Auto-injectors for administration of a medicament within a prefilled syringe
An apparatus includes a housing, a carrier, and an expandable assembly. The housing defines an opening configured to selectively place a gas chamber of the housing in fluid communication with an exterior volume. The carrier is movably disposed within the housing and is coupled to a medicament container. A proximal surface of the carrier defines a portion of a boundary of the gas chamber. The expandable assembly has a first member and a second member. The first member is coupled to an elastomeric member disposed within the medicament container, and the second member includes a valve portion. The expandable assembly transitions from a collapsed configuration to an expanded configuration when the elastomeric member moves within the medicament container. The valve portion moves relative to the opening when the expandable assembly transitions from the first to the second configuration, placing the gas chamber in fluid communication with the exterior volume.
1 . An apparatus, comprising:
a housing having a housing length along a longitudinal axis;
an energy storage member disposed within the housing, the energy storage member configured to produce a force when the energy storage member is actuated;
a medicament container disposed within the housing, the medicament container having an elastomeric member disposed therein, the medicament container coupled to a needle, the medicament container having a container length;
a carrier coupled to the medicament container, the carrier configured to move from a first carrier position to a second carrier position in response to the force produced by the energy storage member such that the needle moves from a first needle position, in which the needle is disposed within the housing, to a second needle position, in which a portion of the needle extends from the housing, wherein the elastomeric member configured to move within the medicament container from a first position to a second position to convey a medicament from the medicament container when the carrier is in the second carrier position; and
a ratio of the housing length to the container length being less than about 1.5.
2 . The apparatus of claim 1 , wherein:
the carrier moves from the first carrier position to the second carrier position by a carrier travel distance;
the elastomeric member is configured to move a stroke distance within the medicament container to convey the medicament; and
a ratio of the housing length to a sum of the container length, the carrier travel distance, and the stroke distance is less than about 1.
3 . The apparatus of claim 1 , wherein:
the housing includes a first stop surface and a second stop surface, the first stop surface configured to limit proximal movement of the carrier when the carrier is in the first carrier position, the second stop surface configured to limit distal movement of the carrier when the carrier is in the second carrier position.
4 . The apparatus of claim 1 , wherein:
the housing defines a gas chamber;
the energy storage member is configured to produce a pressurized gas within the gas chamber;
a proximal surface of the elastomeric member defines a first portion of a boundary of the gas chamber; and
a proximal surface of the carrier defines a second portion of the boundary of the gas chamber.
5 . The apparatus of claim 4 , wherein:
an outer surface of the carrier includes a seal in sliding contact with an inner surface of the housing, the seal fluidically isolating the gas chamber from an exterior volume.
6 . The apparatus of claim 4 , wherein a side wall of the housing defines an opening configured to selectively place the gas chamber in fluid communication with an exterior volume, the apparatus further comprising:
a gas vent assembly having a first member and a second member, the first member coupled to the elastomeric member, the second member coupled within the opening, the first member of the gas vent assembly configured to move with the elastomeric member such that the second member moves relative to the opening to fluidically couple the gas chamber with the exterior volume when the elastomeric member is in the second position.
7 . The apparatus of claim 6 , wherein:
the gas vent assembly is configured to transition from a collapsed configuration to an expanded configuration when the elastomeric member moves within the medicament container.
8 . The apparatus of claim 7 , wherein:
the second member includes a valve portion, the valve portion is configured to move relative to the opening when the gas vent assembly transitions from the collapsed configuration to the expanded configuration to place the gas chamber in fluid communication with the exterior volume.
9 . The apparatus of claim 8 , wherein:
the valve portion of the second member defines a gas release path, the valve portion disposed within the opening of the housing such that the gas release path is fluidically isolated from the gas chamber via a seal member when the gas vent assembly is in the collapsed configuration.
10 . The apparatus of claim 7 , wherein:
the gas vent assembly has a first length when in the collapsed configuration and a second length when in the expanded configuration; and
a ratio of the second length to the first length is greater than about 2.0.
