A Study of the Efficacy and Safety of EP-101 ( (SUN101) in Subjects With Moderate to Severe Chronic Obstructive Pulmonary Disease

Inclusion Criteria: * Male and female subjects age 35 through 75 years, inclusive. * A clinical diagnosis of moderate to severe COPD according to GOLD guidelines (2011). * Current smokers or ex-smokers with at least 10 pack-year smoking history (eg, at least 1 pack/day for 10 years, or equivalent). * Post-bronchodilator (following inhalation of ipratropium bromide MDI) FEV1 ≥ 30% and ≤ 70% of predicted normal value during the Screening Period. * Post-bronchodilator (following inhalation of ipratropium bromide MDI) FEV1/FVC ratio \< 0.70 during the Screening Period. * Post-bronchodilator (following inhalation of ipratropium bromide MDI) improvement in FEV1 ≥ 12% and ≥ 100 mL during the Screening Period. * Ability to perform reproducible spirometry according to the American Thoracic Society (ATS) and European Respiratory Society (ERS) guidelines (2005). * Subject, if female ≤ 65 years of age and of child bearing potential, must have a negative serum pregnancy test at screening. Females of childbearing potential must be instructed to and agree to avoid pregnancy during the study and must use an acceptable method of birth control: * a. An oral contraceptive, an intrauterine device (IUD), implantable contraceptive, transdermal or injectable contraceptive for at least 1 month prior to entering the study with continued use throughout the study and for thirty days following study participation. * b. Barrier method of contraception, eg, condom and/or diaphragm with spermicide while participating in the study. * c. Abstinence. * Willing and able to provide written informed consent. Exclusion Criteria: * Current evidence or recent history of any clinically significant and unstable disease (other than COPD) or abnormality in the opinion of the Investigator that would put the subject at risk or which would compromise the quality of the study data; including but not limited to cardiovascular disease, myocardial infarction, cardiac failure, uncontrolled hypertension, life-threatening arrhythmias, uncontrolled diabetes, neurologic or neuromuscular disease, liver disease, gastrointestinal disease or electrolyte abnormalities. * Current evidence or history of clinically significant abnormal cardiac rhythm and/or conduction findings, including Holter monitoring results during the Screening Period. * Concomitant pulmonary disease or primary diagnosis of asthma. * History of malignancy of any organ system, treated or untreated within the past 5 years, with the exception of localized basal cell carcinoma of the skin * Recent history of COPD exacerbation requiring hospitalization or need for increased treatments for COPD within 6 weeks prior to the Screening Period. * Use of daily oxygen therapy \> 10 hours per day. * Use of systemic steroids within 3 months prior to the Screening Period. * Respiratory tract infection within 6 weeks prior to or during the Screening Period. * History of tuberculosis, bronchiectasis or other non-specific pulmonary disease. * History of urinary retention or bladder neck obstruction type symptoms. * History of narrow-angle glaucoma. * Prolonged QTc interval (\> 450msec for males and \> 470msec for females) during the Screening Period, or history of long QT syndrome. * Recent history (previous 12 months) of excessive use or abuse of narcotic/illegal drugs. * History of hypersensitivity or intolerance to β2-agonists or anticholinergics. * Participation in another investigational drug study where drug was received within 30 days prior to the Screening Period. * Female subject who is pregnant or lactating