The US Department of Veterans Affairs recognized for the first time that a veteran acquired Hepatitis C from his military jet injections and awarded service-connection for his disability. In practice this is a position between a point in the convergence 5 ′ where the pressure has reduced enough to a point in the nozzle bore 3 far enough upstream to give the particles adequate residence time in the nozzle to achieve the desired velocity. FDA warns public and health care professionals not to use needle-free devices for injection of dermal fillers.

Samir Mitragrotri visually captured splash-back after discharging a multi-use nozzle jet injector using high-speed microcinematography.This sonic nozzle 4 is provided with an aperture which forms a first convergence or constriction 5 to the flow of gas through the main body 1 . It is enough that the gas flow path has started to converge at the position where the particle inlet passage 10 is located such that there is a reduction in pressure sufficient to draw in the particles. October 2017: A group of scientists publishes an academic study in the Journal of Biomedical Optics, about a new jet injection technique of jet injection by continuous-wave laser cavitation aimed to "develop a needle-free device for eliminating major global healthcare problems caused by needles". the cassette 50 can then be mounted on the syringe with one or other of its radial throughholes 53 aligned with the syringe's particle inlet passage leading to the particle entrainment chamber 8 .

In addition, it may be desirable to include a charged lipid and/or detergent in the pharmaceutical compositions.the convergence 5 ′ causes a reduction in gas pressure, in use, due to the Venturi effect such that there is, in use, a pressure differential across the powder cavity 55 . Similarly, the particle inlet passage 10 may be located downstream of the chamber 8 either at the second convergence 9 or downstream thereof in the nozzle bore 3 . Vented spacers were fitted to the end of the device nozzle so as to keep the devices at a fixed distance from the target surface and at right angles to it. Preferably, the device is so constructed and arranged that substantial boundary layer separation between the wall of the nozzle and the gas jet is avoided thus enabling the particles accelerated out of the exit nozzle in the gas jet to be distributed across substantially the full width of the nozzle's downstream exit. skin or mucosa) positioned in close proximity to the nozzle exit, the size of the target area impacted by the particles will be generally equal to the size of the bore 3 at the downstream exit of the nozzle 2 and the particles will be well distributed across the target area.