unit. In the embodiments described below, the shield is rotatably locked to the cartridge mount, and the hub is axially locked to the cartridge mount when the needle unit is mounted on the cartridge mount. The rotational movement of the hub is controlled by the axial movement of the shield relative to the cartridge mount and, consequently, to the hub.

[0043] Furthermore, as will be described in more detail below, the container and shield member include several interaction structures that enable the container to be used as an attachment and removal tool for the needle unit during use in an efficient and user-friendly manner. The shield, hub, and container generally have opposing pairs of functional structures, but any preferred number of such structures, e.g., one, two, or three, can be used. The structure and functionality of the needle unit and container will be described with reference to embodiments having a generally circular configuration of the shield and container (see Figures 1, 2, and 4A-18), however the shield and container may have a non-circular configuration, such as shown in Figure 3, where the shield 302 and the drug delivery device housing 402 have a wrinkled configuration.

[0044] As shown in Figures 4A-4C, the shield 200 has a generally tubular configuration, having a circumferential outer wall 210, a proximal skirt portion 202 with a proximal opening having a circumferential edge 211, and a distal end surface 201 with a smaller distal opening 212 from which the tower structure protrudes axially inward. In the illustrated embodiment, the tower structure includes first and second pairs of opposing arms offset by 90 degrees. The first pair of arms are in the form of flexible stop arms 220, each having a distally facing axial stop surface 221 at a proximal free end adapted to engage with a corresponding proximal-facing stop surface on the hub tower portion (see below), and a proximal-facing inclined surface 222 used during the assembly of the needle assembly. The second pair of arms are in the form of flexible control arms 230, each having a proximal-facing inclined surface 231 and a distal-facing control surface 232 at its proximal free end, the surfaces being adapted to engage with the corresponding distal-facing inclined surface and proximal-facing control surface on the hub tower portion, respectively (see below). At the proximal end, the shield comprises a pair of opposing inner block surfaces 213 adapted to engage with the corresponding flexible hub arm (see below). The shield further comprises a pair of opposing locking ribs 214 on the inner wall surface of the shield, each rib having a proximal-facing locking surface 215 adapted to engage with the corresponding locking surface on the hub. The outer wall 210 of the shield is further provided with a pair of opposing flexible coupling arms 240, each arm comprising an inner ridge 241 and an outer ridge 246 at its distal free end, adapted to engage with the corresponding structure on the hub and the container, respectively (see below).

[0045] As shown in Figures 5A and 5B, the hub 100 comprises a distal tower portion 110 having a central hole adapted to receive a subcutaneous injection needle and a proximal skirt portion 120. At the distal end, the tower portion includes three pairs of opposing functional surfaces adapted to cooperate with corresponding surfaces on the shield: a pair of proximal-facing stop surfaces 121 adapted to engage with a distal-facing stop surface 221 on the shield; a pair of distal-facing inclined surfaces 131 adapted to engage with a proximal-facing inclined surface 231 on the shield; and a pair of inclined proximal-facing control surfaces 132 adapted to engage with a distal-facing control surface 232 on the shield during operation. The hub tower further carries a pair of opposing axially extending block flanges 140, each having an outer block edge 141 adapted to engage with a corresponding inner ridge 241 of the shield coupling arm during operation. The skirt portion 120 comprises a disc portion having two opposing part circumferential bearing surfaces 125 that extend proximal and are adapted to engage with a corresponding bearing structure on the shield to ensure stability during axial and rotational movement between the hub and the shield during operation. The skirt portion comprises a pair of opposing proximal-extending flexible coupling arms 126, each having an outer surface 113 adapted to engage with the inner block surface 213 of the shield during operation; an inward-facing snap coupling ridge 127 located at the free proximal end of the coupling arm and adapted to engage with a corresponding coupling structure on the cartridge mount; and a distal-facing locking surface 115 adapted to engage with the proximal-facing shield locking surface 215 during operation.

[0046] As shown in Figures 6A-6C, the container 280 has a generally tubular configuration, having an outer peripheral wall 281, a proximal opening with an outer peripheral flange 282, and a closed distal end 283 from which a tower structure 285 projects axially inward. The container has a stepped configuration with a distal portion of a smaller diameter and a proximal portion of a larger diameter. An inner circumferential ridge structure 286 is positioned between the two portions and is adapted to engage with an outer ridge 246 on the shield flexible coupling arm 240. The remainder of the circumferential ridge functions to support the shield when it is placed inside the container. With the shield installed inside the container, the larger diameter proximal portion provides a circumferential space 299 (see Figure 2) between the container and the shield, allowing the correspondingly shaped drug delivery housing portion to be received therein during the attachment of the needle assembly to the drug delivery device.

[0047] During assembly, a hollow subcutaneous injection needle having inclined proximal and distal ends is placed in the hub hole and fixed in place, for example, by adhesive, thereby providing a free distal end 102 and a free proximal end 103. The hub is then inserted into a shield having stop surfaces 121 and inclined surfaces 131, which are rotatably aligned with the shield stop surface 221 and shield inclined surface 231, respectively, thereby allowing the shield stop surface to snap into engagement with the hub stop surface 121. The hub coupling arm 126 is also rotatably aligned with the shield block surface 213. The assembled needle unit is then inserted into the container by snapping the container rim 286 into engagement with the outer ridge 246 on the shield flexible coupling arm 240. As shown in Figure 2, the container tower 285 abuts against the distal end of the hub tower. In the final assembly step, a flexible foil member is attached to the proximal flange 282 of the container, thereby sealing the interior for subsequent sterilization.

