Lung Deposition of Extrafine Versus Nonextrafine Aerosols at Low Inhalation Flow Rates in Adult Asthma Patients: A Composition Study

Backgroud: A key attribute in selecting an oral inhaler device for chronic obstructive pulmonary disease (COPD) and asthma is its ability to dispense a high degree of pulmonary deposition of the drug at low inspiratory flows. Methods: In this study, the lung deposition of extrafine formulations of beclomethasone dipropionate (BDP) and formoterol fumarate (FF) (pressurized metered-dose inhaler [pMDI] and dry powder inhaler [DPI], NEXThaler) was compared with that of nonextrafine formulations of fluticasone/salmeterol (FP/SAL) Diskus DPI and budesonide/formoterol (BUD/FF) Turbuhaler DPI in 10 patients. Diskus intrathoracic (peripheral and central) lung deposition was estimated at low inhalation flow rates (30 and 40 L/min) via validated functional respiratory imaging (FRI) and computational fluid dynamics (CFD) methods. Results: The BDP/FF NEXThaler and BDP/FF pMDI had the highest median percentages of intrathoracic deposition, with consistent mean values of approximately 50% and 40%, respectively. The median percentage of peripheral deposition from extrafine inhalers was above 30% with BDP/FF NEXThaler and pMDI, 5% or less with the FP/SAL Diskus at both flow rates, and ranged between 12% and 22% with the BUD/FF Turbuhaler DPI at flow rates of 30 and 40 L/min, respectively. Conclusions: Extrafine BDP/FF using NEXThaler and pMDI resulted in greater peripheral deposition of both the inhaled corticosteroid and long-acting beta-agonists moieties than the nonextrafine FP/SAL Discus and BUD/FF DPIs did.