Mouth-throat deposition with non-ballistic pharmaceutical aerosol inhalation devices

In this thesis, the enhancement of aerosol deposition in the mouth-throat region by non-ballistic pharmaceutical aerosol devices is investigated and a model to predict the extrathoracic deposition is developed.; Aerosol deposition was found to be a function of the particle Stokes number based on the inlet diameter and the predicted velocity near the impaction location. Although increased inlet turbulence intensity was found to increase deposition, it was found to be a secondary effect after the Stokes number effect.; In order to investigate the flow field in the oral cavity caused by the confined turbulent jets, a commercial computational fluid dynamics (CFD) package combined with an in-house particle tracking code was employed to predict the flow fields and aerosol deposition within the region. The CFD simulation predicted fluid jet structures in the oral cavity for all inlets less than 17mm in diameter with elevated deposition near the point of jet impingement on the upper, rear wall of the oral cavity.; A model was developed to predict the aerosol deposition in the oral cavity based on the straight tube and contraction nozzle tests. The model was found to give much closer estimates of oral cavity deposition than previous extrathoracic deposition models available in the literature. A small systematic underprediction of the oral cavity deposition for entry through dry powder inhaler geometries was observed.; Finally, a simple model was developed for predicting dry powder inhaler aerosol deposition by extrapolating the oral cavity model to polydisperse aerosols and combining it with the model of Stahlhofen et al. for pharynx, larynx and trachea deposition. Results were validated against published in vivo studies with a number of dry powder inhalers. The model was found to improve predictions of the total extrathoracic deposition and to significantly shift the deposition location within the extrathoracic region from the larynx to the oral cavity as is observed in vivo. (Abstract shortened by UMI.)...