GSK615915A is being developed as a novel surfactant for use in the formulation of GSK's future generation of Metered Dose Inhalers (MDIs). A surfactant in a MDI would provide a more stable drug suspension, this in turn will produce a consistent dose of drug being delivered with each puff.

Inclusion Criteria:

• Women of non-child bearing potential.
• Body weight = 50 kg (110 lbs) for men and = 45 kg for women and Body Mass Index (BMI) within the range 19.0-30.0 kg/m²
• The subject is a current non-smoker who has not used any tobacco products in the last 12 months with a pack history of = 10 pack years.
• The subject has demonstrated the ability to correctly use a metered dose inhaler device.
• If asthmatic:

The subject must be clinically stable The subject has a baseline FEV1 = 80% of predicted.

Exclusion Criteria:

• As a result of the medical interview, physical examination or screening investigations, the Physician Responsible considers the volunteer unfit for the study.
• The subject has a history of allergy to excipients, MDI propellants, or a history of drug or other allergy that, in the opinion of the physician responsible makes the volunteer unfit to participate.
• The subject has recently participated in another clinical trial.
• The subject has used prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John’s Wort) within 7 or 14 days.
• The subject has an average weekly alcohol intake of greater than 21 units if male or 14 units if female, or an average daily intake of greater than 3 units regularly, where 1 unit is equivalent to a half-pint (220mL) of beer or 1 (25ml) measure of spirits or 1 glass (125ml) of wine.
• Any history of breathing problems (e.g. history of asthmatic symptoms).
• The subject is infected with the hepatitis B, hepatitis C, or HIV virus.
• The subject is has a positive drugs of abuse test.
• The subject has had a respiratory tract infection within 4 weeks of the start of the study.
• The subject has a past or present disease, which as judged by the Doctor, may affect the outcome of this study.
• The subject has a history of life-threatening asthma.
• The subject has taken inhaled, nasal or dermal steroids within 4 weeks or oral steroids within 8 weeks of the start of the study.
• The subject has taken long acting inhaled beta 2 agonists within 96 hours before the screening visit.
• The subject has taken short acting inhaled beta 2 agonists within 8 hours before the screening visit.
• The subject is unable to abstain from other drugs that may interfere with the conduct of the study or its interpretation.
• The subject has ongoing rhinitis that requires treatment.