US-12623031-B2 - Medicament delivery device

US12623031B2US 12623031 B2US12623031 B2US 12623031B2US-12623031-B2

Abstract

The present disclosure relates to a medicament delivery device. The medicament delivery device comprises a housing, a needle, and a needle cover. The needle cover is axially movable between an extended position and a retracted position. The medicament delivery device comprises a needle cover biasing member configured to bias the needle cover axially in the distal direction towards the extended position. The needle cover biasing member is configured to transition from a non-buckled state to a buckled state during proximal movement of the needle cover from the extended position to the retracted position. The present disclosure also relates to a method of preparing a medicament delivery device, and a method of locking a medicament delivery device.

Inventors

Timothy Denyer
James Bradford
Alexander Hee-Hanson
Robert Wilson
Dean TWITE
Thomas LEVER

Assignees

GENZYME CORPORATION

Dates

Publication Date: 20260512
Application Date: 20240829

Claims (14)

1 . A medicament delivery device comprising: a housing comprising a proximal end and a distal end; a needle and a needle cover, wherein the needle cover is axially movable between an extended position, in which the needle cover extends from the distal end of the housing and covers a distal end of the needle, and a retracted position, in which the needle cover is located in a proximal position relative to the extended position such that the needle protrudes from a distal end of the needle cover; and a needle cover biasing member configured to bias the needle cover axially in a distal direction towards the extended position, wherein the needle cover biasing member is located within the needle cover, wherein the needle cover biasing member is configured to transition from a non-buckled state to a buckled state during proximal movement of the needle cover from the extended position to the retracted position, wherein when the needle cover biasing member is compressed yet before the needle cover biasing member has transitioned from the non-buckled state into the buckled state, the needle cover biasing member is arranged substantially along an axis, wherein the axis is defined by a first end of the needle cover biasing member and a second end of the needle cover biasing member that is opposite to the first end, and the axis is parallel to and radially outward from a longitudinal axis of the needle.
2 . The medicament delivery device according to claim 1 , wherein the needle cover biasing member is configured to elastically buckle from the non-buckled state to the buckled state.
3 . The medicament delivery device according to claim 2 , wherein when the needle cover is in the retracted position, the needle cover biasing member in the buckled state is configured to provide a restoring force to move the needle cover to the extended position once a compressive force on the needle cover is removed.
4 . The medicament delivery device according to claim 1 , wherein the needle cover biasing member is configured to transition to the buckled state once the needle cover has travelled over 50% of a distance from the extended position to the retracted position.
5 . The medicament delivery device according to claim 1 , wherein the needle cover comprises a flange located proximate the distal end of the needle cover, a distal end of the needle cover biasing member being mounted to the flange and the a proximal end of the needle cover biasing member being mounted to a mount proximate the distal end of the housing.
6 . The medicament delivery device according to claim 1 , wherein the needle cover biasing member comprises a coil spring.
7 . The medicament delivery device according to claim 6 , wherein the coil spring has a slenderness ratio of greater than or equal to 4.
8 . The medicament delivery device according to claim 6 , wherein the coil spring is configured to buckle when a deflection of the coil spring to free height ratio is between 0.25 and 0.65.
9 . The medicament delivery device according to claim 1 , wherein the needle cover biasing member is located radially inwards of an outer surface of the needle cover.
10 . The medicament delivery device according to claim 1 , wherein the medicament delivery device is configured to inject greater than 2 ml of a medicament and/or wherein the medicament delivery device is configured to inject a medicament having a viscosity of greater than 25 cP.
11 . The medicament delivery device according to claim 1 , wherein the medicament delivery device is configured to prevent the proximal movement of the needle cover once the needle cover is in the extended position post-use.
12 . The medicament delivery device according to claim 1 , wherein the medicament delivery device comprises a medicament.
13 . A method of preparing a medicament delivery device for use, the method comprising: moving a needle cover in a proximal direction from an extended position, in which the needle cover extends from a distal end of a housing and covers a distal end of a needle, to a retracted position, in which the needle cover is located in a proximal position relative to the extended position such that the needle protrudes from a distal end of the needle cover, to compress a needle cover biasing member located within the needle cover, and causing the needle cover biasing member to transition to a buckled state to reduce a hold force required for counteracting a restoring force of the needle cover biasing member, wherein when the needle cover biasing member is compressed yet before the needle cover biasing member has transitioned from a non-buckled state into the buckled state, the needle cover biasing member is arranged substantially along an axis, wherein the axis is defined by a first end of the needle cover biasing member and a second end of the needle cover biasing member that is opposite to the first end, and the axis is parallel to and radially outward from a longitudinal axis of the needle.
14 . A method of locking a medicament delivery device after medicament has been dispensed from the medicament delivery device, the method comprising: moving a needle cover in a distal direction from a retracted position, in which a needle protrudes from a distal end of the needle cover, to an extended position, in which the needle cover extends from a distal end of a housing and covers a distal end of the needle, under a restoring force of a needle cover biasing member in a buckled state, wherein the needle cover biasing member is located within the needle cover, extending the needle cover such that the needle cover biasing member moves into a non-buckled state, and preventing proximal movement of the needle cover once the needle cover is in the extended position post-use, wherein when the needle cover biasing member is compressed yet before the needle cover biasing member has transitioned from the non-buckled state to the buckled state, the needle cover biasing member is arranged substantially along an axis, wherein the axis is defined by a first end of the needle cover biasing member and a second end of the needle cover biasing member that is opposite to the first end, and the axis is parallel to and radially outward from a longitudinal axis of the needle.

