MEDICAMENT DELIVERY DEVICE

Abstract

A medicament delivery device is presented having a second housing part, a plunger rod arranged in the second housing part and configured to act on a stopper arranged inside a multi-chamber container. A first housing part contains the multi-chamber container, where the first housing part is arranged to be manually displaced into the second housing part by relative rotation between the first and the second housing parts for mixing at least two substances arranged inside the multi-chamber container. The delivery device further has a rotating contact element arranged between said plunger rod and said stopper capable of rotating in relation to said plunger rod.

Claims

1. A medicament delivery device comprising: a first housing part having a proximal end and comprising a multi-chamber container having a distal stopper and a proximal stopper separated by an axial distance; a second housing part that is movably attached to first housing part and where relative movement between of the first and second housing parts reduces the axial distance; a plunger rod rotationally fixed within the second housing part; and a rotating contact element positioned between the plunger rod and the distal stopper, where the rotating contact element is in a journaled connection to the plunger rod such that the rotating contact element will rotate relative to the plunger rod when in direct contact with the distal stopper, wherein relative movement between the first and second housings causes the distal stopper to move proximally relative to the proximal stopper for mixing at least two substances present inside the multi-chamber container.

2. The medicament delivery device of claim 1, wherein the first housing is rotatable relative to the second housings causes the multi-chamber container to move distally relative to the plunger rod.

3. The medicament delivery device of claim 2, wherein the second housing has a distal end separated by a distance from the proximal end and where the second housing part is threadedly attached to first housing part and where relative rotation reduces the distance between the distal and proximal end.

4. The medicament delivery device of claim 1 further comprises an activation member located in the second housing part that is operatively connected to a plunger rod.

5. The medicament delivery device of claim 1, wherein the first housing part comprises a thread on an outer surface and the second housing part comprises an inner surface having a corresponding thread engaged with the thread on the first housing part such that relative rotation of the first and second housing parts causes a distal end of the first housing to move adjacent the second housing part in a distal direction.

6. The medicament delivery device of claim 1, where the journaled connection comprises a shaft operatively connected to both the plunger rod and the rotating contact element such that rotation of second housing part relative to the first housing part causes rotation of plunger rod but not rotation of the rotating contact element.

7. The medicament delivery device of claim 1, wherein the journaled connection comprises a shaft having a proximal end and a distal end, where the distal end is fixedly attached to the terminal proximal end face of the plunger rod.

8. The medicament delivery device of claim 7, wherein the rotating contact element further comprises a disk having a central passage configured so that the disk is journaled to the proximal end of the shaft such that when the rotating contact element engages the distal stopper during the relative movement of the displacement of the first housing part relative to the second housing part the rotating contact element will rotate with the stopper and relative to the plunger rod and the shaft.

9. The medicament delivery device of claim 1, where the rotating contact element abuts the distal stopper to prevent the contacting element from rotating when the second housing part is rotated relative to the first housing part.

10. The medicament delivery device of claim 4, where the activation member comprises an activator sleeve having a flexible tongue that engages the plunger rod prior to the mixing of the two substances.

11. The medicament delivery device of claim 10, where the flexible tongue fits into a groove in the plunger rod to prevent axial movement of the plunger rod in the proximal direction.

12. The medicament delivery device of claim 10, further comprising a cover positioned at the distal end of the second housing part, where depression of the cover causes proximal movement of the activator sleeve causing the flexible tongue to disengage from plunger rod so the plunger rod can move axially toward the proximal end of the first housing part.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0025] In the following detailed description of the disclosure, reference will be made to the accompanying drawings, of which

[0026] FIG. 1 is a cross-sectional side view of the auto-injector according to the disclosure in a pre-mixed position,

[0027] FIG. 2 is a cross-sectional side view of the auto-injector according to the disclosure in a medicament mixed position,

[0028] FIG. 3 is a cross-sectional side view of the auto-injector according to the disclosure in a final position,

[0029] FIG. 4 is an exploded view of the auto-injector according to the disclosure,

[0030] FIG. 5 is a zoomed view of the distal part of the auto-injector according to the disclosure, and

[0031] FIG. 6 is a perspective view of a plunger rod and a rotating contact element.

