Our study has shown that the detonation wave energy in a hydrogen–air mixture can be transferred to the liquid and accelerate it up to velocities on the order of 70 m/s, and the penetration of the streamlet of liquid in the model medium to a distance of 15 mm is observed. The use of gas detonation makes it possible to replace the less effective source of energy for acceleration of the medicinal preparation in needle-free injection devices by gas mixtures. This will make it possible to simplify the needle-free injection devices and reduce their price, as well as to avoid ejection of poisonous byproducts of solid fuel combustion.