Guinea pig model for antibiotic transport across gastric mucosa: inhibitory tissue concentrations of clindamycin against Helicobacter pylori (Campylobacter pylori) following two separate dose regimens.

An animal model for antibiotic secretion across gastric mucosa was developed using adult guinea pigs. Antibiotics were given intramuscularly, and levels in serum and gastric mucosa were measured by high-pressure liquid chromatography at 1, 2, 4, 6, and 8 h postinjection. Mucosal levels of the drugs were measured in the superficial luminal portion of the mucosa, which was removed by mechanical scraping. Clindamycin levels were measured after doses of 10 and 100 mg/kg of body weight. After doses of 100 mg/kg, levels in serum peaked at 15.95 micrograms/ml at 2 h. Gastric mucosa showed a bimodal concentration curve with peaks of 15.91 micrograms/g at 1 h and 25.07 micrograms/g at 4 h. Concentrations in mucosa remained high when levels in serum fell, showing a mucosa/serum ratio of 87.70 after 8 h. At all times, clindamycin levels in mucosa were in excess of the MIC for 90% of the Helicobacter (Campylobacter) pylori strains tested.