Computational multiphase flow analysis for improving targeted nasal drug delivery

Nasal drug delivery is a popular way to treat several respiratory diseases, which are a common source of morbidity. It has proved to achieve better, systematic bioavailability than oral delivery. However, its efficacy is compromised by current devices that do not perform to the fullest. For the potential of these treatment technologies to be realised, new device designs are needed that preferentially target drug delivery to specific parts of the nose. The delivery method preference is based on treatment requirements and patients comfort. In this research, three different alternative drug delivery methods, namely nasal spray, nasal saline irrigation and nebulizers, are screened using computational methods. High-fidelity numerical simulations were performed to characterize the liquid sheet formation and its disintegration into droplets of a nasal spray. The study aimed to provide insight into the internal and external near-nozzle spray characterization of a continuous spray and to establish good validation against experimental data. Design exploration of irrigation devices and evaluation of head-tilt positions were carried out to get an insight into flow dynamics during nasal irrigation. The results provided comprehensive information on regional penetration, adding value to squeeze bottle/device design and guidance for clinicians and patients for effective targeted nasal drug delivery. In addition, CFD investigations of the influence of nebulizer administration techniques, such as breathing patterns and nozzle types, were carried out. The outcomes of this work will assist with the development of new innovative nasal drug delivery device designs for effective respiratory treatment based on numerical analyses.