A cartridge or ampoule syringe comprising a cartridge 102 provided with a sealing element, preferably a septum 112, to seal its distal end and to define a medicament chamber 104. The syringe additionally comprises a double ended cannula or needle 128； one of the ends 128a being for the delivery of a medicament and the other 128b being for the piercing of the sealing element 112. A removable cap 18 is also provided. In use the syringe is switchable from a starting configuration in which the septum piercing end of the needle 128b is spaced from the sealing element 112, to an activated configuration in which the piercing end of the needle 128b pierces the sealing element 112 to connect the medicament chamber 104 to the needle 128. To prevent accidental activation of the device the cap 118 further comprises at least one blocking formation 150, preferably a rib or a leg, that cooperates with a throat 118 which is provided as a part of the cartridge assembly for limiting relative movement between the piercing end of the needle 128b and the cartridge assembly, thereby to keep the device in the starting configuration when the cap 118 is in place.
