Voltammetry of drugs at the interface between two immiscible electrolyte solutions

In this review, the results of the electrochemical investigations made on the transfer of ionizable drugs at the interface between two immiscible electrolyte solutions (ITIES) in the last decade have been presented. In many of the studies, cyclic voltammetry has been used to investigate the transfer characteristics of the charged species and deduce their partition coefficients, which are very important parameters to infer the lipophilicity of drugs in biological systems. The electrochemical technique allows the precise determination of the distribution of ionic species between two phases in a wider pH range. Such studies point out the complexity of the distribution of ionizable compounds and offer a new approach to relate the structure of such compounds to their passive transport across biological membranes.