Drug Delivery Devices

Abstract

The present disclosure relates to a drug delivery device. The drug delivery device includes a housing having a proximal end and contains a pre-filled syringe positioned within the housing. The syringe has a needle, a dose of drug, and a sliding stopper. A tubular actuating member, such as a needle cover, is slidably positioned within the housing of the delivery device to move from a first position to a second position and then to a final locked position. The needle cover has two distally projecting arms and a proximal end portion terminating in a radial flange. The plunger rod can move proximally relative to the needle cover only when the needle cover is in the second position. The radial flange is positioned outside the proximal end of the housing when the needle cover is in the first position, the second position, and the locked position. The radial flange has an outer diameter D3, which is greater than the outer diameter D2 of the proximal end portion but less than the outer diameter D1 of the proximal end of the housing.

Description

[Technical field]

[0001] The present application relates to a medication delivery device with an automatic delivery mechanism that is activated by a delivery member guard when pressed against a dose delivery site. [Background technology]

[0002] Many drug delivery devices on the market and that have been deployed over the past two decades are referred to as auto-injectors because they require pressing the device against a dose delivery or injection site to be activated so that a dose of drug can be administered or injected directly into a patient. Upon activation, a compressed drive spring is released, which causes a plunger rod to expel the drug from a delivery member associated with a drug container. One such known auto-injector is disclosed in U.S. Pat. No. 5,399,433. User comfort and ease of use of auto-injectors, as well as safety features, are areas where design modifications can be made to improve the overall user experience and operational performance of such devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Pat. No. 9,199,038 Summary of the Invention [Problem to be solved by the invention]

[0004] In particular, the present disclosure relates to improved structural components for contacting the injection site, for improving the actuation experience of the device, for providing a smooth lockout feature to prevent user access to a used delivery member, and for improving the overall robustness of the injection device. [Means for solving the problem]

[0005] In this disclosure, when the term "distal" is used, it refers to a direction pointing away from the dose delivery site. When the term "distal portion / end" is used, it refers to a portion / end of a delivery device or a portion / end of a member of a delivery device that is located farthest from the dose delivery site (also referred to herein as the injection site) under use of the drug delivery device. Correspondingly, when the term "proximal" is used, it refers to a direction pointing towards the dose delivery site. When the term "proximal portion / end" is used, it refers to a portion / end of a delivery device or a portion / end of a member of a delivery device that is located closest to the dose delivery site under use of the drug delivery device. Both delivery member and injection needle are used herein to refer to a component that is placed at the dose delivery site and pushes the drug out.

[0006] It is an object of the present application to eliminate or ameliorate the perceived shortcomings of known automatic injection devices. This object is achieved by providing a more robust design that allows the user to experience a more responsive and smoother operation of the device. Furthermore, the design of the present disclosure aids in manufacturing quality and results in an easier lockout feature to prevent accidental contact with a used delivery member or attempts to reuse the device. Preferred embodiments of the present application form the subject matter of the dependent claims.

[0007] According to one aspect, the drug delivery device of the present disclosure has a tubular housing that is open at both the proximal and distal ends. An actuator having an end cap is located at the distal end and is fixedly fitted within the distal end opening of the housing. A plunger rod is partially assembled and positioned within the tubular proximal portion of the actuator and is initially in a first biased position. The plunger rod is hollow and has a closed proximal end. A compressed drive spring is positioned within the plunger rod and biases the closed proximal end in a proximal direction. The tubular proximal portion of the actuator has flexible fingers that releasably lock the plunger rod when the plunger rod is in the first biased position. A rotor is rotationally positioned around the tubular proximal portion of the actuator such that rotation of the rotor relative to the actuator, which is rotationally and axially fixed to the housing, unlocks the flexible fingers from the plunger rod.

[0008] The rotor has an outer surface configured with guide ledges, some of which extend axially in the longitudinal direction (i.e., parallel to the longitudinal axis of the delivery device) and some of which are inclined relative to the longitudinal direction. The guide ledges define one or more guide tracks that receive and form a passageway for one or more protrusions located on the distal end of the delivery member guard (also referred to herein as the needle cover). Axial distal movement of the needle cover and protrusions within the guide tracks results in actuation of the device. The guide tracks can have two or more non-linear paths that reduce the force required to actuate the device such that actuation of the device occurs when the rotor completes rotation relative to the housing and actuator. The guide tracks are again linear, i.e., parallel to the longitudinal axis of the delivery device. Completion of the rotation of the rotor releases the plunger rod from locking engagement with the free end of the flexible arm located on the actuator. In one possible embodiment, rotation of the rotor is triggered when a protrusion on the needle cover, moving axially and distally in the guide track, encounters a first ramped guide ledge. Further distal movement of the knob causes this protrusion to pass the so-called "point of no return" and simultaneously engage a second ramped guide ledge. Having two or more ramped guide ledges reduces the actuation force required and experienced by the user to initiate the automatic injection procedure.

[0009] The outer surface of the rotor may have a radially outwardly extending protrusion positioned on the end of the flexible finger. This protrusion forms part of a locking mechanism that is activated when the delivery member guard is removed from the injection site after a dose of medication has been administered by the injection device. The other part of the locking mechanism is a protrusion on the distal end of the delivery member guard. When the delivery member is moved away from the injection site, the delivery member guard will be biased out of the proximal end of the housing by a biasing element, such as a compression spring. At the same time, this protrusion will move proximally in a guide track on the rotor until it overcomes a wedge-shaped protrusion located at the end of the flexible finger. This design of the flexible finger must provide sufficient flexibility to ensure that the protrusion can easily move, i.e. slide over, past the protrusion without getting stuck, thereby ensuring that the protrusion is positioned behind, i.e. on the proximal side, of the wedge-shaped protrusion. When in this position, any attempt to move the delivery member guard distally will be inhibited as the protrusion will collide with and be stopped by the wedge shaped protrusion.

