a needle - free injector device comprising a latch having a safe position which disables the triggering of the device , and a ready position which restrains movement of a dispensing member but enables triggering and a triggered position which permits movement of the dispensing member is disclosed . an additional safety mechanism blocks the triggering of the device until removed . a cap is provided to maintain the sterility and stability of the drug formulation and is configured such that the cap removal is required prior to placing the device in a ready to trigger state .