An in Vitro Study of Antacids: Methods and Modifying Factors

The in vitro conditions reported were arbitrarily established to permit a comparison of various methods and of various media for checking antacids. The data cannot be interpreted in terms of in vivo conditions because of the large number of biological variables. Three widely used in vitro antacid evaluation methods were examined using seven representative commercial antacid preparations. Each of the three methods gave different results, although the same order of in vitro effectiveness is maintained regardless of the method used. A comparative study was made of various simulated gastric juices and pooled human gastric juice. The addition of mucin to U. S. P. simulated gastric juice gave a titration curve and antacid response similar to that of human gastric juice.