Description

TECHNICAL FIELD This application relates to a medicament delivery device. BACKGROUND Medicament delivery devices are used to deliver a range of medicaments. In some devices, the device must be held in a holding position at an injection site for a predetermined period of time, to ensure that the correct dose of medicament is dispensed from the device, before removing the device from the injection site. It may be difficult to hold the device in the holding position whilst the medicament is dispensed. This may result in pain, discomfort, a wet injection site, early device removal and/or partial delivery of the medicament. The present disclosure provides an improved medicament delivery device. SUMMARY According to a first aspect of the present disclosure, there is provided a medicament delivery device comprising a housing comprising a proximal end and a distal end, a needle and a needle cover, wherein the needle cover is axially movable between an extended position, in which the needle cover extends from the distal end of the housing and covers a distal end of the needle, and a retracted position, in which the needle cover is located in a proximal position relative to the extended position such that the needle protrudes from a distal end of the needle cover, a needle cover biasing member configured to bias the needle cover axially in the distal direction towards the extended position, wherein the needle cover biasing member is configured to transition from a non-buckled state to a buckled state during proximal movement of the needle cover from the extended position to the retracted position. One advantage of the needle cover biasing member buckling when the needle cover biasing member is compressed during movement of the needle cover from the extended position to the retracted position is that the biasing force provided by the needle cover biasing member in its buckled state is reduced compared to the biasing force provided by the needle cover biasing member in its non-buckles state for the same displacement. Therefore, the force against which a user must hold the medicament delivery device during use is reduced. This may be particularly advantageous for users that lack strength to hold a medicament delivery device against the force of a needle cover biasing member for longer periods of time. In some embodiments, the needle cover biasing member may be is configured to elastically buckle from the non-buckled state to the buckled state. In some embodiments, when the needle cover is in the retracted position, the needle cover biasing member in the buckled state may be configured to provide a restoring force to move the needle cover to the extended state once a compressive force on the needle cover is removed. Thus, the needle cover biasing member may return to its original unbuckled state. The return to the unbuckled state may allow the medicament delivery device to still be operated if the needle cover is accidentally moved proximally without insertion of the needle. Furthermore, the return of the needle cover biasing member to its unbuckled state when the compressive force on the needle cover is removed allows the needle cover to recover the needle to prevent accidental contact with the needle after use. In some embodiments, the needle cover biasing member may be configured to transition to the buckled state once the needle cover has travelled over 50% of the distance from the extended position to the retracted position. Thus, the medicament delivery device may be designed such that moving the needle cover proximally to insert the needle into an injection site may still require such force that accidental needle contact is not possible, and that the holding force required to counteract the needle cover biasing force is sufficiently reduced once the needle cover has travelled over 50% of the distance. The distance at which the needle cover biasing member moves to the buckling state may coincide with needle insertion. It will be appreciated, that in some embodiments, the needle cover biasing member may move to the buckled state when the needle cover has travelled over 40%, or over 30%, or over 20% of the distance from the extended position to the retracted position. The force profile required to insert the needle may be the same as in known devices and then less than known devices after the needle is inserted and the needle cover biasing member buckles. In some embodiments, the needle cover may comprise a flange located proximate the distal end of the needle cover, the needle cover biasing member may be mounted on its distal end to the flange and the opposing proximal end may be mounted to a mount proximate the distal end of the housing. Thus, the length of the needle cover biasing member, and thus diameter, of the needle cover biasing member can be kept relatively small. This reduces the size of the needle cover biasing member and space required in the medicament delivery device to house the needle cover biasing m