DETAILED DESCRIPTION

[0032] In the present application, when the term “distal part/end” is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which is/are located the furthest away from the medicament delivery site of the patient. Correspondingly, when the term “proximal part/end” is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which, is/are located closest to the medicament delivery site of the patient.

[0033] The embodiment shown in the drawings comprises a proximal part 10 and a distal part 20, FIGS. 1-5.

[0034] The proximal part 10 comprises a generally tubular first housing part 12 having elongated openings for viewing a multi-chamber container 16 which is arranged inside, FIG. 1, and a somewhat narrowing proximal end. The multi-chamber container 16 comprises at least two medicament substances arranged in each chamber, a distal stopper 17, a proximal stopper 19, and redirecting passages between the chambers. The distal end of the first housing part is arranged with annular threads 18 on its outer surface. Moreover, the distal end is arranged with a neck portion having an inner diameter that is larger than the inner diameter of the rest of the body and thereby creating an annular ledge 14 between these two inner surfaces.

[0035] FIGS. 1-5 show the distal part or power unit 20 of the injector according to this disclosure. It comprises a second housing part 21, a plunger rod 25 formed as a tubular member and with an outer diameter somewhat smaller than the inner diameter of the container body to be used, a drive force means, an activation member 30 and a locking member 50. The plunger rod 25 has a terminal proximal end face 25a having an opening 25b, where the plunger rod 25 is arranged with a circumferential groove 26 with a certain width. Inside the plunger rod a drive force means (not shown) e.g. a helical compression spring, is pre-tensioned arranged and inside the spring a spring guide (not shown) is placed, as described below. On the proximal end of the plunger rod, a rotating contact element 60 is arranged such that it may rotate in relation to the plunger rod 25. In the embodiment shown the rotating contact element has a disk-shape with a central passage 61, FIG. 6, through which a shaft 62, FIG. 1, may extend. The shaft 62 is then attached to the terminal proximal end face 25a and opening 25b of the plunger rod 25.

[0036] Surrounding the plunger rod is the activation member 30 as e.g. an activator sleeve with a mainly tubular shape. Its proximal end comprises flexible locking means so as to form flexible tongues 39. Each tongue has an inclined transition surface 32 which meets with a band-shaped part 34 with enlarged diameter. On the inner surface adjacent the transition surface an annular inwardly directed ledge 36 is arranged, with a shape as to fit into the groove 26 of the plunger rod for holding the plunger rod and thereby said drive force means in a pre-tensioned state. The activator sleeve is further provided with hook means so as to form at least one flexible tongue 31. Each tongue 31 is arranged with an outwardly directed hook 37 at the outer end and a protrusion 33, with an inclined surface, a distance along each tongue. The distal end of the activator sleeve is arranged with a push button 35 protruding from said second housing part. A cover 40 having two tongues 41 attached to its outer edge and directed in the proximal direction of the device is attached to the push button.

[0037] Around the activator sleeve 30, a locking member 50, hereafter named actuator sleeve, also of a generally tubular form, is slidably arranged in relation to said activator between a first position wherein said locking member completely surrounds said locking means and a second position wherein said locking member partially surrounds said locking means after said locking member has been axially displaced by said first housing when said first housing has been displaced into said second housing part, as will be described. The actuator sleeve comprises a distal end with at least one distally extending tongue and a proximal end with a first annular part 52 on its outer surface. At a distance from the first annular part 52, a second annular part 56 ending in a ledge 58 is arranged on the outer surface.

