In vitro adsorption of bile salts and aspirin to sucralfate.

Sucralfate, an aluminum salt of sulfated sucrose, is a new drug designed for the treatment of peptic ulcer. Sucralfate has been reported to be useful in a variety of situations including prevention of aspirin-induced gastric mucosal damage. We investigated the in vitro adsorption of bile salts or aspirin to sucralfate in environments simulating the stomach (pH 1.5), small intestine (pH 7), and colon (pH 7.8). Bile salts were incubated with sucralfate, and the quantity of bile salt adsorbed was calculated by subtraction from the amount remaining in solution after centrifugation at 12,500g for 30 min. Adsorption experiments were performed in bile salt solutions at pH 1.5 and 7.0 with 0-10 g/dl sucralfate using glycocholate, glycochenodeoxycholate, taurocholate, taurodeoxycholate, or taurochenodeoxycholate. The dihydroxy-unconjugated bile salts, deoxycholic, and chenodeoxycholic salts were tested at pH 7.8. Binding capacity (micromoles per gram sucralfate) was calculated from the linear regression of micromoles bound vs grams sucralfate incubated. Sucralfate adsorbed all bile salts tested (except taurocholic acid at pH 1.5) but was less effective than cholestyramine. Sucralfate does not adsorb sufficient bile salts at neutral pH to cause bile salt depletion. Aspirin was minimally adsorbed by sucralfate [7.5 mumol (1.4 mg)/g sucralfate, pH 1.5], and thus adsorption of aspirin does not explain the protective effect of sucralfate against aspirin injury.