Assessment of Bronchodilator Efficacy of Formoterol/Budesonide 12/400 mcg Via Discair in COPD

Inclusion Criteria: * Patients aged ≥40 years with newly or formerly diagnosed moderate to severe COPD (Patients with postbronchodilator FEV1/FVC ratio \<0.70, and FEV1 \<80% of predicted normal. Patients have chronic cough or chronic productive cough with breathlessness even walking slowly along flat ground.) Current smokers or exsmokers with a smoking history of at least 10 pack-years * Patients who have no exacerbation within last 4 weeks * Females patients with childbearing potential using effective birth control method * Patients who has a capability of communicate with investigator * Patients who accept to comply with the requirements of the protocol * Patients who signed written informed consent prior to participation Exclusion Criteria: * Patients who have history of hypersensitivity to drugs contains long-acting beta2-agonist or corticosteroids * Patients who have abnormal blood glucose level ((≥140 mg/dl) * Patients who have unregulated diabetes mellitus * Patients who have a serum potassium level of ≤3.5 mEq/L or \>5.5mEq/L * Patients who have asthma * Patients who have a history of myocardial infarction, severe hearth failure, acute ischemic coroner disease or severe cardiac arrhythmia requiring treatment within least 6 weeks * Patients who have lung cancer * Patients vaccinated with live attenuated vaccines within 2 weeks prior to screening visit or during run-in period. * Patients who had COPD exacerbation or lower respiratory track infections that required antibiotic, oral or parenteral corticosteroid treatment within 4 weeks prior to screening visit or during run-in period. * Women who are pregnant or nursing * History of allergic rhinitis or atopy