Duolin Respules contain a combination of levosalbutamol and ipratropium bromide, two bronchodilators that work synergistically to open up the airways and improve breathing. Levosalbutamol acts quickly to relieve bronchospasm, while ipratropium bromide helps to reduce bronchial secretions, providing comprehensive relief for respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). The nebulizer delivery system ensures efficient administration, delivering the medication directly to the lungs for faster absorption and relief.