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 cmcid values indicate mixed micelle formation between the components and strong synergism is observed in the mixed systems. The micellar (actual) mole fractions of surfactants (χ1Rub, χ1M, χ1Rod and χ1id), calculated on the basis of different theoretical proposed models used in the present study, show greater contribution of surfactants in mixed micelles. Activity coefficients (f1 and f2) 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.
© 2013 by Walter de Gruyter Berlin Boston