Characterization of the Contents of Ascending Colon to Which Drugs are Exposed After Oral Administration to Healthy Adults

Abstract

Composition of fluids in the ascending colon is affected by feeding. This may affect the performance of products designed to deliver drug to the colon.

Precipitation in and Supersaturation of Contents of the Upper Small Intestine After Administration of Two Weak Bases to Fasted Adults

“…DPD and KCZ were assayed with HPLC-UV methods that were based on previously published methods (6). Individual bile salts, lecithin, cholesterol, free fatty acids and monoglycerides were assayed with HPLC-CAD methods (10,11). Total protein content was determined using a commercially available kit (BCA TM Protein Assay Kit, Thermo SCIENTIFIC, Rockford, USA).…”

An Automated System for Monitoring and Regulating the pH of Bicarbonate Buffers

“…The pH of the luminal fluids in the intestines ranges from pH 5 up to 8.5 and depends on the GI segment and the prandial conditions (1,2). Contents of the small intestine are buffered mainly by bicarbonate ions, which are secreted by the pancreas and intestinal epithelial cells.…”

Characterization of the Ascending Colon Fluids in Ulcerative Colitis

“…Patient work-up prior to either phase involved the administration of 10 mg of bisacodyl 50 h prior to colonoscopy plus 10 mg of bisacodyl 44 h prior to each colonoscopy. With this regimen, bisacodyl effects on the intracolonic environment have been shown to be non-significant (7). One patient received an additional 5 mg bisacodyl tablet 30 h prior to each colonoscopy.…”

“…The collection lasted approximately 10 min. This period was sufficient to remove almost all of the contents from the region (7). After removal of the colonoscope, 2 mg of flumazenil (0.1 mg/ml, Anexate ® ) was administered as antidote to midazolam.…”

“…To date, apart from luminal pH (6), the physicochemical characteristics and composition of fluids in the ascending colon of adults with ulcerative colitis have not been investigated. Since bioavailability and bioequivalence studies are typically performed in healthy adults, the second objective was to identify differences in the characteristics and composition of fluids in the ascending colon between ulcerative colitis patients and healthy adults (7). To be able to make the second comparison, colon preparation and collection of colonic contents was done as in our recently published work in fasted healthy individuals (7).…”