The goal of this clinical trial is to compare the acute bronchodilator effect of the Ipratropium / Levosalbutamol 1.25 mg & 0.5 mg / 2.5 mL fixed dose combination nebuliser solution or Levosalbutamol 1.25 mg / 3 mL nebuliser solution and Ipratropium 500 mcg nebuliser solution in stable moderate-severe-very severe COPD patients.

Inclusion Criteria:

• Male or female patients aged 40 years and older who have been newly diagnosed or followed up with a diagnosis of COPD.
• Stable moderate-severe-very severe COPD patients with a post-bronchodilator FEV1/FVC ratio <70% and a postbronchodilator FEV1 value <80% at the screening visit will be included in the study.
• Symptom status such as chronic cough, sputum production, and progressive dyspnea with the BCSS (Breathlessness, Cough and Sputum Scale) Index will be evaluated, and the COPD staging of the patient with CAT (COPD Assessment Test) and the severity of dyspnea with mMRC (Modified Medical Research Council) will be determined.
• Patients with at least 10 pack/year smoking status or smoking history (patients who have quit smoking for at least 6 months or more are defined as ex-smokers).
• Patients who have not experienced an exacerbation in the previous 4 weeks.
• If the study participant is female; women using appropriate contraception (pregnancy test will be performed at screening visit).
• Patients with the ability to communicate with the investigator.
• Patients who accept to comply with the protocol.
• Patients who sign written informed consent form.

Exclusion Criteria:

• History of hypersensitivity to anticholinergics or SABAs (short acting beta agonist).
• History of COPD exacerbation or lower respiratory track infection that required treatment with antibiotic, oral or parenteral corticosteroid within the last 3 days 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.
• 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.
• Use of beta-blocker, monoamine oxidase (MAO) inhibitor or tricyclic antidepressant within the last 30 days prior the screening visit
• Recent (within ≤3 months 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 pressure) 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
• Presence of active cancer
• 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.