[0010] As previously mentioned, the drug delivery device has a needle cover (delivery member guard) slidably positioned within the proximal end of the housing. The needle cover has a radial flange located at the terminal proximal end that is designed to contact and engage an injection site, which is typically a preselected location on the user's skin tissue. The radial flange serves as a support surface when the user presses the outer housing in a proximal direction toward the injection site. This outwardly extending radial flange also provides a larger contact surface area compared to previously known needle cover designs. This increased contact area (surface area) provides a better user experience and comfort, especially for users with above average fat tissue. This is especially true when compared to previously known needle covers that do not have a radial flange feature. In one preferred design, the outer diameter of the radial flange is larger than the outer diameter of the proximal tubular portion of the needle cover and smaller than the outer diameter of the housing and the inner diameter of the safety cap.

[0011] To provide the greatest possible surface area to the proximal end face of the radial flange while still allowing for the use of a protective cap attached to the proximal end of the delivery device, the radial flange can have one or more notches along its periphery. These notches can be sized to receive longitudinal ribs positioned on the interior surface of the protective or safety cap. These notches can also be configured as improved attachment points to ensure that the safety cap remains removably attached to the delivery device before the delivery device is intended for use.

[0012] The delivery member guard may further comprise a distal end designed with two parallel longitudinally extending legs. The width and length of these legs are configured to maximize the robustness of the delivery member guard. Preferably, the thickness (T) of the legs is increased by about 19% compared to known similar longitudinal legs. Similarly, the widths (W2, W3) of the delivery member guard of the present disclosure are increased by about 8% and about 7%, respectively. Similarly, the distal ends of the legs are configured with a number of features that ensure smooth functioning of the actuation procedure when the delivery member guard is pulled distally back into the housing by pressing the delivery member guard against the injection site. These features may comprise rib guides that provide better slidable support because these rib guides are positioned longitudinally on the outer surface of each arm and form channels configured to receive ribs on the interior of the housing.

[0013] Another feature for enhancing operation of the device includes housing ribs positioned longitudinally on the interior of the housing and projecting radially outward from the interior surface of the housing. These ribs have a protruding thickness that cooperates with a rib guide on the distal end of the needle cover. The rib guide cooperates with the housing ribs to prevent rotation of the delivery member guard relative to the housing and to provide a guide path or surface to ensure smooth and snag-free sliding of the needle cover during actuation of the device. Preferably, the rib guide has a longitudinal length (L) that is about four times the length of the rib guide, which is also known. Preferably, this length L is proportional to the stroke (travel) length of the needle guard during actuation.

[0014] The above-mentioned protrusions located on the inner distal end surfaces of the longitudinally extending legs of the needle cover can be positioned and offset a distance from the terminal ends of the legs to delay or accelerate device actuation when the radial flange is pressed against the injection site. Moving these protrusions distally will accelerate actuation. The protrusions can further comprise chamfers or bevels at an angle of 20 degrees or less, which prevents jamming / catching of the legs of the delivery member guard as they slide within the track guide paths located on the outer surface of the rotor during actuation.

[0015] Further, the present disclosure may include a shipping lock assembly for the power pack of the drug delivery device. In some circumstances, the drug delivery device of the present disclosure may be delivered as multiple subassemblies that are coupled together in a final assembly procedure. For example, when assembling an auto-injector with a loaded or compressed drive spring, one such subassembly may be the power pack, where the compressed drive spring biases the plunger rod and the rotor is configured to release the pretensioned plunger rod in the final assembled delivery device. For this reason, the rotor is movable, so that other elements, typically part of a different subassembly, may interact with the rotor when a user of the drug delivery device wishes to administer a dose of drug. During shipping of the subassembly, vibration, movement, and shock may result in accidental or unintended release of the pretensioned plunger rod, which would render the power pack unusable to complete the device assembly. Therefore, it is desirable to ensure that the rotor is securely held or locked during shipping to prevent accidental activation of the power pack during shipping. At the same time, these locked power packs should not be difficult or complicated to unlock and / or assemble as a result of the shipping lock security measures.

[0016] The present disclosure may include a transportation lock assembly for a power pack that is unlocked upon final assembly. One such transportation lock assembly includes a power pack having a spring-biased plunger rod, a body that holds the spring-biased plunger rod in a pre-tensioned state, a rotor for releasing a spring-biased drive member from the body, and a locking member configured to interact with the rotor. The locking member is movable relative to the rotor from a first state in which the rotor is immobilized to a second state in which the rotor member is free to move, and the transportation lock assembly further features a housing portion having a key member. The housing portion is configured to receive the power pack, and assembly of the power pack to the housing portion causes the key member to move the locking member relative to the rotor from the first state to the second state.

[0017] Delaying the release of the rotor transport lock assembly is important to improve injection and dose delivery functions. One design method to intentionally induce this delay is to provide a notch on the inner distal end of the housing of the delivery device. Such an improved design prevents or delays the rotation of the rotor during the assembly stroke, preventing the needle cover knob from assembling in the wrong guide track, disabling the injection device. The shorter assembly stroke when the rotor is in the unlocked state potentially reduces the risk of misalignment.

[0018] To aid in efficient assembly of the drug delivery device of the present disclosure, several features can be included in the design, such as the use of one or more visible markers that allow for confirmation of alignment during the assembly process. For example, markers can be located on the rotor and on the outer surface of the housing near the opening in the housing, where the marker on the rotor is visible through the opening in the housing. Aligning these two markers during the assembly process ensures correct assembly. The inclusion of a chamfer and a blocking gate can also aid in the assembly process. For example, the inclusion of a combination of a chamfer and a blocking gate on the outer surface of the rotor can prevent misalignment of the legs of the delivery member guard when the power pack assembly 82 with the rotor is inserted and engaged into the distal end of the housing.

