Intestinal absorption of a new anticholinergic agent, timepidium bromide. I. Various factors influencing absorption.

Abstract

Various factors influencing intestinal absorption of a quaternary anticholinergic agent, timepidium bromide (TB), were studied in rats using in situ intestinal loop technique. Bile, mucin and intestinal mucous material significantly decreased the amount of TB absorbed from intestinal loops. This decrease was assumed to be due to bonding of TB cation to anionic groups of bile constituents, mucin and intestinal mucous membranes. Gastric juice and hydrochloric acid significantly increased the absorption of TB. Organic acids, such as citric, malic and acetic acid, also increased the absorption of TB. The greatest increase in absorption of TB was observed in the presence of citric acid. Citric acid had this facilitatory effect only when added to the medium in relatively high concentrations (0.05M) and at relatively low pH. However, this increased absorption was shown not to be simply the result of an acidic intestinal environment or irreversible changes in the gut wall.