Nasal Airway; Ultrafine, Fibre; Morphology; CFD; Deposition

A human nasal cavity was reconstructed from CT scans to make a Computational Fluid Dynamics (CFD) model. With this model, fluid flow and inhalation of aerosol analysis can be investigated. The surface of the interior nasal cavity is lined with highly vascularised mucosa which provides a means for direct drug delivery into the blood stream. Typical sprayed particles from a nasal spray device produce a particle size distribution with a mean diameter of 50μm, which leads to early deposition due to inertial impaction. In this study low-density drug particles and submicron particles (including nanoparticles) are used to evaluate their deposition patterns. It was found that the low-density particles lightens the particle inertial properties however the particle inertia is more sensitive to the particle size rather than the density. Moreover the deposition pattern for nano- particles is spread out through the airway. Thus an opportunity may exist to develop low-density and nanoparticles to improve the efficiency of drug delivery to target deposition on the highly vascularised mucosal walls.