This clinical trial is a Phase I, single-centre, multiple-dose, randomised, open-label, controlled, 2-way cross-over study to assess the effect on MCC of the new HFA 152a propellant (5 inhalations BID for 8 days) versus the marketed HFA 134a propellant (5 inhalations BID for 8 days) in adult healthy volunteers by measuring the clearance from the lungs of inhaled radioaerosol.~A total of 20 subjects will be randomised in the study.~Standard safety assessments will be conducted during the Study, including safety blood and urine laboratory tests, vital signs, physical examinations, ECGs, spirometries and observations of any adverse events.
The primary objective of this study is to assess the effect of multiple doses of the HFA-152a propellant and the HFA-134a propellant on mucociliary clearance (MCC).