This study will be a randomized, double-blind, repeat dose, two period crossover study, with FF as the control. During each of two treatment periods subjects will receive either FF/VI 100/25 micrograms (mcg) or FF 100 mcg daily on 14 consecutive mornings via the novel dry powder inhaler. Approximately 26 subjects will be recruited into this study, with a target of 20 completed subjects. Safety, tolerability, pharmacokinetics and glucose , potassium and cortisol levels will be investigated.