Comparative bioavailability of two hydrofluoroalkane formulations of formoterol fumarate both delivered by pressurised metered dose inhaler.

A randomised, open-label, single dose, four-period crossover study was performed in healthy male human subjects to compare the pharmacokinetics of formoterol fumarate (CAS 43229-80-7) after inhalation from two different hydrofluoroalkane (HFA) pressurised metered dose inhaler (pMDI) formulations at two dose levels, 12 and 24 microg. This is the first study which has evaluated two HFA formulations of formoterol. Fourteen subjects were randomised, of which 13 completed the study.