Experimental investigation of aerosol deposition through a realistic respiratory airway replica: An evaluation for MDI and DPI performance

Purpose: In the present work, a comparison between MDI and DPI for evaluating performance of the devices were carried out by experimentally investigating the deposition parameters through a realistic airway replica. Methods: Computed tomography (CT) images of the respiratory airway of a healthy subject were used to develop the realistic model. The airway replica was included extrathoracic, trachea, and tracheobronchial tree up to fourth generations which was fabricated by rapid prototyping. Afterward, in vitro experiments were performed to validate the airway model by comparing the total deposition (G0 to G3) of present replica with available data in the literature. Drug deposition (Salbutamol) in the model was measured by determining concentration of the segments sample by High Performance Liquid Chromatography (HPLC) assay. Results: Deposition parameters were used for investigating the deposition patterns of the inhaled particles. Results showed that inertial impaction is the dominant mechanism in the most regions of the replica. It was found that the MDI delivered more drug to the tracheobronchial tree compared to the DPI for three different flow rate. Conclusion: The developed realistic respiratory airways model provided an opportunity to more accurately evaluate the performance of drug delivery devices and studying mechanisms of the drug deposition.