Food does not effect in bioavailability of theophylline from Theolin Retard

The absorption of theophylline from a sustained release tablet preparation ( Theolin Retard 300 mg) was studied in 10 subjects both when fasting and immediately after a standardized breakfast. Intravenous aminophylline was used as the reference material. Food did not influence the absorption from Theolin Retard. The bioavailability was complete (93% after 30 h) both with and without food, and no difference was found in the time to peak of the plasma concentration curve (7 h), or the mean residence time (14 h). The absorption characteristics, with predominantly zero order kinetics, did not change with concomitant intake of breakfast.