Needle-free, dermal delivery of dry powdered drugs using contoured shock tubes

Abstract

A unique form of needle-free drug delivery system has been developed at Oxford University and PowderJect Pharmaceuticals pic. The principle behind the concept is to accelerate drug particles, using a gas flow, so that they attain sufficient velocities to enter the skin and achieve a therapeutic effect. This paper presents a system of delivery, called the Contoured Shock Tube (CST), configured to deliver particles to the skin with a narrow and controlled velocity distribution and a uniform spatial distribution. The rationale for the CST concept and design is discussed. The primary gas flow regimes of a prototype CST are identified through Pitot-static pressure surveys. The action of the gas flowfield in imparting momentum to the drug particles is investigated through Particle Image Velocimetry (PIV). The results are compared with ideal, inviscid calculations. Finally, the CST is evaluated as a means of powdered drug delivery with a brief discussion of the operating conditions. Show more