X-ray studies on phospholipid bilayers. VIII. Interactions with chlorpromazine.HCl.

Chlorpromazine is a widely used phenothiazine tranquilizer known to alter the shape of normal erythrocytes and their osmotic fragility. In order to understand the nature of the interactions chlorpromazine.HCl (CPZ.HCl) was made to interact with phospholipid bilayers formed by dimyristoylphosphatidylethanolamine (DMPE) and dimyristoylphosphatidylcholine (DMPC). This study was carried out by X-ray diffraction on crystalline powders of various molar mixtures of CPZ.HCl with DMPE and DMPC, with and without water. It was found that CPZ.HCl significatively affects the bilayer structure of DMPC in the presence of water, but not that of DMPE.