Self-association of amphiphilic phenothiazine drugs in aqueous solutions of low ionic strength

Abstract

Osmotic coefficients have been derived from freezing point determinations on aqueous solutions of the amphiphilic drugs, chlorpromazine and promethazine hydrochloride, in the presence of low concentrations of added electrolyte (0.01–0.05 mol kg^–1 NaCl). Aggregation numbers predicted by the application of a mass action theory to the osmotic data were in agreement with experimental values determined by time-averaged light scattering methods.