Facilitated transport across liquid/liquid interfaces and its relevance to drug diffusion across biological membranes

Abstract

The rotating diffusion cell has been used to study the facilitated transport of a dianionic dye, Resorcin Brown R, across a solid-supported liquid membrane. A pH gradient provides the chemical driving force for the co-transport mechanism. The carrier molecules incorporated into the liquid membrane were hydroxypropylamines and hydroxybutylamines. The transport mechanism was shown to be saturable. The amines also transported salicylate anions, and the proposed mechanism may be suitable for transporting anionic drug molecules across biological membranes. A further commercially available amine, Ethomeen S12, was also found to be capable of increasing the flux of salicylate across lipid membranes, and this compound may have potential in skin preparations.