Device and method for delivering a medicament

Patent metadata

Field	Value
Publication number	US-2016361503-A1
Application number	US-201515116418-A
Country	US
Kind code	A1
Filing date	Mar 3, 2015
Priority date	Mar 6, 2014
Publication date	Dec 15, 2016
Grant date	—

Abstract

A device for delivery of medicament is presented that has an elongated housing, a container mounted within the housing and adapted to contain liquid medicament, a stopper slidably arranged within said container, and a delivery mechanism comprising a resilient member, a plunger assembly having one end connected to the stopper and a second end being operably connected to the resilient member, a rotatable latch for releasably retaining the plunger assembly in a first position where the resilient member has an accumulated energy, where rotation of the latch releases the plunger assembly such that the accumulated energy is transferred to the plunger assembly for driving the stopper within the container whereby the medicament within said container is delivered to an injection site. After delivery of the medicament a rotator having a hard stop feature aligns with a rib on the protective shield to prevent retraction of the protective shield.

First claim

1 . A device for delivery of medicament, comprising:
an elongated housing having a proximal end and a distal end; a container mounted within the housing and having a slidable stopper contained within and configured to contain a liquid medicament; a non-rotating plunger assembly comprising a plunger rod having a proximal end and a distal end that is in contact with the stopper, an indent and a longitudinal groove, where the plunger assembly is configured to move axially relative to the housing from a ready position and to an end-of-injection position; a non-rotating protective shield axially slidable with respect to the housing having an outer surface comprising a longitudinal rib terminating in a bearing surface, where the protective shield has a proximally extending beam and is configured to move from a partially extended position, to a retracted position and to a fully extended position; a rotator configured as a cylindrical tube having an open distal end and a proximal end wall, where the rotator is axially fixed inside the housing and is rotated through engagement with the rib to form an irreversible lock to prevent the protective shield from moving when in the fully extended position; a coiled spring having a distal end fixed axially relative to the outer housing and a proximal end attached to the plunger assembly such that the coiled spring is in an extended partially uncoiled tensed configuration having accumulated energy when the plunger assembly is in a cocked position; a rotatable latch having a first position where the latch prevents the plunger assembly from moving axially and a second position where the latch is disengaged from the plunger assembly to allow the plunger to axially move distally relative to the latch, the rotator and the outer housing such that the accumulated energy is transferred to the plunger rod for driving the plunger rod and the stopper a predetermined axial distance within the container whereby the medicament within said container is delivered.

2 . The device of claim 1 wherein the proximal end of the housing comprises a window that allows a user to visually observe a scrolling tape that moves during the delivery of the medicament.

3 . The device of claim 1 wherein the spring is a variable force spring comprising a coiled band configured to move from an uncoiled tense state to a coiled relaxed state.

4 . The device of claim 3 wherein the variable force spring comprises two or more springs arranged in a laminate configuration or side-by-side configuration.

5 . The device of claim 1 further comprising a latch carrier axially fixed to the housing, where the latch is rotatably positioned in the latch carrier and the latch carrier has a through hole to allow passage of the proximally extending beam on the protective shield as the protective shield moves in a proximal direction.

6 . The device of claim 1 wherein the rotator has a longitudinal channel on an inside surface configured to accept axial movement of the rib.

7 . The device of claim 5 wherein the proximal end wall of the rotator has through hole to allow the beam to pass through and engage the latch.

8 . The device of claim 5 wherein the proximal end wall of the rotator has a circumferentially arranged ratchet teeth configured to engage a flexible tooth on the latch carrier such that the engagement of the ratchet teeth with the flexible tooth creates a second biasing force urging the rotator to rotate from a first to a second position.

9 . The device of claim 5 wherein the channel has straight and angled side walls configured to engage the rib when the rib moves in the proximal direction such that engagement of the bearing surface of the rib with the angled sidewall imparts a first biasing force that causes the rotator to rotate relative to the housing to a first position where the flexible tooth partially indexes from one ratchet tooth to an adjacent ratchet tooth.

10 . The device of claim 5 wherein the channel has a hard stop that is configured to engage the bearing surface of the rib to create an irreversible lock to prevent axial movement of the protective shield when in the fully extended position.

11 . The device of claim 5 wherein the latch has a cam configured to engage a bearing surface on a proximal end of the beam.

12 . The device of claim 11 wherein the cam is configured with a cam angle such that proximal axial movement of the beam when engaged with the cam causes the latch to rotate from the first position to the second position.

13 . The device of claim 1 wherein the latch has an inwardly projecting protrusion configured to engage an indent on the plunger rod when the latch is in the first position to prevent axial movement of plunger relative to the housing.

14 . The device of claim 13 wherein the plunger rod has a longitudinal groove configured to accept the protrusion when the latch is in the second position.

15 . The device of claim 1 where the protective shield is connected to a biasing element that urges the protective shield to move distally such that a portion of the shield protrudes from the distal end of the housing when the plunger assembly is in the ready position.

16 . The device of claim 1 wherein the housing further comprises a clicker mechanism that generates an audible sound during the delivery of the medicament.

17 . The device of claim 16 wherein the clicker mechanism comprises a clicker arm on the plunger assembly that engages teeth on a clicker track that is axially fixed relative the outer housing.

18 . A method of performing an injection comprising, in combination, the following steps,
a) placing a protective shield at an injection site, where the protective shield is partially extended from a distal end of a housing of an auto-injector; b) pushing the housing in a distal direction to retract the protective guard into the housing to a fully retracted position, where the protective guard has a beam projecting proximally and a longitudinal rib on an outside surface that engages a channel on a rotator that is axially fixed to the housing; c) engaging the beam with a rotatable latch when the protective guard is in the fully retracted position causing the latch to rotate and unlock a plunger rod; d) coiling a variable force spring attached to the plunger rod to axially move the plunger rod distally where it engages a slidable stopper in a container of medicament to deliver the medicament by injection into the injection site; e) extending the protective shield to a fully extended locked position when moving the housing proximally from the injection site and; and f) rotating the rotator to align the rib with a hard stop on the rotator when the protective shield is in the extended locked position to prevent retraction of the protective shield into the housing.

19 . The method of claim 18 where the variable force spring has at least two different force profiles, where the force profile increases as the variable force spring coils.

20 . The method of claim 18 where engagement of the rib with the channel rotates the rotator relative to the housing partially indexing a ratchet engagement between the rotator and a rotatably fixed latch carrier.

Assignees

• Carebay Europe Ltd

Inventors

• Bendek Antonio
• Giambattista Lucio

Classifications

• A61M2005/3126

  Specific display means related to dosing · CPC title

• A61M2005/2013

  triggering of discharging means by contact of injector with patient body · CPC title

• A61M2005/3267

  Biased sleeves where the needle is uncovered by insertion of the needle into a patient's body · CPC title

• A61M2005/3247

  Means to impede repositioning of protection sleeve from needle covering to needle uncovering position · CPC title

• A61M5/3245 Primary

  Constructional features thereof, e.g. to improve manipulation or functioning · CPC title