Study of Arformoterol Tartrate Inhalation Solution and Racemic Formoterol in Subjects With Mild to Moderate Chronic Obstructive Pulmonary Disease (COPD)

Inclusion Criteria: * Male and female subjects must be at least 35 years old at the time of consent. * Female subjects less than or equal to 65 years old must have a negative serum pregnancy test at Visit 1 and a urine pregnancy test at Visit 2, confirmed negative prior to randomization. Subjects of childbearing potential must be using an acceptable method of birth control. * Subjects must have a documented primary clinical diagnosis of non-asthmatic COPD * Subjects must have a ≥ 15 pack-year smoking history * Subjects must be in general good health. * Subjects must have a minimum blood pressure of 105/60 mmHg and a minimum resting pulse of 50 bpm at Screening Visit 1. * Subjects must have a body mass index (BMI) of at least 16 kg/m2 but no more than 30 kg/m2. (BMI is defined as the subject's weight in kilograms divided by the square of the subject's height in meters.) * Subjects must be willing to remain in the residential facility for 3 separate 24 hour visits and 3 separate 36-hour visits. * Subjects must agree to refrain from strenuous activities, as defined by the Principal Investigator, throughout the study, from the screening visit until after the end of study/early termination visit. Exclusion Criteria: * Subject has had a febrile illness within 72 hours (3 days) before Screening. * Subject has any clinically significant unstable medical abnormality, chronic disease, or a history of a clinically significant abnormality of the cardiovascular, respiratory, gastrointestinal, hepatic, or renal systems, which, in the opinion of the investigator, may affect the safety of the subject. * Subject has a history of malignancy or currently has malignancy other than non melanomatous skin cancer. Subjects who have been cancer-free for 5 years or more may be enrolled. * Subjects with a chest x-ray that suggests a diagnosis other than COPD (e.g., diagnostic of pneumonia, other infection, atelectasis, or pneumothorax or other active/ongoing pulmonary conditions) and taken within 6 months prior to study start. If there is no chest x-ray taken within 6 months prior to study start, or if recent results are unavailable for review, a chest x-ray must be performed. * Subjects with a history of asthma, with the exception of asthma diagnosed in childhood. * Subject tests positive at screening for hepatitis B surface antigen or hepatitis C antibody, or the subject has a history of a positive result. * Subject is known to be seropositive for human immunodeficiency virus (HIV). * Female subject is pregnant or lactating. * Female subject who (a) is of childbearing potential and not using contraception or is using hormonal contraception, or (b) is post-menopausal and is taking any form of hormone replacement therapy. * Subject has a disorder or history of a condition that may interfere with drug absorption, distribution, metabolism, or excretion (e.g., malabsorption, gastrointestinal surgery). * Subject has participated in any investigational study within 30 days prior to screening or is currently participating in another clinical trial. * Subject is a staff member or relative of a staff member. * Subject has a positive urine alcohol test during screening. Subjects with a known history of alcohol use may be enrolled in the study if the subject's alcohol use is not indicative of abuse. Abuse is defined as current consumption of more than three alcoholic beverages per day. * Subject has a history or suspected history of abuse of a barbiturate, amphetamine, or narcotic and/or has a positive screening result for any of these substances at study start. * Subject has a history of allergic reaction to the study medication or any components of the study medications. * Subject has received oral anticoagulant therapy within 90 days before Screening. * Subject has had significant blood loss (\>500 cc) or donated blood within 60 days preceding screening or plans to donate blood during or within 60 days after completing the study. * Subject has donated plasma within 72 hours prior to the first dose of study drug. * Subject has had an acute illness within 10 days of Day 1.