[0019] A protective cap is removably connected to the proximal end of the medication delivery device, typically having a generally tubular body and a generally tubular medication delivery member shield remover for removing the medication delivery member shield. The medication delivery member shield remover comprises a mounting element. The protective cap comprises a lid mounted to the tubular body, whereby the medication delivery member shield remover is held in place in this position by the end lid coming into contact with the mounting element of the medication delivery member shield remover. The mounting element is for holding the generally tubular medication delivery member shield remover. The lid is mounted to the body to hold the medication delivery member shield remover in a fixed position. This allows for easy and effective assembly of the safety cap.

[0020] Thus, in one possible embodiment of the present disclosure, a drug delivery device has a housing with a proximal end and contains a pre-filled syringe positioned within the housing. The syringe has a needle, a dose drug, and a sliding stopper. A tubular actuating member, i.e., a needle cover, is slidably positioned within the housing to move from a first position to a second position and then to a final locked position. The needle cover has two distally extending arms and a proximal end portion terminating in a radial flange. An elastic member, e.g., a compression spring, is located in the proximal end of the needle cover, and the spring is in a compressed state when the needle cover is in the second position. A plunger rod is operatively connected to the stopper and can move proximally relative to the needle cover only when the needle cover is in the second position. Each of the distally extending arms includes a distal portion that forms a lock when the needle cover is in the locked position, which prevents the needle cover from moving proximally relative to the housing and exposing the needle. The radial flange is positioned outside the proximal end of the housing when the needle cover is in the first position, the second position, and the locked position. The radial flange has an outer diameter D3 that is greater than the outer diameter D2 of the proximal end portion but less than the outer diameter D1 of the proximal end of the housing.

[0021] The radial flange may have two or more notches located along the outer periphery of the radial flange that are configured to receive longitudinal ribs on the interior surface of the safety cap.

[0022] Another aspect relates to a rotor for a drug delivery device. The rotor comprises a tubular body extending axially from a proximal end to a distal end relative to a longitudinal axis and one or more ridges extending from a surface of the tubular body. The one or more ridges define a track (211-213) on a surface of the tubular body, the track extending axially from the distal end of the track to the proximal end of the track, the track comprising one passage located at the distal end of the track and two passages located at the proximal end of the track. The two passages located at the proximal end of the track are separated by at least one of the one or more ridges. A first of the two passages (211, 212), located at the proximal end of the track, is bounded at its distal end by a portion of one or more ridges, the portion being angled with respect to the longitudinal axis, a first section (127a) of the portion being at a different angle with respect to the longitudinal axis than a second section (127b) of the portion. Optionally, the first section of the portion is at a larger angle with respect to the longitudinal axis than the second section. Additionally or alternatively, the second section is located closer to the distal end of the rotor than the first section. Additionally or alternatively, the first section is attached to the second section. Additionally or alternatively, the second section of the portion is at an angle with respect to the longitudinal axis between 10 degrees and 80 degrees, or between 20 degrees and 70 degrees, or between 25 degrees and 50 degrees. Additionally or alternatively, the first section of the portion is at an angle of between 20 degrees and 75 degrees, or between 30 degrees and 70 degrees, or between 30 degrees and 60 degrees, to the longitudinal axis. Additionally or alternatively, the first section is at an angle of between 5 degrees and 45 degrees, or between 5 degrees and 35 degrees, or between 10 degrees and 30 degrees greater to the longitudinal axis than the second portion.

[0023] These and other aspects and advantages of the present disclosure will become apparent from the following detailed description of the disclosure and the accompanying drawings.

[0024] In the following detailed description of the disclosure, reference is made to the accompanying drawings. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is an exploded view of a drug delivery device with a protective cap according to the present application. [Diagram 2] FIG. 2 is a cross-sectional view of the drug delivery device of FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view of the drug delivery device of FIG. 1. [Figure 4] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Diagram 5] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 6] FIG. 2 is a detailed view of a syringe holder forming part of the drug delivery device of FIG. 1. [Figure 7A] FIG. 2 is a detailed view of the needle cover of the drug delivery device of FIG. 1. [Figure 7B] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7C] FIG. 7B is a detailed view of the distal end of the needle guard of FIG. 7A. [Figure 7D] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7E] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7F] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7G] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7H] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7I] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7J] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 7K]FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 8] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 9A] FIG. 2 is a detailed view of the rotor of the device of FIG. 1. [Figure 9B] FIG. 9B is a detailed view of the rotor guide track of FIG. 9A. [Figure 10] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 11] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 12] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 13] FIG. 2 is a detailed view of the individual components that make up the drug delivery device of FIG. 1. [Figure 14] Detailed view of the rotor unlock sequence. The left part shows the first stage of the rotor unlock sequence, with the rotor lock still engaged (needle cover approximately in the rotor). The middle part shows the second stage of the rotor unlock sequence, with the rotor lock in a disengaged state. The right part shows the third stage of the rotor unlock sequence, with the rotor in an assembled (disengaged) state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The drug delivery device 10 shown in the drawings comprises a generally tubular housing 12 having a proximal end 14 and a distal end 15. A generally lateral wall 16 is disposed within the housing (FIG. 4) and the wall 16 comprises a central passageway 18. Further, cutouts 20 are provided on opposing sides of the passageway 18. A sheet 22 surrounds the passageway 18. A generally rectangular window 24 is disposed in the housing and is configured with inwardly oriented wall sections 26. Proximal portions of these wall sections 26 are attached to or form part of the lateral walls 16. A plurality of longitudinally extending ribs 30 and 80 are disposed on the inner surface of the housing at both the proximal and distal ends of the housing. An inwardly oriented projection 32 positioned as part of the cutout at the distal end of the housing has a generally radially deflecting tongue 34 configured with an inwardly extending ledge 36 at its free end. An assembly alignment indicator 204 is located on the outer surface of the proximal end of the housing 12 and is positioned adjacent the protrusion 32 and associated notched portion of the housing.

