Multiphase Flows in Pharmaceutical Applications

Dry powder inhalers (DPI) have been widely used for drug delivery to the respiratory tract to treat disease such as asthma and cystic fibrosis. It is therefore important to improve their efficiency through better understanding of dispersion mechanisms of powders in devices. In this aspect, numerical modeling has been playing an increasingly important role. This chapter reviews the recent progress using computational fluid dynamics (CFD) and the discrete element method (DEM) to investigate the airflow and de-agglomeration in DPIs. In particular, with the coupled CFD and DEM approach, the models are able to generate detailed information at the particle scale, leading to improved and novel designs of next generations of DPI systems.