A high pressure delivery device for delivering a medicament includes a first chamber for storing a supply of the medicament and a second chamber in fluid communication with the first chamber. A fluid connection path is in fluid communication with the second chamber for administering the medicament. A valving system is in fluid communication with the first chamber, the second chamber and the fluid connection path. The valving system allows a dose of the medicament to be injected from the first chamber into the second chamber while substantially preventing backflow of the dose into the first chamber and substantially preventing leakage through the fluid connection path. The valving system also allows the dose in the second chamber to be administered through the fluid connection path while substantially preventing the dose from flowing back into the first chamber.
