Relationships between octanol-water partition data, chromatographic indices and their dependence on pH in a set of beta-adrenoceptor blocking agents.

A thorough investigation on the dependence of octanol/water distribution coefficients (log D) of basic and amphiprotic beta-blocker drugs on pH and pKa values has been carried out. An attempt is made to clarify the factors which govern the chromatographic parameters (log k') in reversed-phase high performance liquid chromatography (RPLC) in terms of chemical structure and of distribution coefficients. The correlations between log D and log k' of different compounds show that the bulkiness and the branching of nitrogen substituent are controlling factors in RPLC measurements. Finally, an ion pair chromatographic system is considered for the prediction of octanol/water partition coefficients.