Lung Deposition of Formoterol HFA (Atimos ® /Forair ® ) in Healthy Volunteers,Asthmatic and COPD Patients

In this study, the influence of lung function on lung deposition of a radioactively labeled Formotoerol HFA MDI (Forair^®) was investigated. Eighteen subjects were measured: 6 healthy subjects (FEV₁ = 107% pred), 6 patients with Asthma (FEV₁ = 72% pred), and 6 patients with COPD (FEV₁ = 40% pred). The lung deposition of the radioactive-labeled drug was measured with a gamma camera. The lung deposition relative to the emitted dose was 31% for healthy subjects, 34% for asthmatics, and 35% for COPD patients. These data suggest a comparable lung deposition in the different populations. There was no significant correlation between lung function (FEV₁) and lung deposition. The extrathoracic deposition was around 50%. The finding were that lung deposition of the inhaled Formoterol did not depend on lung function and the relative high values of lung deposition can be explained by the small particle size (0.8 μm) of the HFA–Formoterol–Formulation and the slow inhalation (30 L/min flow) used in this study. It can be concluded, that with this modern HFA drug formulation, the deposition is high, even in obstructed lungs.