In vitro buffering capacities of proprietary non-particulate antacids available in New Zealand

Four commercially available non-particulate antacid preparations were titrated against 1M hydrochloric acid to assess buffering capacity as compared to 30 ml 0.3M sodium citrate solution. All antacids were used in the manufacturers "unit dose". All antacids tested demonstrated some in vitro buffering capacity, and "Eno" (Reckitt and Colman) had a buffering capacity similar to that of sodium citrate. The retail cost per unit dose was established for each proprietary antacid and for sodium citrate. It was concluded that while proprietary antacids are cheaper per dose than sodium citrate, preparations differ in their acid-neutralising capacity.