Search

Background: We have investigated the gastrointestinal transit time of, the influence of food intake on, the disintegration of, and the pharmacokinetics of amoxicillin in a modified-release form., Methods: Radiolabelled modified-release tablets of amoxicillin and placebo tablets were administered, in an open three-way, randomized, crossover design, as single doses during omeprazole treatment, to six male healthy subjects during fasting and non-fasting conditions. Radioscintigraphic images and plasma samples were obtained., Results: The estimated mean (and range) gastric emptying time of the modified-release tablet after drug administration was 0.3 h (0.1-1.0 h) during fasting conditions, 4.3 h (1.7-5.0 h) after a light breakfast, and 4.9 h (1.9-18.0 h) after a heavy breakfast. The small-intestinal transit time during fasting conditions was 4.7 h (2.9-6.9 h) and was not significantly changed after light or heavy breakfast intake. The relative bioavailability of the modified-release tablet was 55%, compared with a commercially available amoxicillin immediate-release tablet., Conclusion: The modified-release tablet of amoxicillin administered postprandially apparently increases the amoxicillin release time in the stomach. The relevance of its use for anti-H. pylori treatment can be questioned.

The gastrointestinal transit and tablet erosion of felodipine extended release (ER) tablets 10 mg were studied by gamma scintigraphy in eight healthy young males after administration under fasting and nonfasting conditions. Plasma concentrations of felodipine were also measured. Gastric emptying after administration together with food (mean, 3.2 hr) was slower in all subjects compared to emptying under fasting conditions (mean, 0.6 hr). The mean small intestinal transit times for the two study conditions did not differ significantly (5.1 and 4.7 hr, respectively). Tablets did not leave the colon in any subject within 14 hr after administration. Felodipine was shown to be absorbed in the colon, although the major part of the dose was absorbed in the small intestine. The absorption rate of felodipine was related to erosion of the hydrophilic matrix tablet. Tablet erosion and hence drug absorption were slower in the more distal parts of the gastrointestinal tract. Administration together with food did not significantly affect tablet erosion.