Plume Characteristics of Two HFA-Driven Inhaled Corticosteroid/Long-Acting Beta2-Agonist Combination Pressurized Metered-Dose Inhalers.

Introduction: New inhalers propelled by hydrofluoroalkanes (HFAs) have improved plume characteristics: higher fine particle fraction, and warmer plumes with reduced force and velocity. Together, this may avoid reflex interruption of inhalation and improve lung deposition of the inhaled drugs. However, even with HFA-propelled pressurized metered-dose inhalers (pMDIs), there are notable differences in device properties.