[In vitro determination of the neutralizing capacity of antacids]

The in vitro evaluation of antacids provides information about their therapeutic effectiveness. By testing the ability of antacids to buffer acid in vitro, the dependency of the neutralization or buffer capacity from the pH of the endpoint of titration should be taken into consideration. Practical and physiologic reasons suggest to use pH 3.5 as the standard reference value. Furthermore antacids, mostly those containing aluminum hydroxide, loose a considerable percentage of the buffer capacity, if they are tested in a protein solution. Finally, with regard to other indications for antacid therapy besides peptic ulcer disease like biliary reflux or alkaline gastritis, the individual ability of an antacid to bind bile acids should be tested in vitro.