Acid neutralization and bile acid binding capacity of hydrotalcite compared with other antacids: An in vitro study

Abstract

OBJECTIVE: Antacids are used worldwide for the treatment of acid‐related conditions such as heartburn and gastro‐esophageal reflux disease. The present study investigated the in vitro acid neutralization and bile acid binding capacities of hydrotalcite compared with other antacids that are available in Germany and China. It has been reported that hydrotalcite is effective in the treatment of bile reflux gastritis because of its binding capacity to bile acids.METHODS: Hydrotalcite and other preparations of antacids were tested in a comparative in vitro study. The neutralization properties were determined with static and dynamic tests (preliminary antacid test, acid neutralization capacity (ANC) test, Rossett‐Rice (RR) test) and the bile acid binding test with a standardized commercial test kit (Merckotest bile acids).RESULTS: In the static and dynamic tests hydrotalcite 500 mg and some other antacids, such as magaldrate, almasilate, algedrate Mg hydroxide, Ca/Mg carbonate and calcium carbonate, demonstrated favorable ANC reflected by rapid onset and long duration of action, and high buffering capacity. In the RR test, a hydrotalcite dose of 1000 mg was able to keep the pH level above 3 for 76.9 min. The bile acid binding capacity test yielded that hydrotalcite had the highest binding potential to taurodeoxycholic acid, a lipophilic bile acid associated with cell and mucosa toxicity.CONCLUSIONS: Hydrotalcite has a rapid onset of action, a high buffering capacity and a long duration of action. In particular, hydrotalcite binds cytotoxic bile acids. These pharmacochemical properties make hydrotalcite a most suitable antacid.