Dry powder inhalers for the treatment of asthma: an engineer's approach

Dry powder inhalers (DPI) are an increasingly popular method of treatment for the symptoms of asthma and chronic pulmonary disease (COPD). However, due to the nature of DPIs' complicated drug delivery system, research into development and improvement provides a significant challenge. While there are many different devices available on the market, none of these provide consistent delivery for varying inhalation profiles. This variability is determined by the drug formulation, the deign of the device and the patient's inhalation profile. This paper focuses on the proof of concept and early results of research into a systematic study of the influence of the physicochemical properties of the carrier particles, and the nature of the fluid flow, on powder fragmentation and transport. this thesis paper will be particularly useful for the researchers furthering this study and the industry partner DFE Pharma. The research was conducted through a controlled flow that was fed into a unique rig, with measurements taken from a laser photodiode setup. The results found that the majority of data that is achieved is located around the far end of the pocket with respect to the flow and and follows known correlations between size and evacuation times.