Influence of food on the rate and extent of absorption of theophylline after single dose oral administration of a controlled release tablet.

Rate and extent of absorption of theophylline were determined in 7 healthy volunteers on pre- as well as on postprandial administration of commercially available controlled release tablets (Theograd-350 mg). In fasting subjects, maximum serum theophylline concentrations of 3.8 +/- 1.2 mg X 1(-1) (mean +/- SD) were reached at 3.4 +/- 1.2 hours after dosing, whereas under non-fasting conditions maximum serum levels of 5.8 +/- 1.3 mg X 1(-1) were found at 7.4 +/- 1.4 hours after the tablet was given. The bioavailability increased from 65 +/- 8%, observed on preprandial administration to 87 +/- 14%, when Theograd-350 mg tablets were taken after a meal. In conclusion, Theograd-350 mg tablets have a predictable absorption and give relatively high (87%) bioavailability, if the tablets are taken after a meal.