The dual-piston jet injector and the viability of drug delivery

Abstract

Drug delivery through jet-injection opens the doors to very rapid drug dispersion by eliminating the need for needle sterilization. With this comes the need for a continuous flow of fluids from a large reservoir, currently not available to the single-piston drug delivery systems. A two-piston system in a jet injector enables the use of a cyclic motion of pistons to drive the injected fluids, as opposed to the one-piston design that requires resetting the mechanism. This provides a way to dispense high-volume doses of medication without reloading. In order to test the feasibility of using a two-piston arrangement in jet-injected drug delivery, we have constructed a bench-top version to attempt to achieve the velocities and flow rates needed for jet injection. Using water as the injected fluid, we have found that driving the two pistons with 1800 out-of-phase, 80% symmetric, saw-tooth waveforms and a frequency of 10 Hz is sufficient to inject 900 pIUs of water through the jet and maintain a pressure of more than 2 MPa.