Analysis of Mixed Micellar Behavior of Promazine Hydrochloride with Surfactants in Aqueous Medium at Different Temperatures and Compositions

Abstract Mixed micellization behavior of an amphiphilic phenothiazine drug promazine hydrochloride (PMZ) in the presence of conventional dodecyltrimethylammonium bromide (DTAB) as well as gemini 1,4-bis( N -dodecyl- N , N -dimethylammonium)butane bromide (12-4-12) cationic surfactants has been studied at four different fixed temperatures and compositions by conductometric technique. The experimental data have been analysed by considering different theoretical models of Clint, Rubingh, Motomura and Rodenas. The cmc and cmc id values indicate mixed micelle formation between the components and strong synergism is observed in the mixed systems. The micellar (actual) mole fractions of surfactants ( χ 1 Rub , χ 1 M , χ 1 Rod and χ 1 id ), calculated on the basis of different theoretical proposed models used in the present study, show greater contribution of surfactants in mixed micelles. Activity coefficients ( f 1 and f 2 ) are always less than unity indicating nonideality in the systems. Thermodynamic parameters are also evaluated and discussed which suggest that at higher temperatures dehydration of hydrophobic part of the drug takes place.