[Study on the interactions during storage of compounds of the antacid group. I. Interactions of the components in suspensions].

Twenty antacid mixtures of six quality groups containing Al(OH)3, gel, Mg(OH)2, Mg2Si3O8, CaCO3 and NaAl(OH)2CO3 at different ratios were prepared and stored for 150 days at 20 degrees C in the form of aqueous suspensions. Changes of pH in the suspensions were measured, and the accompanying structural changes were examined by IR spectrometry and X-ray diffraction analysis. Hydrotalcite was found to be formed during storage of aqueous suspensions of mixtures of Al(OH)3 Mg(OH)2; Al(OH)3: Mg(OH)2: CaCO3; Al(OH)3: Mg(OH)2: NaAl(OH)2CO3 and Mg(OH)2: NaAl(OH)2CO3. Initial neutralization activities of the suspensions and those found after the storage were compared.