Inspiratory Flow Rates Achieved by the COPD Patients Through Breezhaler®, Ellipta® and Handihaler® Inhaler Devices

Inclusion Criteria: \- Current or ex-smokers who have a smoking history of at least 10 pack years (e.g., 10 pack years = 1 pack/day × 10 years, ½ pack/day × 20 years, etc.). Note: A pack of cigarettes is equal to 20 cigarettes. Occasional smoking of cigars is not relevant to smoking history. An ex-smoker is defined as a patient who has not smoked for ≥6 months at screening. * COPD patients with moderate to very severe airflow limitation (spirometric classification: GOLD 2, 3 or 4) at time of screening, * Post-bronchodilator FEV1 \< 80% of the predicted normal, and * Post-bronchodilator FEV1/forced vital capacity (FVC) \<0.70. (Post-bronchodilator refers to 1 hour after sequential inhalation of 84 µg ipratropium bromide and 400 µg salbutamol) * Willing patients assessed as suitable by investigator to reproducibly perform inhalational manoeuvers through study devices as required by the standard protocol * Willing patients assessed as suitable by investigator to comprehend and follow the instructions for use of the inhalational devices to be tested in the study Exclusion Criteria: * Patients with a history of asthma or onset of respiratory symptoms prior to the age of 40 years * Use of short acting bronchodilating agent (SABA) as rescue (reliever) medication within 6 hours prior to or during inhalational profile assessments for the study \[Note: Use of rescue medication should not be restricted if patient feels the need of the rescue/ reliever medication because of the diseased state. Safety and disease management should be priority and the suitability of such a patient for the study or relevance of the (study) assessments done for the study should be reviewed, as appropriate.\] * Patients with any history of premature birth less than 33 weeks gestation or significant level of respiratory care including mechanical ventilation required as neonate affecting the respiratory tract or chronic lung diseases, which in the opinion of the investigator or designated study personnel at site may interfere with the study evaluation or optimal participation in the study. * Any major chronic illness including but not limited to a diagnosis of non-skin cancer, cystic fibrosis, bronchiectasis, α-1 anti-trypsin deficiency, myelomeningocele, sickle cell anemia, endocrine disease, congenital heart disease, unstable arrhythmia, congestive heart failure, stroke, severe hypertension, insulin-dependent diabetes mellitus, renal failure, liver disorders, immunodeficiency states, significant neurodevelopmental delay or behavioral disorders (excluding mild attention deficit hyperactivity disorder). * Patients who have had a COPD exacerbation that required treatment with antibiotics or oral corticosteroids or hospitalization in the 6 weeks prior to screening * Patients who, within 7 days prior to the screening visit (Visit 1) OR prior to Visit 2, increased use of rescue bronchodilators amounting to more than double the average number of puffs used in the preceding week or more than 8 puffs of SABA on any 3 consecutive days or more than 12 puffs of SABA on any 2 consecutive days * Respiratory tract infections (sinus, middle ear, oropharyngeal, upper or lower respiratory tract infection) within the 4weeks before the visit