Abstract

In this work, the aim is to develop a practical method of controlled release for drug delivery using the concept of needle-free injection as a replacement for traditional hypodermic needles. The basic idea behind the needle-free injection technology is to generate a high-speed liquid jet to effectively deliver medication to the different layers of skin. The power source and the release mechanism remain the key factors influencing the exit velocity and jet diameter for such technology, which in turn are critical in determining how deep the injection will penetrate the skin and how much medication can be effectively delivered. The idea for this work is to implement a pressure gain combustion process as the power source into the needle-free injection system design. Two types of combustion-driven injector devices are proposed and developed, namely a system driven by detonative combustion for high power injection applications and a small-scale, handheld device powered by a deflagration combustion mode. Experiments and modeling are proposed to understand the basic relationship between different injection parameters using the proposed mechanism of controlled release in order to design more efficient injectors and resolve many of the current shortcomings of needle-free injection technology. The proposed injectors are assessed by measurement of the output jet's stagnation pressure and the associated penetration depth.