Abstract: A needleless, low pressure, air powered medicine injector with a quick disconnect medicine delivery assembly removably connected to the injector housing. Low pressure air drives a biased piston through a discharge stroke, beginning from the retracted position into the medicine chamber, thereby forcing medicine through a one-piece nozzle. A removable chamber filling mechanism connected to the housing is coupled to the medicine chamber through fill ports, such that the medicine chamber is filled utilizing a positive pressure medicine distributor. A movable spacer collar positioned in front of the nozzle provides an air gap between a patient's skin and the one-piece nozzle. A safety interlock coupled to an activating mechanism and the chamber filling mechanism prevents unwanted discharge of the injection.