CFD analysis of the aerosolization of carrier-based dry powder inhaler formulations

This study applied computational fluid dynamics (CFD) analysis to investigate the role of device design on the aerosolization of a carrier-based dry powder inhaler (DPI). The inhaler device was modified by reducing the inlet size, decreasing the mouthpiece length and increasing the mesh grid voidage. The flow patterns in the inhaler device were examined. It was observed that there was no significant influence on the aerosol performance with the reduced mouthpiece. When the inlet size was reduced to one third of the original one, the fine particle fraction (FPF), defined as mount of inhalable fine particles below 5μm in the aerosol, was improved significantly from 17.7% to 24.3%. The CFD analysis indicated that the increase in FPF was due to increasing air velocity for the smaller inlet. No significant difference was shown in FPF when the grid voidage was increased, but more drugs deposited in the mouthpiece and throat. © 2013 AIP Publishing LLC.