Doxofylline is a bronchodilator classified as a xanthine derivative. Doxofylline relaxes the smooth muscle of the bronchial airways and pulmonary blood vessels; main action is bronchodilation and anti-spasmodic; also contains anti-inflammatory properties. Puroxan is indicated for the treatment of bronchial asthma and chronic obstructive pulmonary disease (COPD) associated with bronchospasm.