[0048] The following describes the different features and embodiments of the above-mentioned needle unit and container combinations with reference to Figures 7-18, which show needle units mounted on a corresponding drug delivery device, operating to allow a certain amount of fluid drug to be subcutaneously injected and then removed from the drug delivery device.

[0049] After the flexible seal foil is removed from the container 280 by the user, the container can be used as a tool for mounting the needle unit onto the drug delivery device 13 having a corresponding cartridge mount 310. See Figure 7. The drug-filled cartridge 390, having a partition 394, is placed within the cartridge holder 300. In the illustrated embodiment, the cartridge mount is located proximal to the distal end of the drug delivery device housing 402, which has a circumferential space 403 between the cartridge holder 300 and the housing, adapted to receive the proximal portion of the shield in a non-rotational engagement, for example, by cooperating splines or a non-circular shape such as elliptical or square. Such a non-circular design also facilitates the user in rotatably oriented the needle assembly correctly relative to the drug delivery device. As shown in Figure 7, the hub coupling is in an initial mounting state in which the shield block surface 213 does not engage with the outer surface 113 of the flexible hub arm.

[0050] The container ensures that the shield can be firmly pressed by the user to engage with the cartridge mount, thereby allowing the free proximal needle end 103 to penetrate the cartridge partition 394, and the flexible hub coupling arm 126 to move radially outward within the receiving space on the shield and then snap radially inward to engage with the corresponding snap coupling means 311 on the cartridge mount. See Figure 8. In the illustrated embodiment, the drug delivery device is provided with a pair of opposing spring-biased connector members 502, which are initially pressed proximal by the shield periphery 211 over a short distance. During installation, the spline connection between the hub and the shield prevents rotational movement between them.

[0051] When the user stops pushing the container (or begins to pull the container away), the spring-biased connector member 502 pushes the shield 200 slightly distally until the distally facing axial stop surface 221 on the shield tower engages with the corresponding proximal-facing stop surface 121 on the hub tower portion. As the shield moves distally, the shield block surface 213 engages with the flexible hub arm outer surface 113 and moves, thereby preventing its radially outward movement. This securely locks the hub 100 to the cartridge mount 310, corresponding to an operating hub coupling lock state that prevents the mounted needle unit from being removed from the drug delivery device. See Figure 9.

[0052] When the user pulls the container 280 further distally to completely remove it, the container snap coupling ridge engages and disengages the shield 200. In the illustrated embodiment, the shield comprises a pair of flexible coupling arms 240, each having a ridge 246 facing outward at its free end, which is pushed inward by the container snap coupling ridge 286, thereby allowing the container to be easily moved distally. See Figure 10. Once the container is completely removed, the drug delivery device with the attached needle unit 1 becomes usable, as shown in Figure 11. Note that the cross-sectional views in Figures 10-12 are rotated 90 degrees compared to Figures 7-9, so that the inclined surface 231 on the shield flexible control arm 230 can be seen as stationarily engaged with the distally facing inclined surface 131 on the hub tower. Furthermore, due to the rotation, the connector 502 that engages with the proximal end 211 of the shield is not visible. In this state, the shield is in its initial extended position.

[0053] When the user pushes the needle unit toward the skin surface, the shield 200 is pushed proximal, allowing the distal end of the needle 102 to be inserted subcutaneously. During the initial proximal movement of the shield, the inclined surface 231 on the flexible control arm 230 is pressed against the hub tower inclined surface 131. As the shield moves further proximal to its fully retracted position, the distal end of the needle protrudes from the shield corresponding to the needleless length portion 104 (see Figure 12). Simultaneously, the proximal periphery 211 of the shield pushes a pair of connector members 502 proximal (see Figure 9), thereby releasing the drug delivery device discharge mechanism and thereby initiating subcutaneous injection. As shown, the connector members 502 function as both a locking actuator for the hub coupling and a release member for the discharge mechanism. Drug delivery devices having similar release connectors adapted to transmit translational movement from a retractable needle shield to an ejection mechanism are disclosed in WO2021 / 122219 and WO2021 / 122192 and are suitable for adaptation to function with the present needle unit. Alternatively, the ejection mechanism may be released by a manually operated release means on the drug delivery device, such as a proximal push button. Such a push button may be configured to be blocked for operation until released by the proximal movement of the shield.

[0054] After the dose has been completely dispensed, the user withdraws the needle unit from the skin surface, thereby allowing the spring-biased connector 502 to move distally to its fully extended final position, which again covers the distal portion of the needle 102. During this movement, a control surface 232 on the shield control arm 230 (see Figure 4C) engages with an inclined proximal-facing control surface 132 on the hub tower, which rotates the needle hub 100 when the shield is rotatably locked to the drug delivery device. See Figure 13. In the illustrated embodiment, the hub is rotated 45 degrees relative to the shield. In the illustrated embodiment, the initial and final extended positions of the shield relative to the hub are the same.

