The Langmuir trough experiments were designed on the basis of the above observations.
Posa determined the hydrophobicity of sodium salts of CA, CDCA, DCA, HDCA, and UDCA in chromatographic experiments [57] and the change in the chromatographic retention index values ([R.sub.M0]) follows in principle the order observed by us for the energies of association due to hydrophobic interaction in the Langmuir trough experiments.
The Langmuir trough experiments performed systematically on the series of bile acids and derivatives can be used to select appropriate molecules for specific aims, such as drug delivery vehicles or drug uptake enhancers.