[0038] The second housing part 21 is of a generally tubular shape, where the inner surface of the proximal end is arranged with threads 22 corresponding to the threads 18 of the first housing part 12 and provided with a number of annular protrusions which are intended to fit into the corresponding annular recesses on the inner surface of the second housing part 21. Moreover, the inner surface of the second housing part comprises radially holding means. Said radially holding means being an annular ring 23 provided with a circumferential ledge 24 with a shape corresponding to the hook 37 of the activator sleeve.

[0039] Further, a compression spring (not shown) is arranged surrounding the actuator sleeve 50 between the annular ring 23 and the second annular part 56 of the actuator sleeve.

[0040] The function of the injector according to this disclosure will now be described in connection with the FIGS. 1-4.

[0041] The injector will be delivered to the user as shown in FIG. 1, where a multi-chamber container is placed in the first housing part and the second housing part is attached to the proximal part.

[0042] When a mixing is to be performed, the first housing part is screwed into the second housing part until the plunger rod, which is static in relation to the container, has shifted the distal stopper axially with respect to the container such that medicament substances inside said multi-chamber container have been completely mixed, see FIG. 2. During the mixing, the rotating contact element 60 is abutting the distal end of the distal stopper and rotating relative to the plunger rod, whereby the rotational friction between the distal stopper and the plunger rod is greatly reduced. In the mixed position, the annular protrusions provided on the first housing part 12 fits into the corresponding annular recesses on the inner surface of the second housing part 21, and thereby locking said two bodies.

[0043] At the same time the distal end part of the first housing part 12 surrounds the proximal part of the actuator sleeve 50 such that the distal end ledge 14 of the first housing part 12 comes into contact with the proximal end of the first annular part 52 and with the ledge 58 respectively.

[0044] Moreover, when the mixing is performed, the actuator sleeve 50 is pushed axially towards the distal end of the device against the force of the compression spring acting between the second annular part 56 of the actuator sleeve and the annular ring 23 of the second housing part 21. The part of the band-shaped part 34 is then partially situated outside the proximal part of the actuator sleeve. The at least one distally extending tongue of the actuator sleeve will then come in contact with the inclined surface of the protrusion 33 of the at least one tongue 31 on the activator sleeve whereby the hook 37 is moved inwards and are free to pass inside the circumferential ledge 24.

[0045] The next step is to connect a needle or a safety pen needle to the proximal end of the first housing part 12 if the container is not a syringe, and to achieve a manual penetration of the needle into an injection site as e.g. the tissue of a patient. When activating the injection, the user merely depresses the cover 40 over the push button, FIG. 3, wherein the tongues 41 axially slides over the at least one flexible tongue 31. This causes the activator sleeve to be moved towards the proximal end of the device whereby the hooks 37 pass inside the circumferential ledge 24 and the band shaped part 34 is completely out of the actuator sleeve. The resilient properties of the tongues 39 of the activator sleeve causes the ledges 36 to move out of the groove 26 of the plunger rod, which then is free to move due to the helical compression spring inside the plunger rod. The force of the compression spring urges the plunger rod to push on the stopper of the container and the liquid medicament is injected into the patient until the stopper reaches the inner proximal end of the container.

[0046] It is to be understood that the flexible locking means are arranged to be released from said plunger rod only after said locking member is moved from the first position to the second position and said push button is axially moved into the second housing part, such that the flexible locking means comes completely out of contact with the locking member. If the mixing is not completely performed i.e. the first housing part has not been completely displaced into the second housing part such that said first housing part has not come into contact with said actuator sleeve, then said actuator sleeve has not been axially displaced towards the distal end of the device due to the force exerted by the compression spring arranged between the annular ring 23 and the second annular part 56 of the actuator sleeve. Moreover, if the user attempts to depress the push button before the mixing is completely done, the outwardly directed hooks 37 of the flexible tongues 31 will engage the annular ring 23 for avoiding premature activation of the device.

[0047] It is to be understood that the embodiment described above and shown in the drawings is to be regarded as a non-limiting example of this disclosure and that it is defined be the patent claims.