A high pressure delivery device (100) for delivering a medicament includes a first chamber (111) for storing a supply of the medicament and a second chamber (121) in fluid communication with the first chamber (111). A fluid connection path (141) is in fluid communication with the second chamber (121) for administering the medicament. A valving system (131) is in fluid communication with the first chamber (111), the second chamber (121) and the fluid connection path (141). The valving system (131) allows a dose of the medicament to be injected from the first chamber (111) into the second chamber (121) while substantially preventing backflow of the dose into the first chamber (111) and substantially preventing leakage through the fluid connection path (131). The valving system (131) also allows the dose in the second chamber (121) to be administered through the fluid confection path (141) while substantially preventing the dose from flowing back into the first chamber (111).
