Studies on the in vitro interactions of cimetidine with commercial antacid preparations and chemically pure components.

Studies of the in vitro binding of cimetidine to commercial antacid preparations such as colloidal aluminium hydroxide-magnesium hydroxide, aluminium hydroxide-calcium carbonate and the chemical pure components Al(OH)3, Mg(OH)2 or Al2O3 showed no adsorption of cimetidine at cimetidine to antacid ratios employed in clinical practice. Small degrees of binding were observed with two silicate containing antacids (21.4 +/- 0.5 mumol/g and 12.3 +/- 1.9 mumol/g).