[0055] During the rotation of the hub 100 relative to the shield 200, several structures engage with each other and move in and out. Note that the cross-sectional views in Figures 16 and 17 below are rotated 90 degrees compared to Figures 14 and 18, which allows us to show the cooperation between the hub block flange edge 141 and the inner ridge 241 of the shield flexible coupling arm.

[0056] (i) When the hub rotates, the flexible hub coupling arm 126 disengages from the shield block surface 213 and rotates, thereby allowing the flexible hub arm to move radially outward. See Figure 14. Thus, the hub 100 is removed from the cartridge mount 310.

[0057] (ii) Once the needle 101 is fixed within the hub 100, the needle will rotate with the rotating hub, but it is not always desirable for the needle to rotate when it is fully inserted subcutaneously. Accordingly, the hub and shield can be designed with axial slack or "play" before the shield control surface 232 engages with the inclined hub control surface 132, which allows the needle to be withdrawn at least partially from the skin before rotation begins. In fact, subsequent rotation should begin with a more abrupt inclination of the hub control surface, and the inclination of the hub control surface should be abrupt.

[0058] (iii) Before the needle unit begins to operate, a pair of locking ribs 214 on the inner surface of the shield move freely in the axial direction, thereby allowing the shield to move from its extended position to its retracted position. As the hub rotates, a pair of distally facing locking surfaces 115 rotate to align with the proximal ends 215 of the locking ribs 214, thereby preventing repeated retraction of the shield and consequently the use of the needle unit, and thereby providing a safety lock. See Figure 15. Accordingly, the locking surfaces should be designed to withstand relatively large forces to prevent the needle unit from restarting, for example, if the pen-type device falls onto a solid surface or in misuse scenarios. Furthermore, if the drug delivery device is shield released, the shield lock also functions as a double dose prevention means.

[0059] (iv) As the hub 100 rotates, a pair of block flange edges 141 rotate to align with the inner ridge 241 of the shield flexible coupling arm, thereby preventing the arm from bending inward. In this state, the actuating needle unit and the locking needle unit can be removed from the cartridge mount by simply grasping and pulling the shield distally (the shield is axially connected to the hub via corresponding stop surfaces 221, 121 on the shield tower and hub tower, respectively; see Figure 14), however, in the illustrated embodiment, the container is also intended to be used as a tool for removing the needle unit; see Figure 16. More specifically, with the shield flexible coupling arm 240 in a blocked state, the container 280 is mounted on the shield by a user applying axial force until the container snap coupling ridge 286 overrides the shield outer ridge 246, for example by ellipsing the container wall; see Figure 17. The container snap coupling is designed to have a release force greater than the release force required to axially separate the flexible hub coupling arm 126 from its engagement with the cartridge mount 310, thereby allowing the needle unit to be removed from the cartridge mount, which is then securely held in the container for safe disposal. See Figure 18. Because the needle unit is locked to the container via the container snap coupling, and its proximal end is positioned at a specific distance inside the container and surrounded only by a small amount of free space, removing the needle unit from the container is difficult for the user.

[0060] Alternative embodiments: As the hub rotates relative to the cartridge mount, this characteristic can be utilized to provide a cartridge mount 360 having different snap coupling characteristics depending on the rotational position of the hub relative to the cartridge mount. More specifically, as shown in Figure 19, the cartridge mount is provided with a first set of snap coupling structures 361 adapted to engage with the hub snap coupling structure to allow the hub to be mounted using a first amount of force, and a second set of snap coupling structures 362 adapted to engage with the hub snap coupling structure to allow the hub to be removed using a second, lower amount of force, wherein the first and second cartridge mount snap coupling structures may be configured to be rotationally offset from each other, for example, by 45 degrees. A given coupling force may be provided, for example, by the inclination of the coupling inclined surface.

[0061] As an alternative to the shield's flexible coupling arm, the shield's outer wall may be provided with a thin wall section that supports a snap projection, allowing the snap projection to bend inward when not blocked by the hub. Such a design provides a cleaner appearance and prevents the potential intrusion of materials that could interfere with the shielding mechanism.

[0062] As a further alternative, the shield coupling may be provided with one or more radially movable shield snap structures, and the container coupling means comprises corresponding container snap structures adapted to engage with the shield snap structures. Such radially movable shield snap structures may be located on a thin-walled shield portion or on a flexible finger structure. The shield coupling means includes an actuation means that is movable with respect to the radially movable shield snap structure from an unengaged position corresponding to a first state to an engaged position in which the shield snap structure is moved radially outward corresponding to a second state. The actuation means may be configured to correspond to the flange 141 described above. As shown, a stronger snap coupling may be provided, for example, by making the shield coupling structure stiffer or projecting further outward.

[0063] As a further alternative configuration, the block mechanism for the shield-container coupling may be dispensed, meaning the hub may not have a structure that engages with the shield-container coupling during operation. In this way, the forces required for removing, attaching, and preventing the container from being removed from the shield during operation are provided solely by the design of cooperating surfaces, such as the inclination of an inclined surface.

[0064] Where a rotating needle hub is desirable, the configuration may include additional components to achieve secure locking in a similar manner. More specifically, the needle unit may be configured to include a hub and a shield coupled to each other to allow only axial movement, the assembly comprising a locking ring rotated by the forward and backward axial movement of the shield relative to the hub during operation, and the components comprising cooperating control surfaces adapted to rotate the locking ring from a non-blocking position to a blocked position as the shield returns from its retracted position to its extended position.

