Geng Michael Tian
An Initial Analysis of Enhanced Condensational Growth for Respiratory Drug Delivery

The feasibility of improving respiratory drug delivery using enhanced condensational growth (ECG) has previously been demonstrated using both in vitro and computational fluid dynamics (CFD) models of the upper respiratory airways. However, condensational growth and deposition in the tracheobronchial (TB) region beyond approximately generation G4 was not considered. It is currently not clear how far into the lungs condensational growth will continue. It is also conceivable that some evaporation may occur in the deep lung once subsaturated conditions are reached for non-hygroscopic aerosols. The objective of this study is to evaluate the ECG delivery of respiratory submicrometer pharmaceutical aerosols in a single path model extending from the mouth-throat (MT) to the end of the TB region. This single path model is constructed by continuing only one branch of each bifurcation through generation G16. Separate streams of nebulized submicrometer aerosol and saturated humidified air were combined as they were introduced into a realistic MT-TB single path geometry. Aerosol growth was observed in the upper respiratory tract and continued in the lower TB region under ECG conditions. These results illustrate that the ECG approach can potentially be utilized for targeted respiratory drug delivery with high efficiency to the respiratory airways and minimal extrathoracic deposition.

Back to Seminar Page