Gastric juice as a dissolution medium: surface tension and pH.

Aspirated gastric juice from eight patients was measured for surface tension, bile salt concentration and pH. Surface tension ranged between 35 and 45 mM/m, while pH was usually in the range 1-2 and bile salt concentrations were usually between 0 and 1 mM. No correlations were found between the three parameters. These findings suggest that the low surface tension of gastric juice cannot be attributed solely to refluxed bile salts. Once the source of the reduced surface tension is identified dissolution test media should be adjusted to represent these conditions.