[Development of a novel liquid injection system].

A liquid jet injector employs compressed gas or spring to produce a high-velocity stream to deliver liquid drug into human body through skin. There are many clinical jet injection products available, none of which is domestic. A new liquid jet injector is designed based on a comprehensive analysis of the current products. The injector consists of an ejector, trigger and a re-positioning mechanism. The jets characteristics of sample injector are tested, and the results show that the maximum exit pressure is above 15 MPa, a threshold value for penetrating into the skin.

[The evaluation of mechanical performance of a jet injection system].

In this study, the mechanical properties of a self-made jet injector and a foreign product are tested from three aspects: penetration ability, injection completeness and injection dispersion. Correspondingly, three different experiments are designed and performed: dynamic pressure measurement, injection into silicon rubbers with fixed hardness yet different thickness and injection into polyacrylamide gels with fixed hardness. The results show similar mechanical properties between self-made system and the foreign system. The evaluation of the mechanical performance of jet injectors that consists of penetration ability, injection completeness and injection dispersion can describe the jet injection process effectively.