Abstract
Imipramine hydrochloride (IMP) is a drug which is amphiphilic. Its interaction with gemini surfactants 14-s-14 (s=4, 5, 6) has been investigated at different temperatures employing conductimetric measurements. The experimentally determined critical micelle concentration (cmc) values come out to be lower than the ideal values (cmcid — the cmc value at ideal mixing state) suggesting attractive interactions between the mixture components. The micellar mole fraction of surfactant in the mixed systems (X1Rub, X1M, X1Rod, X1S and X1id), evaluated by applying various proposed models, shows greater contribution of the gemini surfactants in mixed micelles. Interaction parameters (β) come out to be negative which suggests synergism in the mixtures — this is highly beneficial as it reduces the total amount and hence the cost and environmental effect for use of the gemini surfactants in a particular application. The component activity coefficients (f1 and f2) are always less than unity showing nonideality in the systems. Thermodynamic parameters for the mixed micellization process have also been evaluated and discussed.
•Mixing behavior of amphiphilic drug-cationic surfactant systems has been investigated.•Rubingh, Motomura, Rodenas and Shinoda models show higher contribution of surfactants in mixed micelles.•The negative β values show attractive interactions between the drug and surfactants.