 This 4-week clinical study evaluates the efficacy and safety of Albuterol Sulfate HFA Inhalation Aerosol in comparison with the Active Control, Proventil-HFA 3M Pharmaceuticals, Inc in pediatric patients 4-11 years old with mild-to-moderate asthma. In addition, pharmacokinetic profile in this population will be evaluated using a population PK approach with sparse blood samples. 