Provided is a cassette unit suitable for use with an auto-injector having an electrically powered drive unit. The cassette unit has a housing defining a cassette unit housing cavity and a needle projection aperture. The housing cavity is arranged for receipt of a syringe suitable for delivery of a drug to a patient. The syringe has a barrel for containing a volume of a liquid drug formulation, the barrel defining a flange at the rear end thereof and a forward shoulder at the forward end thereof. The cassette unit includes one or more shoulder support features for supporting the forward shoulder of the syringe. In use, the one or more shoulder support features act to direct a major part of an applied load path to travel through the shoulder at the forward end of the syringe and lesser load to pass through the flange at the rear end thereof.
