Effect of phenothiazines on viscosity and electrical stability of model phospholipid membranes

: The effect of five phenothiazine derivatives on the viscosity of model phospholipid membranes (by eximerization of pyrene) and on their electrical stability has been studied All the phenothiazines tested (chlorpromazine, propazine, triftazin and nonachlazine), except for chloracyzine, considerably increase the viscosity of phospholipid liposome bilayer at a concentration of 10(-5)-10(-4) M. Phenothiazines have been also shown to decrease liposome break-down potential even at a concentration of 10(-7) M. No correlation between the magnitude of break-down potential and changes in liposome membrane viscosity has been revealed.