Abstract: A vial adapter for a needle-free injection syringe and methods of filling a needle-free syringe from a vial of injectable fluid. One vial adapter embodiment includes a housing and a compliant valve. The housing includes a central divider located between a vial opening and a needle-free syringe opening. The housing also includes a hollow center post extending from the central divider toward the needle-free syringe opening and a hollow filling needle extending from the central divider toward the vial opening. Together, the filling needle and center post provide for fluid communication between the vial opening and the needle-free syringe opening. The compliant valve includes a surface forming a fluid tight seal with the central divider and an inner passageway. In addition, a syringe sealing surface provides for a fluid tight seal with a needle-free syringe placed into contact with the compliant valve.

Abstract: A needle-free injection device having an outer housing and an inner housing is disclosed. The inner housing is configured to receive a needle-free syringe in one end. In addition, the inner housing is movable within the outer housing between a syringe loading position and a firing position. The device also includes an activation button operatively associated with the inner and outer housings and a housing lock engaged by the activation button to prohibit movement of the inner housing from the syringe loading position to the firing position when the activation button is activated with the inner housing in the syringe loading position. Methods and apparatus for using, filing and operating the needle-free injection device are also disclosed.