The effect of the design of the mini cyclonic DPIs on the emitted dose by modelling approach

Although dry powder inhalers (DPIs) provide distinct advantages for delivering aerosols to patients, there are still barriers that need to be passed through such as low in vivo efficiency, drug agglomeration, and inconsistency of delivered dose at different flow rates. Cyclones have widely been used in many fields, including powder inhalation drug delivery. With a good design based on mechanistic understanding, small portable cyclones may have the potential to overcome some of the above-mentioned shortcomings. However, the investigation of the miniature cyclone to optimize DPIs for inhalation drug delivery is still limited. Ten miniature cyclones are designed for studying the effects of different geometric parameters, various flow rates, and particle sizes on device-emptying by modelling approach. The simulation results indicated that different cyclones have different distributions of fluid fields. The emitted fraction (EF) is highly sensitive to cyclone geometries and particle size. For most models, the impact of the flow rate on EF is not obvious, and it can be ignored if the inhalation rate exceeds 45L/min. The particle size distribution can be controlled by adjusting the cyclone parameters. This paper provides a comprehensive insight into the influence of geometric parameters, particle sizes, and flow rates on the EF of miniature cyclones. The results should be helpful for designing new devices based on the different delivery requirements, which is beneficial for the future improvement of inhaler devices.