The primary objectives of the study are: Part 1: to characterize the potency and variability of dose response on efficacy (Provocative concentration of methacholine causing at least a 20% fall in forced expiratory volume (FEV1) \[PC20\]) of salbutamol administered via MDI with salbutamol HFA-134a or salbutamol HFA-152a in participants with mild asthma. Part 2: to compare the comparative dose response on efficacy (PC20) of salbutamol when administered via MDI with salbutamol HFA-134a or salbutamol HFA-152a in participants with mild asthma.
Male or female; females may be of childbearing potential, of nonchildbearing potential, or postmenopausal.
Participant must be 18 to 65 years of age inclusive, at the time of screening.
≥50 kg, at the time of screening.
Body mass index (BMI) with 19.0-35.0 kg/m2 inclusive, at the time of screening.
Medical Conditions
A history of life-threatening asthma or asthma that is unstable in the opinion of the investigator.
A history of respiratory diseases to include (but not limited to): pneumothorax, pulmonary fibrotic disease, bronchopulmonary dysplasia, chronic bronchitis, cystic fibrosis, bronchiectasis, interstitial lung disease, emphysema, chronic obstructive pulmonary disease, tuberculosis, or other respiratory abnormalities other than asthma.
Asymptomatic gallstones.