The objective of this study is to compare the bronchodilator efficacy a of tiotropium inhalation via DISCAIR (18 mcg once daily) and SPIRIVA HANDIHALER® (18 mcg once daily) in patients with moderate to severe chronic obstructive pulmonary disease (COPD).

Inclusion Criteria:

• Patients aged 40 years and older with moderate to severe COPD diagnosis
• Current/former smokers with at least a 10 pack-year history of cigarette smoking
• Patients with established clinical COPD and severity defined as a post-broncodilator FEV1/FVC ratio of ≤0.70 and FEV1 ≤80 % of predicted normal at screening
• Females of non-child bearing potential or females of child bearing potential with negative pregnancy test; and acceptable contraceptive methods
• Have no excacerbation within last 4 weeks
• Hava capability of communicate with investigator
• Accept to adapt the procedures of study protocol
• Signed and dated informed consent

Exclusion Criteria:

• History of hypersensitivity to anticholinergics
• Diagnosis of asthma
• History of alergic rinit and athopy
• Current or history of lung cancer
• Known symptomatic prostatic hypertrophy requiring drug therapy
• Known narrow-angle glaucoma requiring drug therapy
• Have experienced exacerbation of COPD or lower respiratory inflammatory disease requiring use of antibiotics, oral or parenteral corticosteroids (CS) within 4 weeks prior to screening visit and/or during run-in period
• Patients vaccinated with poored virüs vaccinate within 2 weeks prior to screening visit and/or during run-in period
• Patients with a recent history of myocardial infarction, acute ischemic cardiac disease or severe cardiac arrhythmia requiring drug therapy
• Women who are pregnant or lactating or are planning on becoming pregnant during the study