[0027] Coaxially disposed within the housing is a medicament container holder 38. The medicament container holder 38 comprises a generally elongated tubular body 40 having a distal passageway 42 and a proximal passageway 44. The proximal passageway 44 is configured with an inwardly oriented ledge 46 extending along the circumference. The body 40 is configured with two elongated slits 48 on opposing sides of the body, one of which extends the entire length to the proximal end to connect the slit to the proximal passageway, thereby forming a C-shaped appearance when viewed in the distal direction. The circumferential ledge is further configured with a number of notches 50, three in the illustrated embodiment, which provide flexibility to the proximal portion of the medicament container holder as will be described below. The longitudinal sides of the slit 48 are configured with outwardly oriented ledges 52 designed to come into contact with an inner surface 54 surrounding the window 24 of the housing to provide orientation and rotational fixation relative to the housing. The drug container holder 38 is configured to receive a drug container 56, which is illustrated in FIG. 2 as a prefilled syringe, having an injection needle 58 as a drug delivery member attached to the proximal end of the drug container 56 and a stopper 60 of elastic material slidably movable within the tubular body of the drug container 56.

[0028] The drug delivery device further comprises a drug delivery member guard 62, also referred to as a needle cover (see Figs. 1 and 7A). The delivery member guard 62 comprises a proximal generally tubular body 64 with a central passage 66 having a diameter that allows passage of the needle 58 during drug delivery. The needle guard 62 terminates at a proximal end in a transverse radial flange 68 that defines an injection site support surface. The radial flange 68 has an outer diameter D3 (see Fig. 7B) that is greater than the outer diameter D2 of the proximal end 64 but less than the outer diameter D1 of the housing 12. Two or more notches 200 are located along the circumference of the radial flange 68 and are sized to receive longitudinal ribs 139 located on the inner surface of the safety cap 132 (see Figs. 7E and 11). The ribs 139 define a diameter D5 that is smaller than the inner diameter D4 of the cap 132, which in turn is greater than the outer diameter D3 of the radial flange 68. Engagement of rib 139 with notch 200 prevents relative rotation of cap 132 with respect to housing 12 and needle cover 62. Cap 132 is coupled to housing 12 via rim 137 (see FIG. 7D).

[0029] An alternative safety cap 132 design is possible in which two of the four ribs 139 are eliminated and the remaining two ribs are shifted approximately 45 degrees from those shown in FIG. 7E. An example of such an alternative design is shown in FIG. 7I. Here, two ribs are positioned 180 degrees opposite each other, and the interior of the cap 132 is made flat or non-circular to create two contact points 132a, each 90 degrees from the ribs 139. These contact points 132a act as support walls for the proximal end of the needle cover 62.

[0030] Two oppositely positioned arms 70 are disposed and extend distally to the distal region of the body 64. The arms 70 are configured with longitudinal slits 72 that cooperate with the internal longitudinal ribs 30 of the housing (see FIG. 4). The arms 70 feature two different widths, namely W2 and W3 (see FIG. 7A). W2 is smaller than W3, both widths being selected to provide sufficient stiffness to prevent the needle guard from catching or bending when the radial flange 68 is pressed against the injection site prior to completing actuation of the drug delivery device and initiating dose delivery. The distal ends of the arms 70 are provided with radially outwardly oriented ledges 74. Preferably, two such ledges are used on each distal end of the arms 70, oriented and spaced longitudinally to define a channel having a width W1. The channel is sized to receive the interior longitudinal ribs 37 (see FIG. 4) of the housing 12, which act as guide tracks for the distal sliding movement of the needle guard relative to the housing as the delivery device is pressed and pressed against an injection site. As shown in FIG. 7D, in one possible embodiment, the ratio of the width (WR) of the radially oriented ledge 74 to the width (WH) of the housing ribs 37 is about 1.18.

[0031] Preferably, the tolerance between WR and WH is designed to be as small as possible to limit the radial movement of the needle guard relative to the housing 12. By reducing the space tolerance between WR and WH, the risk of derailment between the needle guard and the housing arms during axial movement of the needle guard is significantly reduced. Similarly, by minimizing the ratio of WR:WH, the gear ratio between the needle guard and the housing is improved, which also significantly reduces the twisting and derailment of the needle guard arms. Another possible solution to prevent the twisting or derailment of the arms is shown in FIG. 7J. This figure shows a geometric self-locking design, where the housing rib 37 is configured with an angled engagement portion 37a that slidably engages with the inner surface of the ledge 72 on the needle guard. This angled engagement biases the radially inwardly oriented protrusion 76 to slidably engage with the sidewalls 126, 127 of the guide track 211, thereby preventing the twisting and derailment of the needle guard arms.

[0032] In another possible design, as shown in FIG. 7G, the height HL of the radially outwardly oriented ledge 74 is maximized to better guide the axial movement of the needle guard as it moves distally along the longitudinal housing rib 37 (see FIG. 7J). This longitudinal housing rib 37 has a height HR, not shown in FIG. 7J, as shown, with a ratio of HL to HR of about 2.6:1 when HL is measured at the bottom of the draft 74b. The ledge 74 also has a guide wall interaction feature 74a that ensures that the housing rib 37 smoothly enters the channel defined as the space between the ledges 74. This particular design also prevents flexing of the needle guard arm 70 as the needle guard moves axially distally. Further, to prevent arm 70 from binding or bending when moved axially relative to the interior of housing 12, a web or wall 12a is preferably provided on the interior surface of the housing, as shown in FIG. 7H, thereby minimizing the space between arm 70 and the housing or providing a tighter fit between arm 70 and the housing.

