Auto-injector
Auto-injector for administering a dose of a liquid medicament includes a housing to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament, the housing having a distal end and a proximal end with an orifice to apply against an injection site. A spring means, upon activation, can push the needle from inside the housing through the orifice and past the proximal end, operate the syringe to supply the dose of medicament, and retract the syringe with the needle after delivering the medicament. An activating means can lock the spring means in a pressurized state prior to manual operation and capable of, upon manual operation, releasing the spring means for injection.
1. An auto-injector, comprising:
a housing configured to receive a medicament container, the medicament container containing a medicament;
a stopper movable in a proximal direction relative to the medicament container to dispense the medicament from the medicament container;
a container carrier configured to be disposed within the housing, the container carrier having a proximal end region configured to engage a proximal portion of the medicament container, the container carrier and the medicament container being configured such that a distal portion of the medicament container extends distally beyond a distal end of the container carrier and a distal flange of the medicament container is distally spaced apart from the container carrier while the proximal end region of the container carrier is engaged with the proximal portion of the medicament container;
a plunger configured to displace the stopper in the proximal direction relative to the medicament container when the medicament container and the container carrier are disposed in the housing;
a drive spring disposed within the housing, the plunger being biased in the proximal direction relative to the housing by a proximally-directed force of the drive spring;
an actuation element configured to rotate about an axis relative to the housing, the actuation element comprising an angled surface;
a needle sleeve slidably disposed within the housing and comprising a protrusion configured to engage the angled surface of the actuation element, the needle sleeve configured to slide axially relative to the housing from (i) a proximal position in which the needle sleeve extends proximally beyond a proximal end of the housing and a flexible arm holds the plunger in a distal position relative to the housing against the proximally-directed force of the drive spring to (ii) a distal position in which the protrusion of the needle sleeve has moved along the angled surface of the actuation element, the actuation element has rotated about the axis relative to the housing and the flexible arm, and the flexible arm has outwardly deflected to release the plunger from being held in the distal position relative to the housing against the proximally-directed force of the drive spring; and
a needle sleeve spring configured to axially bias the needle sleeve in the proximal direction,
wherein the drive spring is configured to translate the plunger to a proximal position relative to the housing to displace the stopper in the proximal direction to dispense the medicament from the medicament container after the flexible arm has outwardly deflected.
2. The auto-injector of claim 1 , wherein the container carrier comprises (i) an inwardly angled protrusion located on the proximal end region that is configured to engage the proximal portion of the medicament container and (ii) an outward protrusion located on a distal portion that extends outward from an outer surface of the container carrier.
3. The auto-injector of claim 2 , wherein the outward protrusion is configured to couple the container carrier to a portion of the housing to limit axial movement of the container carrier relative to the housing.
4. The auto-injector of claim 1 , comprising a spring support element disposed within the housing.
5. The auto-injector of claim 4 , wherein the spring support element has a first state in which distal movement of the spring support element relative to the housing is limited and a second state in which distal movement of the spring support element relative to the housing is allowed.
6. The auto-injector of claim 5 , wherein the auto-injector is configured to cause the spring support element to change from the first state to the second state when the plunger is in the proximal position.
7. The auto-injector of claim 6 , wherein the stopper is in a proximal-most position within the medicament container when the plunger is in the proximal position.
8. The auto-injector of claim 1 , wherein the medicament container contains a single dose of the medicament.
9. The auto-injector of claim 1 , wherein the medicament comprises a protein.
10. An auto-injector, comprising:
a housing configured to receive a medicament container, the medicament container containing a medicament;
a stopper movable in a proximal direction relative to the medicament container to dispense the medicament from the medicament container;
a container carrier configured to be disposed within the housing, the container carrier having a proximal end region configured to engage a proximal portion of the medicament container, the container carrier and the medicament container being configured such that a distal portion of the medicament container extends distally beyond a distal end of the container carrier and a distal flange of the medicament container is distally spaced apart from the container carrier while the proximal end region of the container carrier is engaged with the proximal portion of the medicament container;
a plunger configured to displace the stopper in the proximal direction relative to the medicament container when the medicament container and the container carrier are disposed in the housing;
a drive spring disposed within the housing, the plunger being biased in the proximal direction relative to the housing by a proximally-directed force of the drive spring;
an actuation element configured to rotate about an axis relative to the housing, the actuation element comprising an angled surface;
a needle sleeve slidably disposed within the housing and comprising a protrusion configured to engage the angled surface of the actuation element; and
a needle sleeve spring configured to axially bias the needle sleeve in the proximal direction,
wherein the drive spring is configured to translate the plunger to a proximal position relative to the housing to displace the stopper in the proximal direction to dispense the medicament from the medicament container after the actuation element has rotated relative to the housing.
11. A method comprising:
distally moving a needle sleeve relative to a housing of an auto-injector against a biasing force of a needle sleeve spring thereby (i) causing a protrusion of the needle sleeve to move along an angled surface of an actuation element to rotate the actuation element about an axis relative to the housing;
outwardly deflecting a resilient arm to release a plunger rod from being held in a distal position, the plunger rod being biased in a proximal direction by a proximally-directed biasing force of a compression spring; and
proximally moving the plunger rod relative to the housing and relative to a medicament container from the distal position to a proximal position by the proximally-directed biasing force of the compression spring after the resilient arm has been outwardly deflected to dispense a medicament from the medicament container, wherein an angled surface located at a proximal end of a container carrier is engaged with a proximal portion of the medicament container to limit proximal movement of the medicament container relative to the container carrier, a distal end of the medicament container extends distally beyond a distal end of the container carrier, and a distal flange of the medicament container is distally spaced apart from the container carrier.
12. The method of claim 11 , comprising distally moving a spring support element relative to the housing by a distally-directed biasing force of the compression spring when the plunger rod is in the proximal position, the spring support element having a surface coupled with a distal end of the compression spring.
13. The method of claim 12 , comprising limiting a distal movement of the spring support element relative to the housing until the plunger rod is in the proximal position by engaging an outward protrusion of the spring support element with a surface of the auto-injector.
14. The method of claim 13 , comprising distally moving the distal end of the compression spring relative to the housing by the distally-directed biasing force of the compression spring as the spring support element distally moves relative to the housing.
15. The method of claim 11 , wherein outwardly deflecting the resilient arm is performed after the needle sleeve has moved distally relative to the housing.
16. The method of claim 11 , wherein outwardly deflecting the resilient arm is performed after the actuation element has rotated about the axis relative to the housing.
17. The method of claim 11 , wherein the protrusion is in direct contact with the angled surface as the protrusion moves along the angled surface to rotate the actuation element about the axis relative to the housing and relative to the resilient arm.
18. The method of claim 11 , comprising coupling an outward protrusion of the container carrier to a portion of the housing to limit axial movement of the container carrier relative to the housing.
19. The method of claim 11 , wherein the medicament comprises a protein.
20. The method of claim 11 , wherein the medicament container contains a single dose of the medicament.