A 2-group healthy volunteer study to compare a breath actuated inhaler (BAI) and a pressurised metered dose inhaler (pMDI) with and without spacer.

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.

Inclusion Criteria:

• Male or female subjects aged 18 years or over.
• Healthy and free of significant abnormal findings as determined by medical history, physical examination, vital signs, laboratory tests and ECG.
• Normal lung function (FEV1 >90% of predicted normal value).
• Demonstrate satisfactory technique in the use of the study drug devices.
• No use of steroid medication (systemic or topical) within 8 weeks prior to study screening.

Exclusion Criteria:

• Subjects who use any asthma medication or are knowingly regularly exposed to asthma medication.
• Any history of drug or alcohol abuse.
• Any history of conditions that might interfere with drug absorption, distribution, metabolism or excretion.
• History of asthma, COPD, or other bronchial or lung diseases.
• User of steroid medication (systemic or topical) within 8 weeks prior to study screening.