Albuterol DPI (A006) Clinical Study-B3:Efficacy, Dose-ranging and Safety Evaluation

This study evaluates the efficacy, dose-ranging and safety profiles of A006, an Albuterol dry powder inhaler (DPI), in the dose range of 110 to 220 mcg per dose in comparison to a DPI Placebo Control and an Albuterol metered dose inhaler (MDI) Active Control.

This study is designed to evaluate the efficacy and safety profiles of A006 and to assist in identifying the optimum dose of A006 for future clinical studies. Proventil® HFA MDI, a currently marketed Albuterol MDI product, will be used as an Active Control. The study also employs a Placebo Control DPI, which has the same configuration as the A006 DPI except that it contains no active ingredient.

Eligibility Criteria:
Inclusion Criteria:

* Generally healthy, male and female adults, 18-55 years of age at Screening
* With mild-to-moderate persistent asthma for at least 6 months prior to Screening, and having used inhaled β-agonist(s) for asthma control
* Demonstrating a Screening Baseline FEV1 at 50.0 - 85.0% of predicted normal
* Demonstrating a ≥ 15.0% Airway Reversibility in FEV1 within 30 min after inhaling 2 actuations of Proventil® MDI (180 mcg) at Screening
* Demonstrating Peak Inspiratory Flow Rate (PIF) within 80-150 L/min (after training), for at least 2 times consecutively with a maximum of 5 attempts
* Demonstrating proficiency in the use of a DPI and an MDI after training
* Females of child-bearing potential must be non-pregnant, non-lactating; both males and females enrolled into the study must agree to practice a clinically acceptable form of birth control (including but not limited to, abstinence, double barrier, etc)
* Having properly consented to participate in the trial

Exclusion Criteria:

* A smoking history of ≥ 5 pack-years, or having smoked within 6 months prior to Screening
* Upper respiratory tract infections or lower respiratory tract infection within 6 weeks, prior to Screening
* Asthma exacerbations that required emergency care or hospitalized treatment, within 4 weeks prior to Screening
* Any current or recent respiratory conditions that, per investigator discretion, might significantly affect pharmacodynamic response to the study drugs, including cystic fibrosis, bronchiectasis, tuberculosis, emphysema, and other significant respiratory diseases besides asthma
* Concurrent clinically significant cardiovascular (e.g. hypertension and tachyarrhythmia and bradyarrhythmia), hematological, renal, neurologic, hepatic, endocrine, psychiatric, malignant, or other illnesses that in the opinion of the investigator could impact on the conduct, safety and evaluation of the study
* Known intolerance or hypersensitivity to any of the ingredients of the study drug DPI or Proventil® HFA MDI (i.e., Albuterol, sulfate, lactose, milk protein, HFA-134a, oleic acid, and ethanol)
* Baseline ECG at Screening or Visit 1 showing any single or multiple premature ventricular contractions (PVC)
* Baseline ECG at Screening or Visit 1 with a confirmed (through performing a second ECG) QTc reading greater than 450ms
* Use of prohibited drugs or failure to observe the drug washout restrictions
* Having been on other clinical drug/device studies in the last 30 days prior to Screening.