Auto injector with cassette

An auto injector for receiving a cassette with medicament and for administering the medicament, the auto injector comprising:

• a housing extending from a proximal end to an opposite distal end along a longitudinal direction and which defines a longitudinal axis, the housing including:
• a cassette covering section configured to extend to cover at least 10% of the cassette when received inside the housing, and
• a distal section extending from the cassette covering section;
• internal injector parts within the housing, wherein the distal section covers all internal injector parts, the internal injector parts including one or more cassette interacting parts adapted to lock the cassette inside the housing;
• and
• a cassette abutting surface adapted for directly abutting a distal surface of the cassette when the cassette is positioned inside the housing, the distal surface of the cassette being the most distal surface of the cassette, the cassette abutting surface defining a proximal end plane from where substantially no internal injector parts extend proximally prior to assembling the cassette and the housing.

A system comprising:

• a cassette including a syringe compartment containing medicament and extending from a proximal end to a distal end, wherein the proximal end is adapted for being in connection with a hollow needle through which the medicament is allowed to exit the syringe compartment, a stopper movable from a distal position to a proximal position inside the syringe compartment for emptying the syringe compartment, and a syringe holder extending around at least part of the syringe compartment;
• and
• an auto injector for removably receiving the cassette and for administering the medicament in the cassette to a patient, the auto injector including an auto injector housing extending from a proximal end to a distal end along a longitudinal direction and which defines a longitudinal axis, a piston adapted for proximal movement of the stopper in parallel with the longitudinal axis, and one or more cassette interacting parts adapted for engaging with and locking the cassette inside the auto injector housing and for facilitating administering of the medicament, a drive module adapted for moving the piston and the one or more cassette interacting parts in the proximal direction in parallel with the longitudinal axis of the housing, wherein after the cassette has been positioned in the housing, the one or more cassette interacting parts are configured for only moving in parallel with the longitudinal axis of the auto injector housing during locking of the cassette to the housing and during administration of the medicament, and
• wherein the stopper is movable by the piston for emptying the syringe compartment.