[0065] In a further alternative configuration, the final extended position of the shield is distal to the initial extended position of the shield, which allows the shield coupling means to be activated from the initial state to the operational state as the shield moves from the retracted position to the final extended position.

[0066] A similar arrangement is used in the shielded needle assembly disclosed in WO2018 / 215605 above, where the shield is returned to its most distal final position, allowing the container to snap-engage with the shield. If the coupling operation is based on hub rotation, the initial and final extended positions of the shield relative to the hub will typically be the same.

[0067] In a further alternative configuration, the needle assembly is provided with a snap coupling including cooperating first and second coupling means disposed on the shield and the container, respectively, such that, as described above, the container coupling means is operable between an initial state corresponding to a first state of the snap coupling and an activated state corresponding to a second state of the snap coupling. The container coupling means may be configured to be activated from the initial state to the activated state when the container, which is in a first rotational position relative to the shield, is removed from the shield and then reattached to the shield, which is in a second rotational position. As shown, in such a simplified arrangement, the operation of the snap coupling involves active manipulation of the shield by the user. To ensure the correct orientation of the container in use, the container and shield (or drug delivery device) may be provided with corresponding markings.

[0068] In certain embodiments, the second coupling means comprises first and second coupling structures, the first coupling structure being adapted to engage with the first coupling means when the container is in a first rotational position relative to the shield, and the second coupling structure being adapted to engage with the first coupling means when the container is in a second rotational position relative to the shield. The coupling structures may take the form of a somewhat "aggressive" snap structure that engages with the shield.

[0069] Further embodiments of the shielded needle assembly will be described with reference to Figure 20-28C.

[0070] Referring to Figure 20, a drug delivery device 1003 having a mounted needle unit 1001 is shown. The device preferably has a generally tubular configuration defining a common reference axis. Figure 21 shows a cross-sectional view of the drug delivery device 1003 having a cap and a replaceable needle unit. In the illustrated embodiment, the cap fits snugly onto the distal portion of the drug delivery device and therefore does not allow the needle unit to be mounted simultaneously. The drug delivery device comprises a distal cartridge holder portion 1004 in which a drug-filled cartridge is arranged, a proximal portion comprising a drive spring system 1005, and an intermediate portion comprising a control system 1006. A piston rod is axially positioned within the device and is adapted to be moved distally by a drive spring to discharge a certain amount of fluid drug through the mounted needle unit, the amount of axial movement of the piston rod being controlled by the control system. In Figure 21, the actuator return spring is not shown.

[0071] The exploded view in Figure 22 shows the individual components of the drug delivery device and needle unit. The drug delivery device comprises a tubular housing 1400 having a proximal engine portion 1401 and a distal cartridge portion 1402 adapted to house a cartridge holder 1300 in which a drug cartridge 1390 is arranged, the drug cartridge having a needle-punctureable partition, a proximal circumferential edge, and a distal outlet end having an axially displaceable piston. A piston washer 1395 is disposed within the cartridge and engages with the proximal surface of the piston. The actuator 1500 comprises a cylindrical proximal portion 1501 from which a pair of legs 1502 extend distally between the housing and the cartridge holder. A drive nut 1600 is mounted within the housing and adapted to receive a piston rod 1650 by screw engagement. A piston rod is non-rotatably received within the distal tubular portion 1802 of a drive member 1800, which is adapted to be rotationally driven by a pre-stretched drive spring 1890 disposed within the proximal portion 1801 of the drive member, the proximal end of which is fixed to the housing via a spring base 1900. A control member 1700 is spline-engaged with the tubular portion 1802 of the drive member and is adapted to move axially in and out of engagement with the housing, thereby controlling the rotation of the drive member. A large-diameter return spring 1590 is configured to provide a distally directed biasing force on the actuator. The drug delivery device is adapted to receive a needle unit at its distal end, the needle unit comprising a needle hub 1100 having a needle 1101, and a shield member 200 in which the needle hub is placed. If the needle unit is not mounted on the drug delivery device, a cap 1490 may be mounted to cover the cartridge portion 1402.

[0072] A detailed description of the drug delivery device itself is disclosed in EP 23212595.5, which is incorporated herein by reference. Below, only those parts of drug delivery that directly engage with the needle unit are described.

