Doxofylline is a xanthine derivative and selective phosphodiesterase inhibitor used primarily as a bronchodilator in pharmaceutical formulations for treating respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). It relaxes airway smooth muscles, improves airflow, and exhibits anti-inflammatory properties with a lower incidence of cardiovascular side effects compared to theophylline. This high-purity compound (97.5-100%) is supplied as a white to off-white powder, suitable for use as an active pharmaceutical ingredient (API), research reagent, or intermediate in drug development and manufacturing.