[0033] On the inner surface of the arm 70 there is a protrusion 76 oriented radially inward (see FIG. 7C). The protrusion 76 is preferably teardrop shaped with a beveled or chamfered edge 76a of less than 58 degrees, preferably 20 degrees or less, and most preferably 15 degrees or 8 degrees, as measured relative to the inner surface 76c of the leg 70. These angled chamfers will prevent or minimize the undesirable malfunction mode of delayed actuation. The distance of these protrusions is predetermined to achieve the desired needle injection depth. The protrusions 76 are positioned at a distance 76b from the distal terminal end of the leg 70. As suggested, the delivery member guard can also have a distal end designed with two parallel longitudinally extending legs. The width and length of these legs are configured to maximize the robustness of the delivery member guard. Preferably the thickness (T) of the legs is approximately 19% greater than known similar longitudinal legs (see FIG. 7A). Similarly, the widths (W2, W3) of the delivery member guard of the present disclosure are increased by approximately 8% and 7%, respectively. The protrusion 76 is moved by 0.25 mm to delay actuation.

[0034] A drug delivery member guard spring 78 is further disposed between the distally oriented surface of the radial flange 68 of the needle cover 62 and the proximally oriented surface of the wall 16. In this regard, a proximally oriented support protrusion 80 (see FIG. 5) is provided on the wall 16 to support the drug delivery member guard spring 78 and to prevent the spring 78 from accidentally interacting with the arm 70 of the needle cover 62. The spring 78 biases the needle cover before, during, and after activation of the delivery device and completion of drug delivery at the injection site. FIG. 7D illustrates the spatial relationship of the housing 12, the needle cover 62, and the proximal end of the needle 58 when the radial flange 68 is pressed against the injection site and drug delivery is initiated. The length of the housing 12 and / or the needle cover 62 is preselected and designed such that L2 is 1.5 mm or greater to avoid the proximal terminal end of the housing contacting the injection site, which may cause discomfort to the user. Similarly, the rim 137 is located a distance L1 from the proximal terminal end of the housing to avoid interaction with the injection site, L1 being preferably 3 mm or greater.

[0035] The drug delivery device 10 shown in Fig. 1 further comprises a power pack or drive unit 82. The power pack 82 comprises an actuator 84 (Fig. 8) whose distal portion forms an end cap 86 of the distal end of the housing 12 of the drug delivery device when the power pack is inserted and fitted into the housing. The proximal portion of the actuator 84 comprises a generally elongated tubular body 88. A lateral support surface 90 is arranged in the region between the end cap 86 and the body 88, which support surface 90 is designed to cooperate with the ledge 36 of the tongue 34 on the housing 12 to lock the actuator 84, and thus the power pack, relative to the housing 12 when the device is fully assembled. Furthermore, the body 88 is configured with proximally oriented arms 92 that are generally radially flexible. The free ends of these arms 92 comprise inwardly oriented protrusions 94. These inwardly oriented protrusions 94 are positioned to fit within and cooperate with recesses or notches 95 in an elongated plunger rod 96. The plunger rod 96 is a hollow tubular structure having a closed proximal end and an open distal end, the plunger rod being intended to fit coaxially within the body 88 of the actuator 84.

[0036] The rotor 122 may also have an alignment indicator 206 visible through a notch 32a located at the distal end of the housing 12. During device assembly of the power pack 82 within the housing 12, the rotor is positioned and oriented relative to the housing such that the alignment indicator 204 aligns with the alignment indicator 206 on the rotor. The alignment indicator 206 is a small but detectable sink notch that is visible through the notch 32a after final assembly and is used to verify the alignment of the rotor 122 throughout the lifecycle of the device.

[0037] Furthermore, a drive spring 98 is partially disposed within the hollow portion 96a of the plunger rod 96, and a guide rod 110 is disposed within the drive spring 98, the guide rod having a disk 112 at its distal end. A U-shaped bracket 100 has a lateral distal portion 102 and two proximally extending arms 104 on either side and on the exterior of the drive spring 98. The ends of the arms 104 are configured with outwardly extending ledges 106 that come into contact with proximally oriented edge surfaces 108 of the body 88 of the actuator 84. The drive spring 98 is thus disposed between a proximal end wall 114 of the plunger rod 96 and the lateral distal portion 102 of the bracket 100, via the disk 112 of the guide rod 110 (see FIGS. 2 and 8). Furthermore, at the proximal end of the body 88, there is an arc-shaped support element 116 that protrudes proximally and is generally longitudinally flexible. These elements 116 are intended to come into contact with and support the medicament container 56, thereby minimizing relative axial movement of the container 56 with respect to the medicament container holder 38. Preferably, the elements 116 apply a proximal biasing force to prevent undesired axial movement of the container 56. In other words, contact or engagement by the elements 116 may apply a proximal biasing force to the medicament container holder 38 and / or the medicament container itself.

[0038] The free ends of the arms 92 of the body 88 are configured with outwardly oriented projections 118 intended to cooperate with an inner surface 120 of a generally tubular rotor 122 arranged coaxially on the exterior of the body 88 of the actuator 84. As shown in FIG. 9A, the inner surface 120 of the rotor 122 is configured with a longitudinally extending groove 124, the function of which will be explained below. The outer surface of the rotor 122 is configured with a number of guide ledges or ribs 126a-126c and 127a-127b defining one or more guide tracks 211-213, some of which extend in a longitudinal direction 126a, 126b, and 126c and some of which are inclined with respect to this longitudinal direction, as shown by the section 127, which will be explained below. Adjacent to one longitudinal guide rib 126b is arranged a proximally oriented tongue 128. The tongue 128 is generally radially flexible, and the free end of the tongue 128 defines an outwardly oriented wedge-shaped projection 130 .

