A medical injector (300) includes a medicament container (310), a non-manual actuator (320), and an adapter (340) for coupling the medicament container (310) and the non-manual actuator (320). The adapter (340) includes a proximal end portion (341) configured to engage a drive element (326) of the non-manual actuator (320). The adapter (340) also includes a distal end portion (344) including a surface (345) configured to engage a movable element (319) within the medicament container (310). The adapter (340) may include a coupler (350) having at least one coupling member (353) configured to removably couple the adapter (340) to the medicament container (310), and also having a connector (354) configured to removably couple the adapter (340) to the non-manual actuator (320). The drive element (326) of the non-manual actuator (320) may apply a movement force to the adapter (340), which then pushes the movable element (319) within the medicament container (310) to inject medicament into a patient.
