Abstract
The mixed micellization behavior of amitriptyline hydrochloride (AMT) with cetyltrimethylammonium bromide (CTAB) has been studied at different mole fractions in the presence of imidazolium based ionic liquid 1-butyl-3-methyl imidazolium hydrochloride (Bmim center dot Cl), by using electrical conductivity at different temperatures from 298 to 318 K. A shift in the T-max value (i.e., the temperature at which the cmc value is maximized) has been observed with the rise in CTAB mole fraction. Synergistic interaction is explained by the deviations in critical micelle concentration (cmc) from an ideal critical micelle concentration (cmc*) and micellar mole fraction (X-m) from ideal micellar mole fraction (X-ideal) values. The calculated thermodynamic parameters (viz., the standard Gibbs energy change, Delta G(m)degrees, the standard enthalpy change, Delta H-m degrees, and the standard entropy change, Delta S-m degrees) suggest the dehydration of hydrophobic part of the drug at higher temperatures in the case of AMT as well as in CTAB-AMT binary systems in the presence of Bmim center dot Cl, whereas the temperature at which dehydration occurs changes with the rise in the mole fraction of CTAB.