11 . The apparatus of claim 7 , wherein:
the elastomeric member is configured to move a stroke distance within the medicament container in response to the pressurized gas being within the gas chamber; and
the gas vent assembly has a first length when in the collapsed configuration, a ratio of the first length to the stroke distance being less than about 1.2.
12 . The apparatus of claim 7 , wherein:
a length of the gas vent assembly when in the expanded configuration is configured to set a dosage amount.
13 . An apparatus, comprising:
a housing having a housing length along a longitudinal axis;
an energy storage member disposed within the housing, the energy storage member configured to produce a force when the energy storage member is actuated;
a medicament container disposed within the housing, the medicament container having an elastomeric member disposed therein, the medicament container coupled to a needle, the medicament container having a container length;
a carrier coupled to the medicament container, the carrier configured to move from a first carrier position to a second carrier position by a carrier distance in response to the force produced by the energy storage member such that the needle moves from a first needle position, in which the needle is disposed within the housing, to a second needle position, in which a portion of the needle extends from the housing, wherein the elastomeric member configured to move within the medicament container through a stroke distance to convey a medicament from the medicament container when the carrier is in the second carrier position; and
a ratio of the housing length to a sum of the container length, the carrier distance, and the stroke distance is less than about 1.
14 . The apparatus of claim 13 , further comprising:
a release mechanism configured to release the force from the elastomeric member after the elastomeric member has been moved within the medicament container through the stroke distance.
15 . An apparatus, comprising:
a housing defining a gas chamber, the housing having a housing length along a longitudinal axis;
an energy storage member disposed within the housing, the energy storage member configured to produce a pressurized gas within the gas chamber;
a first medicament container assembly disposed within the housing, the first medicament container assembly including a first container body and a first elastomeric member disposed within the first container body, the first medicament container assembly including a first needle coupled to a distal end portion of the first container body, the first medicament container assembly configured to move within the housing in response to a force exerted by the pressurized gas such that the first needle moves from within the housing to an exterior volume outside of the housing, the first elastomeric member configured to move within the first container body to convey a first medicament contained therein in response to the force, the first medicament container assembly having a container length;
a second medicament container assembly disposed within the housing, the second medicament container assembly including a second container body and a second elastomeric member disposed within the second container body, the second medicament container assembly including a second needle coupled to a distal end portion of the second container body, the second medicament container assembly configured to move within the housing in response to the force such that the second needle moves from within the housing to the exterior volume, the second elastomeric member configured to move within the second container body to convey a second medicament contained therein in response to the force; and
a ratio of the housing length to the container length being less than about 1.5.
16 . The apparatus of claim 15 , wherein:
the first medicament container assembly is non-coaxial with the second medicament container assembly.
17 . The apparatus of claim 15 , further comprising:
a carrier coupled to the first medicament container assembly, the carrier configured to move from a first carrier position to a second carrier position in response to the force produced by the energy storage member, wherein:
the first elastomeric member is configured to move within the first medicament container assembly from a first position to a second position when the carrier is in the second carrier position,
the carrier moves from the first carrier position to the second carrier position by a carrier distance,
the first elastomeric member is configured to move a stroke distance within the first container body to convey the first medicament, and
a ratio of the housing length to a sum of the container length, the carrier distance, and the stroke distance is less than about 1.
18 . The apparatus of claim 15 , further comprising:
a release mechanism configured to release at least a portion of the force from the first elastomeric member and the second elastomeric member after the first elastomeric member has been moved within the first container body a predetermined distance and the second elastomeric member has been moved within the second container body the predetermined distance.
19 . The apparatus of claim 18 , wherein:
a side wall of the housing defining an opening configured to selectively place the gas chamber in fluid communication with the exterior volume; and
the release mechanism has a first member, a second member, and a third member, the first member coupled to and configured to move with the first elastomeric member, the second member coupled to and configured to move with the second elastomeric member, the third member coupled to the first member and the second member, the third member configured to move relative to the opening to fluidically couple the gas chamber with the exterior volume when each of the first elastomeric member and the second elastomeric member move the predetermined distance.
20 . The apparatus of claim 15 , wherein the energy storage member is disposed between the first medicament container assembly and the second medicament container assembly within the housing.