Efficacy, Pharmacokinetics and Safety Comparison of Salmeterol Inhalation Powder Administered Via the HandiHaler® 2 and Serevent® Diskus® in Patients With Chronic Obstructive Pulmonary Disease (COPD)

Inclusion Criteria: * All patients must sign an informed consent consistent with International Conference on Harmonization Good Clinical Practice (ICH-GCP) guidelines and local legislations prior to any study-related procedures, which includes medication washout and restrictions * All patients must have a diagnosis of chronic obstructive pulmonary disease and must meet the following spirometric criteria: * Patients must have relatively stable\* airway obstruction with a pre-dose FEV1 ≤ 60% of predicted normal and FEV1 ≤ 70% of FVC at Visits 1 and 2. * \*The enrolment of patients who have had an exacerbation within six weeks prior to planned study entry should be postponed * At Visit 1, patients must demonstrate an improvement in FEV1 of ≥ 12% over the pre-bronchodilator value 45 minutes after inhalation of 4 puffs of 100 μg salbutamol (Sultanol® MDI) * Male or female patients 40 years of age or older * Patients must be current or ex-smokers with a smoking history of more than 10 pack-years ((Patients who have never smoked cigarettes must be excluded) * Patients must be able to perform technically acceptable pulmonary function tests during the study period as required in the protocol * Patients must be able to inhale medication in a competent manner from the HandiHaler® 2 device and the Diskus® device Exclusion Criteria: * Patients with significant diseases other than COPD will be excluded. A significant disease is defined as a disease which in the opinion of the investigator may either put the patient at risk because of participation in the study or a disease which may influence the results of the study or the patient's ability to participate in the study * Patients with a recent history (i.e., six months or less) of myocardial infarction * Patients who have been hospitalized for heart failure (New York Heart Association (NYHA) class III or IV) within the past year * Patients with any unstable or life threatening cardiac arrhythmia or cardiac arrhythmia requiring intervention or a change in drug therapy within the past year * Patients with malignancy for which the patient has undergone resection, radiation therapy or chemotherapy within the last five years. Patients with treated basal cell carcinoma are allowed * Patients with a history of asthma, allergic rhinitis or atopy or who have a total blood eosinophil count ≥600/mm3 * Patients with a history of life threatening pulmonary obstruction, or a history of cystic fibrosis or clinically evident bronchiectasis * Patients with known active tuberculosis * Patients with significant alcohol or drug abuse within the past two years * Patients who have undergone thoracotomy with pulmonary resection. Patients with a history of thoracotomy for other reasons should be evaluated as per exclusion criterion No. 1 * Patients who have completed a pulmonary rehabilitation program in the six weeks prior to the Screening Visit (Visit 1) or patients who are currently in a pulmonary rehabilitation program that will not be maintained throughout the duration of the study * Patients who regularly use daytime oxygen therapy for more than one hour per day and in the investigator's opinion will be unable to abstain from the use of oxygen therapy * Patients who are being treated with antihistamines (H1 receptor antagonists), antileukotrienes or leukotriene receptor antagonists for asthma or excluded allergic conditions * Patients who have been treated with cromolyn sodium or nedocromil sodium within one month prior to Visit 1 or during the run-in period * Patients using oral corticosteroid medication at unstable doses (i.e., less than six weeks on a stable dose) or at doses in excess of the equivalent of 10 mg of prednisone per day or 20 mg every other day * Patients with known hypersensitivity to beta-adrenergics, lactose or any other components of the inhalation capsule delivery system or the Diskus® * Pregnant or nursing women or women of childbearing potential not using a medically approved means of contraception for the previous three months (i.e. oral contraceptives, intrauterine devices, diaphragm or subdermal implants, e.g.: Norplant®) * Patients who have taken an investigational drug within one month or six half lives (whichever is greater) prior to Visit 1 * Patients who have been treated with oral beta-adrenergics within one month prior to Visit 1 or during the run-in period * Patients who have been treated with theophylline preparations within one month prior to Visit 1 or during the run-in period * Patients who have been treated with the long-acting anticholinergic tiotropium (Spiriva®) within one month prior to Visit 1 or during the run-in period * Patients with any respiratory infections in the six weeks prior to the Screening Visit (Visit 1) or during the run-in period. In the case of a respiratory infection during the run-in period the latter may be extended up to six weeks * Patients who are currently participating in another study