Gastrointestinal Transit of Amoxicillin Modified-Release Tablets and a Placebo Tablet Including Pharmacokinetic Assessments of Amoxicillin

Abstract

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 modifiedrelease 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 (2.9–6.9h) 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.

Key Words:

• Absorption
• amoxicillin
• controlled release
• gamma scintigraphy
• gastric emptying
• Helicobacter pylori
• modified release
• ulcer disease