| Abstract | High speed liquid jets have been widely used and appropriately applied in many fields of engineering and technology, such as cutting, automobile combustion, and medical engineering. In medical engineering, a jet injector is a type of drug delivery device that uses a high-pressure narrow jet of the injection liquid instead of a hypodermic needle to penetrate the epidermis. Electromagnetic power or voice-coil, gas cartridge, and a compressed spring may be used as power sources.
This study aimed to investigate the characteristics of a needle-free jet injection or a jet injector device constructed as a prototype by the use of an air-powered injector that co-operated with a hydraulic power unit by the impact-driven method (IDM), called an IDM injector. This IDM injector was designed to match or be comparable with a commercial injector with the characteristics of exit jet velocity of 80-480 m/s, impact peak pressure of 10-80 MPa, and jet power of 0.3-3.3 kW. The behavior of the jets generated from the IDM injector was investigated by the use of a high speed video camera to capture the phenomena. It was found that the IDM injector was able to generate a jet as double pulse jet. After that, the delivery mechanism was investigated by injection into a simulant tissue, polyacrylamide gels, and was compared with that of a commercial injector, Cool.click. Results showed that the drug delivery of the IDM injector was able to be divided into two stages, the penetration stage and the injection with dispersion stages together. The delivery of the Cool.click injector was able to be divided into three stages, the erosion stage, the penetration stage, and the injection with dispersion stages together. Double pulse phenomena were similar between the experimental and computational fluid dynamics (CFD). Results showed similar formation phenomena and repeated pulses in the nozzle and pulse jets.
Finally, the Response Surface Method (RSM) was conducted to determine suitable conditions for the IDM injector injecting the jet into the polyacrylamide gels. The optimal conditions were a travelling distance of 5.26 mm, fluid volume of 0.18 mL, and pressure reservoir of 11.90 bar. These provided the maximum dispersion area in the polyacrylamide gels. However, the accuracy and reliability of the jet need to be further investigated and improved before application by the IDM injector to animal and/or human skins.
|
