Group 1 will assess pharmacokinetics, Group 2 will assess pharmacodynamics. PK interim analysis to determine requirement for PK extension.
Group 1 (PK) blood sampling and safety assessments up to 36 hours post-dose for 3 study periods. Results from PK stage will determine if Group 2 (PD) is required. Group 2 (PD) will assess LABA only effects (as confirmed in interim analysis).
Group 2 (PD) to include 2 overnight stays for 5 study periods. Volunteers will receive a single dose of study medication, with discharge on Day 2.
Study treatments are fluticasone/formoterol BAI, fluticasone/formoterol pMDI with/without spacer, formoterol alone without spacer, and low dose fluticasone/formoterol without spacer.
Volunteers will undergo blood sampling, and safety assessments up to the morning of discharge. An inspiratory flow recorder (IPR) will be used for training and to monitor inspiratory flow rate, inhaled volume and inhalation technique.
