Acute Bronchodilator Effects of Ipratropium/Levosalbutamol 20/50 mcg Fixed Dose Combination vs Salbutamol 100 mcg Inhaler Plus Ipratropium 20 mcg Inhalation Aerosol Free Combination in Patients With Stable COPD

Inclusion Criteria: * Female and male patients aged ≥40 years diagnosed with symptomathic stable moderate-severe-very severe COPD: post-bronchodilator FEV1/FVC \<70% predicted and a post-bronchodilator FEV1 \<80% predicted at screen visit. Group B COPD CAT: ≥10 or mMRC: ≥ 2 Exacerbation: 0-1 (not leading to hospital admission) Group C COPD CAT: \<10 or mMRC: 0-1 Exacerbation: ≥2 (not leading to hospital admission) or ≥1 (leading to hospital admission) Group D COPD CAT: ≥10 or mMRC: ≥ 2 Exacerbation: ≥2 (not leading to hospital admission) or ≥1 (leading to hospital admission) * Current or ex-smokers with a smoking history of at least 10 pack-years * Patients who have no exacerbation within the last 4 weeks * Female patients who use effective contraception * Patients who have a capability to communicate with investigator * Patients who accept to comply with the protocol * Patients who sign written informed consent form Exclusion Criteria: * History of hypersensitive to anticholinergics or SABAs * History of COPD exacerbation or lower respiratory track infection that required treatment with antibiotic, oral or parenteral corticosteroid within the last 4 weeks prior the screening visit or during the run-in/wash-out period or history of respiratory tract infection that required treatment with antibiotic within the last 14 days prior the screening visit. * Hospitalization due to COPD or pneumonia within the last 3 mounts prior the screening visit * Use of oral corticosteroid at unstable dosages (i.e. \<6 weeks on a stable dose of prednisone) * SGOT (serum glutamic oxaloacetic transaminase) \>80 IU/L, SGPT (serum glutamic pyruvic transaminase) \>80 IU/L, bilirubin \>2.0 mg/dL or creatinine \>2.0 mg/dL * History of asthma, significant chronic respiratory diseases (i.e., significant bronchiectasis, interstitial lung diseases, etc.) other than COPD or presence of disease that may be serious and/or potentially affect results of the study. * Initiation of an inhaled steroid or change in dose within \<6 weeks prior the screening visit * Use of beta-blocker, monoamine oxidase (MAO) inhibitor or tricyclic antidepressant within the last 30 days prior the screening visit * Recent (within ≤1 year prior the screening visit) history of heart attack, heart failure, acute ischemic heart disease or presence of serious cardiac arrhythmia requiring drug treatment * Regularly use of daytime CPAP (continuous positive airway measure) oxygen therapy for longer than 1 hour per day * Initiation of pulmonary rehabilitation within the 3 months prior the screening visit * History of lung volume reduction surgery * Drug or alcohol abuse * Presence of active tuberculosis * History of atopy or allergic rhinitis * History of cancer within the last 5 years * Attenuated live virus vaccination within the last 2 weeks prior the screening visit or during the run-in/wash-out period * Pregnancy or lactation * Presence of known symptomatic prostatic hypertrophy requiring treatment * Presence of known narrow-angle glaucoma requiring treatment * Currently participating in another clinical trial or treatment with another investigational study drug within the last month or 6-half-lives, whichever is longer.