[0073] As shown in Figures 23A and 23B, the shield 1200 has a generally tubular configuration, having a circumferential outer wall 1210 with a proximal skirt portion 1202, a proximal opening with a circumferential edge 1211, and a distal end face 1201 with a smaller distal opening 1212 from which the tower structure protrudes axially inward. The outer wall, and therefore the proximal skirt portion, also have a circumferential noncircular configuration in the form of a hyperelliptical cross-section in the illustrated embodiment. The tower structure, in the illustrated embodiment, includes a circumferential skirt portion 1215 that extends proximal to first and second pairs of opposing arms with a 90-degree rotational offset. Between the arms, the skirt portion includes a free-gripping edge portion 1216. The first pair of longer arms are in the form of flexible assembly arms 1220, each having a hook portion 1225 at the proximal free end, and a distally facing axial stop surface 1221 adapted to engage with a corresponding proximal facing stop surface 1121 on the hub tower portion (see below), as well as a proximal facing inclined surface 1222 used during assembly of the needle unit. The second pair of shorter arms are in the form of flexible control arms 1230, each having a hook portion 1235 at the proximal free end, and a proximal facing inclined surface 1231 and a distal facing control surface 1232, respectively, the surfaces adapted to engage with the corresponding distal facing inclined surface and proximal facing control surface on the hub tower portion (see below). At the proximal end, the shield comprises a pair of opposing inner operating ribs 1213 adapted to engage with the corresponding flexible hub arm (see below). The actuation rib 1213 also engages the coupling arm (see below) and positions the substantially circular hub at the center of the hyperelliptical shield, thus ensuring stability during axial and rotational movement between the hub and the shield in operation. The shield further comprises a pair of opposing locking ribs 1217 on the inner wall surface of the shield, each rib having a proximal-facing locking surface 1218 adapted to engage with a corresponding locking surface on the hub. The locking ribs proximal to a lower torque rib 1219 adapted to engage with a torque flange on the hub (see below).The shield wall 1210 further comprises an outer pair of opposing mounting ribs 1245 adapted to engage with a corresponding shield slot 1415 in the housing, a pair of opposing windows 1240 adapted to allow outward movement of a hub coupling arm (see below), and a first indicator opening 1241 and a second indicator opening 1246. In the illustrated embodiment, the first indicator opening 1241 is “open” for design reasons, but the shield edge 1211 has a cutout for structures within the drug delivery device. In the illustrated embodiment, a further pair of opposing guide structures 1247 (see Figure 27A) adapted to engage with a corresponding shield guide 1417 in the housing are provided distal to the indicator opening 1246.

[0074] As shown in Figures 24A and 24B, the hub 1100 includes a distal tower portion 1110 having a central hole 1111 adapted to receive a subcutaneous injection needle and a proximal skirt portion 1120. At the distal end, the tower portion has three pairs of opposing functional surfaces adapted to cooperate with corresponding surfaces on the shield: (i) a pair of proximal-facing stop surfaces 1121 adapted to engage with a distal-facing stop surface 1221 on the shield assembly arm; (ii) a pair of distal-facing inclined surfaces 1131 adapted to engage with a proximal-facing inclined surface 1231 on the shield; and (iii) a pair of inclined proximal-facing control surfaces 1132 adapted to engage with a distal-facing control surface 232 on the shield during operation. At the proximal end, the tower portion includes a pair of opposing snap recesses 1135 adapted to engage with a control arm hook portion 1235. The skirt portion 1120 comprises a pair of opposing flexible coupling arms 1126 extending proximal, each arm having an outer surface 123 adapted to engage with the shield's inner operating rib 1213 during operation, and an inwardly facing snap coupling ridge 1127 located at the free proximal end of the coupling arm and adapted to engage with the corresponding coupling structure on the cartridge mount 1310. The skirt portion further comprises a pair of distally facing locking surfaces 1118 adapted to engage with the proximal facing shield locking surface 1218 during operation. In the illustrated embodiment, the skirt portion further comprises a pair of radially projecting opposing drop locking release flanges 1114 adapted to engage with the corresponding actuator leg release surface 1524 (Figure 27CX), a pair of radially projecting opposing torque flanges 1119 adapted to engage with the shield torque rib 1219, and a pair of opposing indicator cutouts 1115. The torque interface may also be located on other parts of the shield and hub, for example, between the assembly arm and the hub tower section.

[0075] As shown in Figures 25A and 25B, the container 1280 has a generally tubular configuration, having a hyperelliptical outer wall 1281 corresponding to the hyperelliptical outer wall of the shield, a proximal opening with a circumferential flange 1282, and a closed distal end 1283 with a tower structure 1285 and a pair of opposing snap-locking fingers 1290 extending axially inward. Each snap-locking finger has an outwardly oriented snap projection 1296 adapted to removably engage with a shield tower grip edge portion 1216 to provide a snap connection. The container further includes a plurality of internal support ribs 1286 adapted to engage with the outer surface of the shield and support the shield when placed inside the container. With the shield installed inside the container, the proximal portion provides a circumferential space 1299 (see Figure 26) between the container and the shield, allowing a drug delivery housing portion of the corresponding shape to be received therein during the attachment of a needle unit to a drug delivery device.

[0076] During the assembly of the hollow subcutaneous injection needle 1101, which has inclined proximal and distal ends, it is positioned within the hub hole and fixed in place, for example, by adhesive, thereby providing a free distal end portion 1102 and a free proximal end portion 1103. In the illustrated embodiment, the needle proximal end portion extends proximal to the tower portion 1110 but not proximal to the nearest portion of the hub 1100, which reduces the risk of accidental needle contact. The hub 1100 is then inserted into the shield 200, which has stop surfaces 1121 and inclined surfaces 1131, respectively, which are rotatably aligned with the shield stop surface 1221 and the shield inclined surface 1231, thereby allowing the shield stop surface to snap into engagement with the hub stop surface 1121. The hub coupling arm 1126 is also rotatably aligned with the shield operating rib 1213. In the illustrated embodiment, the hub proximal end is positioned slightly proximal to the shield proximal edge 1211. Next, the assembled needle unit is inserted into the container by snapping the container snap locking finger 1290 into the shield tower grip edge portion 1216, thereby forming the needle assembly. As shown in Figure 26, an axial gap is provided between the proximal end of the container tower and the distal end of the hub tower. In the final assembly step, a flexible foil member (not shown) is attached to the proximal flange 1282 of the container, thereby sealing the interior for subsequent sterilization. Figure 26 shows a cross-section of the needle assembly 1002 with the needle unit 1001 positioned inside the container 1280 before the sealing foil is attached.

