This is a Phase IIb, randomized, double blind, chronic dosing (28 days), four period, five treatment, incomplete block, crossover design in subjects with moderate to severe COPD. The overall objective is to demonstrate that the combination of budesonide (BD; PT008) and formoterol fumarate (FF; PT005) in a metered-dose inhaler (MDI); (BFF MDI; PT009) provides benefit on lung function compared with BD MDI in subjects with moderate to severe COPD.

Inclusion Criteria:

• Informed Consent Form (ICF) prior to any study related procedures
• COPD Diagnosis: Subjects with an established clinical history of COPD as defined by the American Thoracic Society (ATS)/European Respiratory Society (ERS)
• Tobacco Use: Current or former smokers with a history of at least 10 pack years of cigarette smoking
• Women of non-childbearing potential or medically acceptable contraception for women of child-bearing potential and males with female partners of childbearing potential
• Severity of Disease: Subjects with an established clinical history of COPD and severity defined as: FEV1/forced vital capacity (FVC) ratio of <0.70; At Screening (Visit 1a/b), post bronchodilator FEV1 must be <80% predicted normal value, calculated using NHANES III (Third National Health and Nutrition Examination Survey) reference equations; the measured FEV1 must also be ≥30% of predicted normal value; at Visit 2, the average of the 60 minutes and 30 minutes pre dose FEV1 assessments must be <80% predicted normal value calculated using NHANES III reference equations
• Screening clinical laboratory tests must be acceptable to the Investigator
• Screening ECG must be acceptable to the Investigator
• Chest x ray or computerized tomography (CT) scan within 6 months prior to Visit 1a must be acceptable to the Investigator.

Exclusion Criteria:

• Significant diseases other than COPD, ie., disease or condition which, in the opinion of the Investigator, may put the subject at risk because of participation in the study or may influence either the results of the study or the subject's ability to participate in the study
• Pregnancy, nursing female subjects, or subjects trying to conceive, or not using medically acceptable form of contraception
• Asthma: Subjects who have a primary diagnosis of asthma (Note: Subjects with a prior history of asthma are eligible if COPD is currently their primary diagnosis).
• Alpha 1 Antitrypsin Deficiency: Subjects who have alpha 1 antitrypsin deficiency as the cause of COPD -Active pulmonary disease such as active tuberculosis, lung cancer, bronchiectasis, sarcoidosis, lung fibrosis, primary pulmonary hypertension, interstitial lung disease, and uncontrolled sleep apnea (ie., in the opinion of the Investigator severity of the disorder would impact the conduct of the study)-
• Clinically significant neurologic, cardiovascular, hepatic, renal, endocrinologic, pulmonary, hematological, psychiatric, or other medical illness that would interfere with participation in this study
• Poorly Controlled COPD
• History of ECG abnormalities
• Cancer not in complete remission for at least 5 years
• Clinically significant, symptomatic prostatic hypertrophy
• Male subjects with a trans-urethral resection of the prostate or full resection of the prostate within 6 months prior to Screening
• Clinically significant bladder neck obstruction or urinary retention
• Inadequately treated glaucoma
• History of an allergic reaction or hypersensitivity to any drug or to any component of the formulations used in this study

Double Blind