[0039] To activate the drug device of the present disclosure, the needle cover 62 must be pulled back into the housing 12 by pressing the needle cover 62 against the injection site. At this time, the protrusion 76 moves toward the proximal end of the rotor 122, which causes the protrusion 76 to enter the track 211 (see Figures 9A-9B). To prevent misalignment or jamming of the sliding movement of the needle cover 62 relative to the housing 12, an edge 208 and an angled edge 210 are provided to guide the protrusion 76 into the track 211. Initially, the needle cover follows the guide ledge 126a and moves along the track 211. At first, the user only needs to overcome the biasing force of the compression spring 78. However, as the needle cover is pushed further into the housing, the protrusion 76 encounters an angle change in the wall of the guide ledge 127a and then a second angle change caused by the guide ledge 127b. Both of these angular transitions define a guide track 212. The projection 76 will then enter the guide track 213. As the needle cover is pushed along these angular transitions, the spring 78 will be compressed further. This will require the user to apply more force than if the user were to simply compress the spring 78 further along a linear track. By engaging the angled guide ledges, the rotor 122 will begin to rotate in a clockwise direction relative to the needle cover, the body 88, and the housing 12. As the projection moves past the first angled guide ledge 127a, the user will notice a reduction in the force required to be applied as the needle cover passes the point of no return. Further axial movement along the second angled guide ledge 127b distal to the needle cover will cause the rotor 122 to rotate further. Once the rotor has completed its rotation, the projection 76 will then align and enter the guide track 213. At this point, the applied force decreases further and then continues to increase until spring 78 is further compressed and the needle cover eventually reaches the retracted position as shown in FIG. 7D.

[0040] The drug delivery device 10 is further configured with a safety cap 132 (FIGS. 1 and 10-11) comprising a generally tubular body 134 having a distal passageway 136. To achieve a good fit between the safety cap 132 and the housing 12 of the drug delivery device 10, an inner surface of the body 134 of the safety cap 132 may be configured with a circumferential ledge 138. The ledge 138 is arranged to interact with a protrusion 140 (FIG. 7) located on an outer surface of the body 64 of the drug delivery member guard 62 as shown in FIG. 14. The body 134 of the safety cap 132 is further configured with a distally oriented end surface 135 (see FIG. 11) which serves as an abutment surface for a proximally oriented end surface, such as a rim 137 (FIG. 7D) of the housing 12. This rim 137 also functions as an abutment surface, and these surfaces 135 , 137 provide a specific location for the protective safety cap 132 when it is attached to the medication delivery device 10 .

[0041] The body 134 of the safety cap 132 is configured with a proximal end wall 142 configured with a central circular passage 144. Radially outwardly of the central passage 144 are arc-shaped openings 146 positioned on two opposite sides. Alternatively, only one opening of some suitable shape may be provided (not shown here). A generally tubular drug delivery member shield remover 148 will be positioned within the central passage 144 of the end wall 142, the drug delivery member shield remover 148 extending into the body 134 of the safety cap 132. The proximal end of the drug delivery member shield remover 148 is configured with an outwardly extending ledge 150, the ledge or flange 150 being arranged to seat within a seat or recess 152 in the end wall 142 of the body 134. The drug delivery member shield remover 148 is held fixed in place at this position by an end cap 154 ​​which is configured with two distally oriented arcuate arms 156 with radially outwardly oriented ledges 158 as shown in FIG. 11. The arms 156 are designed to fit within the arcuate opening 146 of the body 134 and the ledges 158 snap around the edges of the arcuate opening 146 to lock the end cap 154 ​​to the body 134 of the safety cap 132. Alternatively, only one appropriately shaped distally oriented arm or an arm with two flexible fingers (not shown) may be provided. Further, the end cap 154 ​​is configured with one or more distally oriented protrusions or ledges 160 that come into contact with the ledges 150 of the drug delivery member shield remover 148 to hold the drug delivery member shield remover 148 in a fixed position within the recess 152.

[0042] The distal end of the drug delivery member shield remover 148 is configured with a tongue 168 that is generally inclined proximally and inwardly. The tongue 168 is designed to come into contact with and engage a drug delivery member shield 170, e.g., a rigid or flexible needle shield, that covers a drug delivery member, e.g., an injection needle 58. The assembly procedure of the protective safety cap is facilitated in that the drug delivery member shield remover 148 is simply inserted from the proximal side into the central passage 144 of the end wall 142 of the body 134 until the ledge 150 seats in the recess 152 in the end wall 142. The end cap 154 ​​is then simply pressed against the proximal end of the body 134, so that the arms 156 fit into said openings and the ledge 158 snaps around the edge of the opening 146 of the body 134. This solution results in a very simple, fast and effective assembly method of the protective safety cap.

[0043] 12A and 12B show yet another possible design of the safety cap assembly 132. This design, also referred to as a three-component configuration, has a circular shield remover connector 134a facing in a distal direction. The circular shield remover connector 134a has an extending groove 134b on an inner portion that is configured to easily engage a corresponding outward projection 148a on the proximal end of the delivery member shield remover 148. As shown by the directional arrows in FIG. 12A, the shield remover is first attached to the body 134, and then the end cap 154 ​​is inserted and coupled. This simplifies assembly of the safety cap assembly 132, yet ensures that the shield remover is axially secured to the body 134 when the user removes the safety cap assembly from the delivery device housing.

[0044] The outward projection 148a is sized such that when the safety cap is to be removed from the delivery device housing, a secure snap fit is formed between the inwardly extending groove 134b to axially secure the remover shield against the inside of the proximal end of the body 134. As shown in FIG. 12B, the body 134 has two axial positions relative to the remover 148. The first position is an assembly position in which the remover is inserted through the distal end of the body 134 and the end cap 154 ​​is inserted into a through hole located at the distal end of the body 134, thereby holding the remover in place. In this assembly position, the distal end of the remover bottoms out on the end cap, thereby defining an axial movement gap AM between the outward projection 148a and the inwardly extending groove 134b. This gap AM allows axial movement of the body 134 relative to the remover when a user begins the process of removing the safety cap assembly from the delivery device housing. When the body moves to a second axial position relative to the remover, the inwardly extending groove 134b then engages the outwardly protruding portion 148a, and continued axial movement of the body also causes axial movement of the remover. The presence of the gap AM makes it easier for the user to remove the safety cap assembly from the housing of the delivery device, i.e., less force is required to do so, because the remover and RNS do not initially move out of the syringe, only the body moves. The size of the gap AM is predetermined so that the body is released from the housing of the delivery device before the remover begins to move axially with the body 134.

