Abstract: An injector device for injecting or transferring a pharmaceutical product from a pharmaceutical cartridge. The injector device includes an injector body having a side wall having a proximal end portion and a distal end portion, the side wall having an inner surface and an outer surface, the inner surface of the side wall defining a space for receiving at least a portion of a body of a pharmaceutical cartridge therein. One or more retention members are disposed on the outer surface of the body. The injector device further includes a plunger rod having a proximal end portion and a distal end portion, the distal end portion of the plunger rod having a connection member constructed for connection to a connecting member mounted on a piston associated with a cartridge. The plunger rod has one or more receiving members formed about its length.