[0077] The following describes the different features and embodiments of the above-mentioned needle unit and container combinations with reference to Figures 27A-27J. Figure 27A-27J shows a needle unit mounted on a corresponding drug delivery device that operates to allow a certain amount of fluid drug to be subcutaneously injected and then removed from the drug delivery device. The indicator function is further illustrated in Figure 28A-28C.

[0078] After the flexible seal foil is removed from the container 1280 by the user, the container is intended to be used as a tool for mounting the needle unit onto the drug delivery device 1001 having a corresponding cartridge mount 1310. See Figure 27A. In the illustrated embodiment, the cartridge mount is positioned proximal to the distal end of the drug delivery device housing cartridge portion 1402, having a circumferential space 1403 between the cartridge holder 1300 and the housing, which is adapted to receive the proximal portion of the shield 1200 in non-rotational engagement by cooperating mounting ribs 1245 and shield slots 1415. In the illustrated embodiment, the non-circular hyperelliptical design of the container, shield, housing outer surface, and inner circumferential space facilitates the user in orienting the needle assembly rotationally correct relative to the drug delivery device in either of its two possible rotational positions.

[0079] Alternatively, the non-circular configuration of the shield, container, and housing may be an asymmetrical form providing one rotational mounting position, an elliptical, oval, or rectangular form providing two rotational mounting positions, a triangular form providing three rotational mounting positions, or a square form providing four rotational mounting positions.

[0080] First, the locked hub coupling arm 1126 engages with the cartridge mount coupling flange portion 1311, thereby allowing the container to push the shield forward in an axial position where the shield operating rib 1213 does not engage with the outer surface 123 of the flexible hub arm. See Figure 27B. The control arm 1230 bends freely outward to allow proximal shield movement, but does not snap onto the inclined surface 1131. Note that in Figure 27B, the two structures are shown superimposed for drawing purposes. Alternatively, a configuration with a gap between the two structures may be used.

[0081] The container ensures that the shield and hub can be firmly pressed by the user to engage with the cartridge mount, thereby allowing the free proximal needle end portion 1103 to penetrate the cartridge partition 1394 and the flexible hub coupling arm 1126 to first move radially outward within the receiving shield window 1240 and then snap inward to engage with the corresponding snap coupling flange 1311 on the cartridge mount. See Figure 27C.

[0082] During the axial coupling movement of the needle unit, the hub drop locking release flange 1114 engages with an inclined leg release surface 1524 on the spring-biased actuator leg 1502. Initially, the actuator is moved axially until the anti-rotation clutch portion 1517 disengages from the housing and moves, thereby allowing the actuator to rotate by the axial movement of the hub. To counteract the torque applied to the hub during the rotation of the actuator, the hub is supported by a shield (non-rotatably coupled to the housing 1400) via a torque flange 1119 that engages with a torque rib 1219. Subsequently, the shield actuator rib 1213 engages with the leg operating surface 1523 of the actuator leg 1502 and moves axially together with the drop locking release flange 1114. Depending on the actual design of the different components, the actuator may be fully rotated (20 degrees here) during the mounting of the needle unit. As an alternative configuration, the final rotation of the actuator may occur when the actuator is then moved distally by a return spring 1590.

[0083] The axial mounting movement of the needle unit stops when the hub engages with the cartridge mount portion, indicating to the user that the needle unit is mounted on the cartridge hub. When the user stops pushing the container (or begins to pull the container away), the spring-biased actuator leg 1502 pushes the shield 1200 slightly distally until the distally facing axial stop surface 1221 on the shield assembly arm engages with the corresponding proximal facing stop surface 1121 on the hub tower portion. The control arms 1230 are moved back to their initial positions. Simultaneously, the clutch portion 1517 re-engages with the housing locking rib 1447 in the operating rotation position. As the shield moves distally, the shield operating rib 1213 moves into a closed engagement with the outer surface 1123 of the flexible hub arm, thereby preventing its radially outward movement. This securely locks the hub 1100 to the cartridge mount 1310, which corresponds to an operating hub coupling lock state that prevents the attached needle unit from being removed from the drug delivery device. See Figure 27D.

[0084] When the user pulls the container 1280 further distally to completely remove it, the container snap coupling 296 engages and disengages the shield 1200. Once the container is completely removed, the drug delivery device with the attached needle unit 1001 becomes usable, as shown in Figure 27E. In this state, the housing indicator opening 1405 aligns with the first indicator opening 241 and the hub indicator cutout 1115 of the shield. Thus, the hub skirt 1120 is not visible to the user (see Figure 28A).

