Enhancing aerosol delivery in asthma and COPD: a comparison of MDI, valved holding chamber, and DPI systems using functional respiratory imaging (FRI).

Effective respiratory therapy relies heavily on inhaler device efficiency and patient technique. While device performance is well-documented in idealized induction ports, there remains a critical lack of data integrating patient-specific disease states to compare pressurized metered-dose inhaler (MDI) and valved holding chamber (VHC) efficiency against legacy dry powder inhaler (DPI) formulations. This study addresses this gap using Functional Respiratory Imaging (FRI) which combines high-resolution computed tomography (CT) scans with Computational Fluid Dynamics (CFD) to quantitatively assess aerosol deposition in asthma and Chronic Obstructive Pulmonary Disease (COPD) patient models. We evaluated the performance of MDIs alone and with various VHCs, against DPIs under optimal and sub-optimal inhalation profiles. Our results indicate that while MDIs alone require precise coordination, the addition of a VHC (AeroChamber Plus Flow-Vu) maintains high intrathoracic deposition and significantly minimizes oropharyngeal deposition, even with inhalation delays. Furthermore, the MDI/VHC combination demonstrated superior lung delivery compared to other tested VHCs and DPIs. Notably, the MDI/VHC system exhibited greater consistency across varying flow rates, whereas the DPIs tested showed higher sensitivity to sub-optimal maneuvers. Using FRI as tool for comparative inhaler assessment these results suggest that MDIs with appropriate VHCs provide the most consistent medication delivery for obstructive airway diseases.