A crossover study after oral and intravenous administration of theophylline in male volunteers (absolute bioavailability of Afonilum tablets).
Seven normal male volunteers received an injection of 208 mg theophylline-anhydride (Solosin) each for 4 min, and a 225-mg single oral dose (Afonilum) on separate occasions. The concentration of unchanged theophylline was analyzed over a 24-h period in plasma and over a 48-h period in urine, after both dosage forms. A two-compartment model was required to describe the i.v. plasma concentration-time course in all seven subjects. A one-compartment model sufficed to account for the decay of the oral plasma concentrations in five of the subjects. The mean plasma t 1/2 after i.v. dosing was 6.5 h (3.5-9 h), and the mean plasma t 1/2 after oral doses was 5.9 h (3-8.3 h). The calculated mean total of 23% (11-70%) of the i.v. dose was excreted in the urine, and the mean total excretion after the oral dose was 15% (7-44%). The absolute bioavailability of Afonilum was 108 +/- 11%.
D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D013806:Theophylline / Q000008:administration & dosage* / Q000378:metabolism
D013806:Theophylline