Radiotelemetric comparison of two antacids using the Heidelberg capsule

The acid neutralizing capacity of a new antacid, almagate (hydrated aluminium-magnesium hydroxycarbonate, Al2Mg6(OH)14(CO3)2 X 4 H2O, Almax) has been compared with that of a popular mixture of aluminium-magnesium hydroxide codried gel, aluminium hydroxide and calcium carbonate (antacid A) using a transistorized telemetric technique (Heidelberg capsule) in 10 healthy volunteers following a double-blind crossover design. After placement of the radio transmitter capsule in the stomach a standard bicarbonate alkali test was made followed by the antacid under study. From the pH versus time curves obtained it was clearly shown that both antacid A and Almax produced a rapid (less than 1 min) neutralization of gastric acid (greater than pH 3) and that there were no significant differences between the two in terms of duration of effect (mean values of 48.35 and 54.65 min, respectively) and area under the pH versus time curves (mean values of 166.9 and 197.2 mm2, respectively). The maximum pH reached with Almax (mean 8.3) was, however, significantly (p less than 0.05) higher than that reached with antacid A (mean 7.6) although these maximum values were only transient. A calculation of antacid capacity relative to the bicarbonate alkali test control in each subject showed that Almax (5.75) had an apparently greater capacity than antacid A (3.33) but the individual variations were too great to allow statistical confirmation of this difference.