The purpose of this study is to demonstrate the pharmacodynamic bioequivalence of the test product to the reference product as measured by increases in FEV1.

A single center, open label, single dose study to demonstrate the pharmacodynamic bioequivalence of the test and reference metered dose inhalers containing albuterol sulfate or albuterol sulfate/ipratropium in adult patients with COPD.

Inclusion Criteria:

• Provide written informed consent
• Diagnosis of COPD as defined by the American Thoracic Society/European Respiratory Society guidelines characterized by progressive airflow limitation associated with abnormal inflammatory response of the lungs to noxious particles or gases primarily caused by cigarette smoking.
• Have an established COPD clinical history, symptomatic with dyspnea, chronic cough, chronic sputum production or wheezing. At Visit 1, FEV1/FVC ratio must be less than 0.70 or at least 10% less than the FEV1/FVC ratio determined by the predicted normal value. FEV1 must be less than 70% of the predicted normal value and greater than 25% of the predicted normal value.
• Must be using one or more inhaled bronchodilators for treatment of COPD at the time of Visit 1.
• Current or former smokers, with a history of at least 10 pack-years of cigarette smoking. Number of pack-years = (number of cigarettes per day/20) X (number of years smoked).
• Willing, and in the opinion of the investigator, able to adjust current COPD therapy as required by the protocol.

Exclusion Criteria:

• Current diagnosis of other respiratory disorder(s) including, but not limited to: alpha-1-antitrypsin deficiency; lung cancer; cystic fibrosis; tuberculosis; sarcoidosis; idiopathic pulmonary fibrosis; primary pulmonary hypertension; or pulmonary thromboembolic disease. Patients with concomitant COPD and asthma will be allowed to participate.
• Diagnosis of non-respiratory disorder(s) that are currently affecting lung function, as determined by he principal investigator including, but not limited to: congestive heart failure; symptomatic cardiac arrhythmia; symptomatic seizure disorder; dementia; lupus; rheumatoid arthritis; or liver cirrhosis.
• Unable to abstain from protocol defined prohibited medications during the screening and testing period.
• Unable to withhold short acting bronchodilators for 6 hours prior to spirometry testing at the study visit.
• Unable to perform acceptable or repeatable spirometry or comply with other study procedures.
• Known allergic reaction to albuterol sulfate or ipratropium bromide.
• Diagnosis of cancer that is not presumed to be in remission or cured.
• Active alcohol or drug abuse.
• Pregnant or lactating women. Pregnancy confirmed by a positive hCG test.
• Treatment with another investigational study drug in another clinical study within the last 30 days or five half-lives, whichever is longer.