[0045] 12B, the RNS remover stands on the bottom of the cap that sits on the syringe assembly. When removing the cap, the RNS remover moves to a second position to allow release of the cap before the RNS begins to move relative to the syringe.

[0046] The design of the outward projections 148a and inwardly extending grooves 134b preferably allows rotation of the safety cap body 134 relative to the remover 148, but prevents relative axial movement of the projections 148a and grooves 134b once engaged when the body is in the second axial position. The distally extending ribs 154a on the interior surface of the end cap 154 ​​prevent or significantly reduce the shield remover from becoming misaligned, tilted, or otherwise misaligned with respect to the longitudinal axis 132a of the cap assembly 132. The cap assembly shown in FIG. 12A also includes an opening 132b on the proximal end of the body 134 that provides an air passage through the safety cap 132 to reduce the possibility of choking if, for example, a child places the safety cap 132 in their mouth.

[0047] FIG. 14 shows one possible embodiment of the rotor transport lock feature 86a, which can be used during assembly of the device to prevent premature or undesired rotor rotation that can cause the distal end of the needle guard to misalign with the rotor guide track as described above. Preferably, the interior of the housing 12 includes deep grooves 12a at the distal end that become shallower as they extend toward the proximal end of the housing. The change in depth of the grooves 12a allows the injector power pack assembly 82 with the rotor component 122 to be advanced further into the housing (e.g., 3-4 times further than previously possible) until the rotation lock 86a of the rear cap 86 disengages, allowing the rotor 122 to rotate freely. The needle cover protrusion is then located very close to the axial position of the guide track opening of the rotor 122 when the rotation lock 86a is disengaged. In FIG. 14, the rotor unlock sequence is shown.

[0048] The medication delivery device according to these figures is intended to function as follows: the medication delivery device is delivered to a user with a safety cap 132 attached to the proximal end of the medication delivery device. The medication delivery member guard 62 is in an extended position relative to the housing 12 such that when an abutment surface 135 of the safety cap 132 comes into contact with an abutment surface 137 of the housing, a circumferential ledge 138 is located distal to and in contact with a protrusion 140 of the medication delivery member guard 62 as shown in Figure 14. This provides a very secure fit, thereby reducing the risk of the safety cap 132 being released prematurely.

[0049] To ensure a smooth and uninterrupted assembly of the safety cap 132 to the housing 12 of the delivery device, it is desirable to reduce or eliminate unwanted physical contact between the needle guard 62 and the interior of the safety cap 132. This may be accomplished by providing a chamfered edge 63 at the proximal end of the needle guard 62 (see FIG. 7K). Similarly, the interior surface 133 of the cap 132 may be configured to have no excess wall material that may scrape, snag, or otherwise engage the proximal end of the needle guard. Similarly, the inwardly protruding surface 139a of the longitudinal rib 139 may be configured to have minimal or no engagement with the proximal end of the needle guard. Increasing the contact surface area 134a of the distal end of the safety cap 132 is preferred to ensure a secure fit with the housing 12.

[0050] The drug delivery device is typically actuated by forcing the needle cover 62 into the housing 12 when the radial flange 68 is pressed against a dose delivery site, e.g. an injection site, as described below. In certain circumstances, actuation may be caused unintentionally. For example, this may occur accidentally if the drug delivery device is dropped against a hard surface, e.g. a floor. Such an accident may pose a risk of actuation of the drug delivery device 10, as the force of the impact may cause the needle cover 62 to move relative to the housing 12, which may trigger the drug delivery device. This risk is reduced or eliminated because the needle cover 62 is held in engagement with the safety cap 132 by the projection 140 interacting with the ledge 138.

[0051] Once the safety cap has been removed together with the needle shield, the user can then press the radial flange 68 against the injection site, which forces the needle cover 62 into the housing 12 and causes penetration by the injection needle 58. This movement of the needle cover 62 causes the projection 76 located at the distal end of the needle cover to slide against the rotor 122. The projection moves along a guide track on the rotor's outer surface, which causes the rotor to rotate relative to the actuator 84, which then moves the outward projection 118 of the arm 92 of the actuator 84 into position within the longitudinal groove 124 on the inner surface 120 of the rotor 122. The arm 92 is then free to move radially outward, releasing the engagement between the inwardly oriented projection 94 and the recess 95 of the plunger rod 96, which is then released. The plunger rod 96 is then biased proximally by the force of the compressed drive spring 98. As a result, the plunger rod 96 acts on the stopper 60 of the drug container 56 to move it proximally, forcing the drug dose through the injection needle 58. At the end of the injection sequence, the distal end of the plunger rod 96 passes through the bracket 100, which frees the arms 104 of the bracket 100 to move radially inwardly and the ledges 106 out of contact with the surface 108 of the actuator 84. The contact of the distal end of the drive spring 98 with the lateral distal portion 102 of the bracket 100 via the disk 112 of the guide rod 110, and the residual force of the drive spring 98, causes the bracket 100 to be rapidly urged in the distal direction until the distal end of the bracket 100 impacts the end wall of the actuator 84, which provides tactile and audible signals to the user that the injection sequence is complete and that it is safe to remove the drug delivery device from the dose delivery site.

