Lung deposition of aclidinium bromide from Genuair, a multidose dry powder inhaler.

Background: Aclidinium bromide is a novel, long-acting inhaled muscarinic antagonist currently in development for the treatment of chronic obstructive pulmonary disease (COPD). A next-generation multidose dry powder inhaler will be used for the delivery of aclidinium bromide.

Objectives: To quantify whole lung deposition and regional lung deposition of aclidinium delivered by a multidose dry powder inhaler (Genuair) in healthy subjects.

Methods: A single dose (200 microg) of aclidinium bromide, radiolabelled with (99m)Tc, was administered from the multidose dry powder inhaler at a targeted peak inspiratory flow rate (PIFR) of 90 litres/min in 12 healthy males (18-63 years). Gamma scintigraphy was used to quantify drug deposition in the lungs and oropharynx, as well as amounts retained in the inhaler and exhaled. The quantities of drug deposited in 6 concentric regions within the lungs were also determined.

Results: The mean (+/- SD) PIFR was 79.0 +/- 9.4 litres/min. The mean (+/- SD) percentages of the metered dose deposited in the whole lung and oropharynx were 30.1 +/- 7.3 and 54.7 +/- 7.2%, respectively. Deposition of aclidinium occurred in all 6 lung zones, but was highest in the most central zone.

Conclusions: These results demonstrated that the multidose dry powder inhaler delivered aclidinium efficiently to the lungs. The whole lung deposition seen in this study is an indication of the likely whole lung deposition in COPD patients who inhale with similar PIFRs; however, further studies in patients are required to confirm this.