Usefulness of Rosen's postulate for studying the relationship between the structure of cholic acid oxyethylation products and the process of solubilization of lipophilic therapeutic agents (BCS class II and IV) in aqueous solutions in equilibrium.

We verified the usefulness of "Rosen's postulate", i.e., the logarithm of reciprocal concentration of surfactant--log(1/cPi=20) by which the surface tension of a solution can be decreased by 20 mJ/m2 in relation to water (physiological value gamma25 = 48-52 mJ/m2) in the evaluation of the applicatory properties of cholic acid oxyethylation products. Moreover, the values of deltaG0m for solubilizers and their micellar adducts with diclofenac, naproxen, and loratadine constituted the basis for estimating the thermodynamic value of "Rebinder's effect", associated with change in the state of matter of therapeutic agent. We determined critical micellar concentration for the aqueous products of oxyethylation and for micellar adducts with diclofenac, naproxen, and loratadine, and used these values to calculate (thermodynamic potential of micelle formation).