Pharmacodynamic Bioequivalence of Metered Dose Inhalers of Albuterol Sulfate in Patients With Stable Mild Asthma

Inclusion Criteria: * Male and non-pregnant female subjects (18-65 years of age) * Stable mild asthmatics based on National Asthma Education and Prevention Program (NAEPP) guidelines. * Forced Expiratory Volume in 1 second ( FEV1) ≥ 80% of predicted. Airway responsiveness to methacholine demonstrated by a pre-albuterol dose (baseline) PC20 ≤ 8 mg/ml. * Nonsmokers for at least 1 year prior to the study and a maximum smoking history of five pack-years (the equivalent of one pack per day for five years). * Written informed consent. Exclusion Criteria: * Conditions which could alter airway reactivity to methacholine (e.g., pneumonia, upper respiratory tract infection, lower respiratory tract, viral bronchitis and/or sinobronchitis) within six weeks preceding the screening visit. * History of seasonal asthma exacerbations, in which case the patient should be studied outside of the relevant allergen season. * History of cystic fibrosis, bronchiectasis or other respiratory diseases. * History of cardiovascular, renal, neurologic, liver or endocrine dysfunction, or chronic condition that could put the safety of the patient at risk during the study or affect the efficacy and safety analyses during the study. * Treatment in an emergency room, urgent care center, or hospitalization for acute asthmatic symptoms within the past 6 months or need for daily oral corticosteroids within past 3 months. * Known intolerance or hypersensitivity to any component of the albuterol metered dose inhaler (MDI).