Abstract: An automatic needle-free injector container unit system is provided. The system comprises a needle-free injector for injecting a medicament from a cartridge to a user, such as a human or small pet, wherein the needle-free injector comprises a cartridge chamber for receiving the cartridge; and an injector movement mechanism for automatically and reversibly positioning the needle-free injector to one or more of: a home position where injector is retracted and positioned away from contact with the user, and an injecting position where the injector is in proximity? to the user for injection of the medicament; and a container for housing the needle-free injector and injector movement mechanism. One or more sensors may also be provided to facilitate the injection process. The system may be a portable unit and located, remotely from medical facilities, and controlled locally and/or remotely by a user with a computer interface.

Abstract: A needle-free injector, and method of using said injector, for injecting variable, discrete doses of liquids intradermally or transdermally into a subject in need thereof, are provided. The injector comprises a barrel having a front section, an intermediate section and a rear section; and a cap having a rear end connectable to the front section of the barrel and rotatable about the front section of the barrel, the cap having a discharge end for receiving a cartridge containing the liquid to be injected, wherein rotation of the cap about a longitudinal axis of the front section of the barrel adjusts the dose of liquid to be discharged from the cartridge by the injector in iscrete dose units. A piston cap is also provided for adjusting the force of the impact of an injector piston on a plunger on the cartridge.

Abstract: A needleless injector syringe includes a tubular barrel containing a first chamber for receiving a liquid, a nozzle on a front end of the barrel, a piston which drives a plunger for discharging the liquid through the nozzle, a second chamber in which the piston slides, a third chamber in fluid communication with the second chamber for receiving gas from said second chamber during forward movement of the piston, and for carrying gas to the second chamber to cause the piston to retract, and a breach plug closing a rear end of the barrel for directing gas under pressure alternately against the rear end of the piston and to the third chamber for driving the piston between the discharge position and a retracted position.

Abstract: A needleless injector syringe includes a tubular barrel containing a first chamber for receiving a liquid, a nozzle on a front end of the barrel, a piston which drives a plunger for discharging the liquid through the nozzle, a second chamber in which the piston slides, a third chamber in fluid communication with the second chamber for receiving gas from said second chamber during forward movement of the piston, and for carrying gas to the second chamber to cause the piston to retract, and a breach plug closing a rear end of the barrel for directing gas under pressure alternately against the rear end of the piston and to the third chamber for driving the piston between the discharge position and a retracted position.