 At clinical Visit 3, a sufficient number of patients will be subject to a population pharmacokinetic PPK study to obtain a minimum of 6 subjects per arm with complete and correct 4 PK samples. An indwelling IV catheter may be used, as an alternative to repeated venipunctures, for PPK samples. An appropriate anticoagulant may be used to maintain the catheter patency. Four blood samples 5.0 mL each will be taken from a hand or forearm vein of the subject, at pre-scheduled 4 time points: 2, 4, 6 and 8 hr post-dose each with a 15 min window. No inhalation of the study drug or rescue medication should take place until completion of the 8-hr PK sampling, unless needed for rescue, at which point the subject will not be considered evaluable for the PK endpoint. 