[0085] When the user pushes the needle unit toward the skin surface, the shield 1200 is pushed proximal, allowing the distal end of the needle 1103 to be inserted subcutaneously. During the initial proximal movement of the shield, the inclined surface 1231 on the flexible control arm 1230 is pressed against the hub tower inclined surface 1131. As the shield moves further proximal to its fully retracted position, the shield actuator rib 1213 pushes a pair of actuator legs 1502 proximal, thereby releasing the drug delivery device discharge mechanism, and thereby initiating subcutaneous injection as described above. See Figure 27F. As shown in the figure, the actuator legs 1502 function as both a locking actuator for the hub coupling and a release member for the discharge mechanism. While discharging the drug, the shield is held in its fully retracted position by snap locks 1135, 1235. In this state, the housing indicator opening 1405 aligns with the second indicator opening 246 and the hub indicator cutout 1115 of the shield. Therefore, the hub skirt 1120 is not visible to the user (see Figure 28B).

[0086] After the clicking sound generated by the discharge mechanism ceases and the dose has been completely discharged, the user withdraws the needle unit from the skin surface, thereby allowing the spring-biased actuator leg 1502 to push the shield operating rib 1213, thereby moving the shield 1200 distally to its fully extended position, again covering the distal portion of the needle 1103. During this movement, the control surface 1232 on the control arm 1230 engages with the inclined proximal-facing control surface 1132 on the hub tower (see Figure 24A), which forces the needle hub 1100 to rotate as the shield is rotatably locked to the drug delivery device. See Figure 27G. In the illustrated embodiment, the hub rotates 45 degrees relative to the shield. Compare Figures 27CX and 27GX.

[0087] During the rotation of the hub relative to the shield, several structures move in and out of their engagement with each other.

[0088] (i) As the hub rotates, a portion of the hub skirt 1120 adjacent to the hub cutout 1115 aligned with the housing indicator opening 1405 rotates to align with the opening and is therefore visible to the user (for example, by having a contrasting color), indicating that the needle unit has been used and, accordingly, a dose of the drug has been dispensed. During drug dispensing with the shield in its retracted position, the second indicator opening 1246 of the shield aligns with the housing indicator opening 405 (see Figure 28C).

[0089] (ii) As the hub rotates, the flexible hub coupling arm 1126 rotates away from its engagement with the shield operating rib 1213, thereby allowing the coupling arm to move radially outward (see Figure 27H), and allowing the hub 1100 to be removed from the cartridge mount 1310. To reduce the force required to engage and disengage the hub coupling arm from the cartridge mount, the hub coupling arm is rotated to a position on the cartridge mount having the lower and lower inclined release flange portions 1312.

[0090] (iii) Once the needle is fixed within the hub, it will rotate with the rotating hub, but it is not always desirable for the needle to rotate when it is fully inserted subcutaneously. Accordingly, the hub and shield can be designed with axial "play" before the shield control surface 1232 engages with the inclined hub control surface 1132, which allows the needle to be withdrawn at least partially from the skin before rotation begins. In fact, subsequent rotation should begin with a more abrupt inclination of the hub control surface, and the inclination of the hub control surface should be abrupt.

[0091] (iv) Before the needle unit operates, a pair of locking ribs 1217 on the inner surface of the shield move freely in the axial direction, thereby allowing the shield to move from its extended position to its retracted position. As the hub rotates, a pair of distally facing locking surfaces 1118 rotate to align with the proximal ends 1218 of the locking ribs 1217, thereby preventing repeated retraction of the shield and therefore use of the needle unit, thereby providing a secure lock. See Figures 23B and 24A. Accordingly, the locking surfaces should be designed to withstand relatively large forces to prevent the needle unit from restarting, for example, if the pen-type device is dropped onto a hard surface or in misuse scenarios. Furthermore, if the shield is released in a drug delivery device such as in this embodiment, the shield lock also functions as a double-dose prevention means.

[0092] (v) In the illustrated embodiment, the container is also intended to be used as a tool for removing the needle unit. See Figure 27I. When the user reinstalls the container, the container snap coupling 1296 engages with the shield 1200. The container snap coupling is designed to have a release force greater than the release force required to axially pull the bulge 1127 of the flexible hub coupling arm away from engagement with the cartridge mount release flange 1312, thereby allowing the needle unit to be removed from the cartridge mount portion which is firmly held in the container, and then the needle assembly 1002 can be safely disposed of. See Figure 27J. Since the needle unit is locked to the container via the container snap coupling, and its proximal end is positioned at a specific distance inside the container and surrounded only by a small amount of free space, removal of the needle unit from the container is difficult.

[0093] (vi) As the hub rotates, the drop lock release flange 1114 rotates out of alignment with the actuator leg release surface 1524, thereby preventing the actuator drop lock from being released using the used and locked needle units.

[0094] Alternative embodiments: In the embodiments described above, when the hub rotates relative to the cartridge mount, the flexible coupling arm 1126 aligns with the rotating and inclined release flange 1312, allowing the hub coupling arm to be easily engaged and disengaged, thereby facilitating the user to remove the needle unit without using the container. To encourage the user to use the container, the release flange may be modified and configured to require a greater release force, which would make it more difficult to simply grab the shield and pull it out of engagement with the hub mount. To enable this, the snap coupling between the container and the shield would need to be able to transmit the required force, but this may be undesirable as the same snap coupling should be designed to allow for easy removal of the container after the initial installation of the needle unit.

