Auto-injector

A cassette unit for use with an auto-injector having a drive unit, said cassette unit comprising:

• a cassette unit housing defining a cassette unit housing cavity, a rearward entrance to said cavity and a forward needle projection aperture;
• said cassette unit housing cavity in receipt of a syringe comprising:
• a barrel for containing a volume of a liquid drug formulation, said barrel defining a flange at the rear end thereof and a forward shoulder at the forward end thereof;
• a hollow needle at a front end of said barrel, said hollow needle defining a needle tip for dispensing of said liquid drug formulation;
• and
• a plunger that is axially movable within the barrel;
• and
• in capping relationship with said rearward entrance of the cassette unit housing, a cassette unit end-cap, said cassette unit end-cap defining a drive rod-receiving opening for receipt of a drive rod for providing forward axial drive to said plunger;
• and
• a biasing element defining a biasing relationship between the cassette unit end-cap and the flange of the syringe, thereby urging the syringe forwards in relation to the cassette unit end-cap;
• and
• a damping element defining a damping relationship between the cassette unit end-cap and the flange of the syringe, thereby acting to damp rearward movement of the syringe relative to the cassette unit end-cap.