Studies of neutralizing properties of antacid preparations. Part 3: Constant pH neutralization of hydrochloric acid by hydrotalcite.

The neutralization reaction of hydrochloric acid by powdered hydrotalcite (HT) was studied by pH-stat method in the range of pH from 3.0 to 4.8. The neutralization process was examined by monitoring the appearance of aluminium and magnesium ions in the reaction medium, by determination of the chloride concentration in solution and by IR analysis of partially neutralized HT. The mechanism of acid neutralization of HT is discussed.