[0095] Accordingly, a needle assembly including a snap coupling between a container and a shield may be provided, which is actuated between a first state in which the needle unit can be removed from the container using a first amount of force and a second state in which the needle unit can be removed from the container using a second, higher amount of force. The assembly may be actuated between the two states by the rotational movement of a hub inside the shield. A detailed description of such arrangements is given in concurrently pending application EP 23174814.6, which is incorporated herein by reference.

[0096] In the embodiments described above, the indicator is incorporated into the drug delivery housing and is operated by the rotational movement of the hub. The indicator operation is controlled by the needle unit, but the placement of the indicator window 1405 on the housing is designed to associate the indicator with the operation of the device itself, and thus indicates that a dose of the drug has been dispensed when the shield returns to its extended and locked positions.

[0097] However, instead of directly indicating that the needle module is in use and locked, it may be desirable to provide an indicator on the shield. Accordingly, instead of the device housing, the shield may be provided with an indicator window, and the hub may be provided with an indicator surface that is not initially aligned with the window but moves to align with it as the hub rotates after use.

[0098] The above description of exemplary embodiments has described different structures and means that provide the functionality described for different components to the extent that the concept of the present invention becomes clear to a skilled reader. Detailed structures and specifications for different components are considered to be subject to the usual design procedures performed by those skilled in the art along the lines specified herein.

Claims

1. A drug delivery assembly comprising a drug-filled cartridge (550) and a needle unit (2) that can be attached thereto, or a drug delivery device (3, 500) adapted to receive such a cartridge, wherein the drug delivery device is - A coupling means (511) that enables the needle unit to be attached to the drug delivery device, - An operable discharge mechanism adapted for the sequential discharge of a preset or user-defined amount of medication from the cartridge, - A drive spring (890) for driving the discharge mechanism, which is pre-stretched in accordance with a predetermined number of doses or a predetermined amount of drug, - Equipped with an operating means for operating the discharge mechanism, The aforementioned needle unit - Needle hub (100), - A hollow needle (200) mounted within the needle hub and having a pointed distal end protruding from the needle hub, wherein the hollow needle defines a reference axis, - A shield (300) on which a needle hub is fully or partially disposed, wherein the shield is axially movable relative to the needle hub between an initial extended position in which the distal end of the needle is axially covered, a retracted position in which the distal end of the needle protrudes from the shield, and a final extended position in which the distal end of the needle is axially covered. - A mounting coupling (126) that enables the needle unit to be attached to the drug delivery device, - Shield locking means (314, 115) that are activated when the shield is moved from the retracted position to the extended position, wherein the activated shield locking means includes a shield locking means that prevents the shield from retracting, When the needle unit (2) is mounted on the drug delivery device (3), the shield is adapted to activate the discharge mechanism operating means when the shield moves from the extended position to the retracted position. This prevents the discharge mechanism from operating twice when the same needle unit is installed in the drug delivery assembly.

2. A drug delivery assembly according to claim 1, wherein the mounting coupling (126) is - A locking state in which the attached needle unit (2) cannot be removed from the drug delivery device (3), - The needle unit can be detached from the drug delivery device, and it is operable between an operational release state and a state where it is released from operation. A drug delivery assembly wherein the mounting coupling (126) is activated from the locked state to the released state when the shield is moved from its retracted position to its final extended position.

3. A drug delivery assembly according to claim 1 or 2, - A drug delivery assembly in which the shield (300) is non-rotatably mounted on the drug delivery device (3).

4. A drug delivery assembly according to any one of claims 1 to 3, wherein the mounting coupling is - Flexible gripping fingers (126) adapted to grip the corresponding coupling structure (511) on the drug delivery device, - comprising a blocking means (313) adapted to block the radial movement of the gripping finger corresponding to a locked state in which the attached needle unit cannot be removed from the drug delivery device, A drug delivery assembly in which the flexible gripping finger (126) and the blocking means (313) are movable from a locked position relative to each other to a released position in which the gripping finger can move radially, thereby allowing the needle unit to be removed from the drug delivery device.

5. A drug delivery assembly according to claim 4, - A drug delivery assembly in which the flexible gripping finger (126) forms part of the needle hub (100) and the blocking means (313) forms part of the shield (300).

6. A drug delivery assembly according to any one of claims 2 to 5, - A drug delivery assembly in which the mounting coupling (126) is operated from the locked state to the released state by the rotational movement of the needle hub (100) relative to the shield.

7. A drug delivery assembly according to claim 6, - A drug delivery assembly in which the needle hub (100) and the shield (300) rotate relative to each other when the shield is moved from its retracted position to its final extended position.

8. A drug delivery assembly according to any one of claims 2 to 5, - The final extension position of the shield is distal to the initial extension position of the shield. - A drug delivery assembly in which the mounting couplings (240, 246) are activated from the locked state to the released state when the shield is moved from the retracted position to the final extended position.

9. A drug delivery assembly according to any one of claims 1 to 8, wherein the mounting coupling (126) is - An initial mounting state in which the needle unit can be mounted on the drug delivery device, - A drug delivery assembly that is further operable between the aforementioned locked state and the state described above.

10. A drug delivery assembly according to claim 9, - A drug delivery assembly in which the mounting coupling (126) is activated from the mounted state to the locked state by the axial movement of the shield (300) relative to the needle hub from the delivery position to the operating position.

11. The drug delivery assembly according to claim 10, wherein the shield operating position corresponds to the initial extension position.

Images