Abstract
In the present study mixed micelles of the amphiphilic phenothiazine drug promazine hydrochloride (PMZ) and the anionic surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT) have been studied using conductometry at different compositions and temperatures in aqueous as well as aqueous electrolyte (25 mmol center dot kg(-1) NaCl) solutions to determine various physicochemical properties of the solutions. The experimental and ideal critical micelle concentration (CMC and CMC (id)) values suggest attractive interactions in PMZ-AOT mixed systems. The negative values of interaction parameter (beta) obtained from regular solution theory indicate synergistic interactions; the negative values of beta decrease further with the addition of salt. From the CMC values obtained as a function of temperature, various other thermodynamic properties have been evaluated.