Medicament delivery devices for administration of a medicament within a prefilled syringe

An apparatus, comprising:

• a prefilled syringe assembly including a syringe body, a needle staked to the syringe body, and an elastomeric member disposed within the syringe body, the syringe body including a flange;
• a piston member having a distal end configured to move within the syringe body between a first position and a second position to convey a dose of a medicament from the syringe body through the needle during an injection event;
• an actuator operably coupled to the piston member, movement of the actuator causing a force to be exerted on a proximal end of the piston member to move the distal end of the piston member within the syringe body;
• a syringe enclosure defining an internal volume within which a proximal end portion of the prefilled syringe assembly is disposed before and during the injection event, a distal end portion of the prefilled syringe assembly extending beyond a distal end surface of the syringe enclosure, a proximal end portion of the syringe enclosure including a first stop surface and a second stop surface, the first stop surface configured to limit distal movement of the piston member within the syringe body when the piston member has reached the second position during the injection event, the second stop surface configured to engage a proximal surface of the flange to limit movement of the prefilled syringe assembly within the syringe enclosure;
• and
• a case configured to contain the syringe enclosure and the prefilled syringe assembly, the case limiting movement of the actuator when the syringe enclosure is within the case, the syringe enclosure and the prefilled syringe assembly configured to be removed from within the case to allow movement the actuator.