[0052] At this time, the user can remove the radial flange from the injection site, which in turn allows the needle cover 62 to be pushed proximally by the initially compressed drug delivery guard spring 78 as a result of the needle cover being pushed distally during contact between the radial flange and the injection site. The proximal biasing force caused by the spring 78 decompressing causes the needle cover and protrusion 76 to move proximally in the guide track 213, thereby coming into contact with and passing the wedge-shaped protrusion 130 of the tongue 128 of the rotor 122. The protrusion 76 rides over the protrusion 103 and eventually comes to rest on the proximal side of the tongue 128. As a result of the protrusion 130 passing over the protrusion 76, the tongue 128 acts as a hard stop, preventing distal axial movement of the protrusion 76. Thus, the needle cover 62 is locked in the extended position to cover the injection needle 58 and further prevent accidental damage to the injection needle 58. The medication delivery device can now be disposed of.

[0053] It is to be understood that the embodiments described above and shown in the drawings should be considered solely as non-limiting examples which can be modified in various ways within the scope of the claims. [Explanation of symbols]

[0054] 10 drug delivery device, 12 generally tubular housing, 12a web, wall, groove, 14 proximal end, 15 distal end, 16 generally lateral wall, 18 central passage, 20 notch, 22 seat, 24 window, 26 wall section, 30 longitudinally extending rib, 32 protrusion, 32a notch, 34 tongue, 36 inwardly extending ledge, 37 longitudinal rib, longitudinal housing rib, housing rib, 37a angled engagement portion, 38 drug container holder, 40 generally elongated tubular body, 42 distal passage, 44 proximal passage, 46 ledge, 48 slit, 50 notch, 52 ledge, 54 inner surface, 56 drug container, 58 injection needle, 60 stopper, 62 drug delivery member guard, needle guard, needle cover, 63 chamfered edge, 64 proximal generally tubular body, proximal end, 66 central passage, 68 lateral radial flange, 70 arm, leg, 72 longitudinal slit, ledge, 74 ledge, 74a guide wall interaction feature, 74b draft, 76 protrusion, 76a beveled edge, chamfered edge, 76b distance, 76c inner surface, 78 drug delivery member guard spring, 80 support protrusion, longitudinally extending rib, 82 power pack, drive unit, power pack assembly, 84 actuator, 86 end cap, rear cap, 86a rotor transport lock feature, rotation lock, 88 generally elongated tubular body, 90 lateral support surface, 92 arm, 94 protrusion, 95 recess, notch, 96 elongated plunger rod, 96a hollow portion, 98 drive spring, 100 U-shaped bracket, 102 lateral distal portion, 103 protrusion, 104 proximally extending arm, 106 outwardly extending ledge, 108 edge surface, 110 guide rod, 112 disk, 114 proximal end wall, 116 arcuate shaped support element, 118 outward protrusion, 120 inner surface, 122 rotor, generally tubular rotor, rotor component, 124 longitudinally extending groove, 126 side wall, 126a guide ledge, rib, 126b guide ledge, rib, 126c guide ledge, rib, 127 side wall, section, 127a guide ledge, rib, 127b guide ledge, rib, 127c guide ledge, rib, 128 tongue, 130 wedge shaped protrusion, 132 safety cap, protective safety cap, safety cap assembly, 132a contact point,longitudinal axis, 132b opening, 133 inner surface, 134 generally tubular body, safety cap body, 134a circular shield remover connector, contact surface area, 134b inwardly extending groove, 135 end surface, abutment surface, 136 distal passageway, 137 rim, abutment surface, 138 circumferential ledge, 139 longitudinal rib, 139a inwardly protruding surface, 140 protrusion, 142 proximal end wall, 144 central circular passageway, 146 arcuate shaped opening, 148 generally tubular drug delivery member shield remover, 148a outwardly protruding portion, 150 outwardly extending ledge, flange, 152 recess, 154 end cap, 154a rib, 156 arcuate shaped arm, 158 ledge, 160 ledge, 168 tongue, 170 Drug delivery member shield, 200 notch, 204 assembly alignment indicator, 206 alignment indicator, 208 edge, 210 angle edge, 211 guide track, 212 guide track, 213 guide track,

Claims

1. 1. A rotor for a medication delivery device, comprising: a tubular body extending axially from a proximal end to a distal end relative to a longitudinal axis; one or more ridges extending from a surface of the tubular body, the one or more ridges defining a track (211-213) on the surface of the tubular body, the track extending axially from a distal end of the track to a proximal end of the track, the track comprising one passageway located at the distal end of the track and two passageways located at the proximal end of the track, the two passageways located at the proximal end of the track being separated by at least one of the one or more ridges; Equipped with a rotor in which a first of two passages (211, 212) located at the proximal end of the track is bounded at the distal end of the first passage by one or more ridge portions, the portions being angled with respect to the longitudinal axis, a first section (127a) of the portion being at a different angle with respect to the longitudinal axis than a second section (127b) of the portion.

2. The rotor of claim 1 , wherein the first section of the portion forms a greater angle with respect to the longitudinal axis than the second section.

3. 3. A rotor as claimed in claim 1 or 2, wherein the second section is located closer to the distal end of the rotor than the first section.

4. A rotor as claimed in any preceding claim, wherein the first section is mounted relative to the second section.

5. A rotor as claimed in any one of claims 1 to 4, wherein the second section of the portion forms an angle with the longitudinal axis of between 10 degrees and 80 degrees, or between 20 degrees and 70 degrees, or between 25 degrees and 50 degrees.

6. A rotor as claimed in any one of claims 1 to 5, wherein the first section of the portion forms an angle with the longitudinal axis of between 20 degrees and 75 degrees, or between 30 degrees and 70 degrees, or between 30 degrees and 60 degrees.

7. 7. A rotor as claimed in any one of claims 1 to 6, wherein the first section forms a greater angle with respect to the longitudinal axis than the second portion by between 5 degrees and 45 degrees, or between 5 degrees and 35 degrees, or between 10 degrees and 30 degrees.

8. A drug delivery device comprising a rotor according to any one of claims 1 to 7.

9. The drug delivery device of claim 8 , wherein the drug delivery device is an auto-injector.

Images