Effect of food on bioavailability and pharmacokinetics of theophylline following administration of two sustained release dosage forms: Part I.
Bioavailability and pharmacokinetics of theophylline following administration of a marketed sustained release tablet (Theo-Dur) and a newly designed sustained release tablet (E-0686) have been studied in fifteen healthy volunteers under overnight fasting and non-fasting conditions. Higher concentrations at early absorption phase under fasting conditions than under non-fasting conditions were observed after administration of Theo-Dur, whereas little difference in plasma concentrations was noted when E-0686 was administered under fasting and non-fasting conditions. Bioequivalency was demonstrated depending upon the extent of bioavailability of the two preparations. Compared to the theophylline levels in non-smokers, significantly lower concentrations at elimination phase and AUC0-infinity values were observed in smokers in each treatment (p less than 0.05). E-0686 exhibited almost the same rate constant in dissolution in vitro and in absorption in vivo, while Theo-Dur did not. Therefore, it may be concluded that E-0686 is a well-designed sustained release preparation that releases theophylline in vivo at a given rate which can be easily determined in vitro.
N
N
Ohmori
N
N
Inotsume
M
M
Matsukura
A
A
Higashi
R
R
Iwaoku
Y
Y
Tobino
M
M
Nakano
I
I
Matsuda
D000328:Adult; D001682:Biological Availability; D003692:Delayed-Action Preparations; D005502:Food; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D012907:Smoking; D013806:Theophylline / Q000008:administration & dosage / Q000378:metabolism*
D003692:Delayed-Action Preparations; D013806:Theophylline