Micellization behavior of mixtures of amphiphilic promazine hydrochloride and cationic aniline hydrochloride in aqueous and electrolyte solutions

Abstract

We studied the influence of cationic hydrotrope aniline hydrochloride on the micellization behavior of cationic amphiphilic phenothiazine drug promazine hydrochloride in the presence and absence of 50mmol kg−1 NaCl. The experimental critical micelle concentration (CMC) values came out to be lower than ideal CMC (CMC id ) values, signifying attractive interactions between the two components in mixed micelles. NaCl further decreases the CMC of pure PMZ and aniline hydrochloride as well as their mixture due to screening of the electrostatic repulsion among the polar head groups. The bulk properties of solution were examined by using different theoretical models for justification and comparison of results. The micellar mole fraction of aniline hydrochloride (X1 Rub , X1 M , X1 Rod and X1 id ) was evaluated by different proposed models, showing greater contribution of hydrotrope in mixed micelle. The negative values of interaction parameter (β) indicate synergistic interactions and negative values of β further decrease by the addition of salt in mixed systems. From the CMC values as a function of temperature, various thermodynamic properties have been evaluated and discussed in detail.