 This will be a randomized, double-blind, single-dose, three-period balanced crossover study in adult healthy subjects. Each of the 18 subjects will be randomized to receive a treatment sequence consisting of each of the three treatments FF 400 microgram mcg, UMEC 500 mcg and FF 400 mcgUMEC 500 mcg, in three consecutive periods, with a wash-out period of 7 to 10 days between the periods. 