Patent ID: 7503907

Claim:
An injector, comprising: a medicament cartridge comprising: a medicament; a tube having first and second ends and a lumen with a longitudinal axis for retaining the medicament therein; a needle fixed in a hub received within the tube, such that the needle is operatively associated with the second end of the tube, the needle having a piercing end extending into the lumen; a first stopper located at a first position near the second end moveable within the lumen along the longitudinal axis, the first stopper having a proximal portion in sealing contact against the tube in the lumen and a distal portion protruding distally from the proximal portion and spaced from tube in the lumen, the distal portion being disposed and configured to be pierced by the piercing end of the needle and to be received within the hub when pierced by the piercing end of the needle; and a second stopper within and against the tube in the lumen located at a second position near the first end moveable within the lumen along the longitudinal axis, wherein movement of the first stopper with respect to the tube from the first position toward the needle causes the piercing end of the needle to pierce the first stopper to create a fluid pathway for the medicament through the needle, and movement of the second stopper with respect to the tube from the second position toward the second end of the tube compresses the medicament held between the second stopper and the first stopper so that the medicament is expelled through the fluid pathway; wherein the injector is a jet injector.