Influence of NaCl and temperature on the interaction between cephradine monohydrate and surfactants: Conductivity and UV-visible measurements

The formulation of drug considering the body fluid ingredients is important and therefore study of the interaction of drug-surfactant in fluid ingredients medium is very significant. Herein, we applied a conductivity technique to insight the interaction of cephradine monohydrate (CDM) drug with cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant-sodium dodecyl sulfate (SDS)) while UV-visible spectroscopic was employed to observe the interaction of CDM with non-ionic surfactant, triton X-100 (TX-100). The experimental temperature ranges were 303.15-328.15 K and 293.15-323.15 K for CDM + CTAB and CDM + SDS systems respectively in the case of the conductivity study whereas for UV-visible spectroscopic study the temperature was kept in the range of 298.15-318.15 K. The values of critical micelle concentration (CMC) of CDM + CTAB and CDM + SDS systems were analyzed from their conductivity data in H2O and aqueous NaCl solution. The CMC values were found to be lower for CDM + CTAB and CDM + SDS systems as compared to corresponding pure surfactants. The CMC values were found to be influenced by the variation of experimental temperature. The micellization of CDM + CTAB and CDM + SDS systems was favored in the presence of NaCl and augmentation of NaCl concentration generates a more favorable condition for micellization of studied systems. The values of counter ion dissociation (alpha) were found to be temperature and additives dependent. The free energy of micellization (Delta G(m)(o)) indicates that micellization of CDM + CTAB and CDM + SDS systems was thermodynamically spontaneous which further augmented with the boost of NaCl concentration. The computed enthalpy and entropy values exhibit a linear relationship in all cases for CDM + CTAB and CDM + SDS systems. The binding constant (K-b) between CDMand TX-100 was found to be increased with the augmentation of CDM concentration and exhibit U-like variation as temperature increases. The binding between CDMand TX-100 was also thermodynamically spontaneous. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the interaction of a drug with surfactants in body fluid ingredients medium using conductivity and UV-visible spectroscopic techniques. The addition of NaCl was found to promote micellization of the systems and the critical micelle concentration was influenced by experimental temperature. The binding between the drug and surfactants was thermodynamically spontaneous, with an increase in binding constant observed with higher drug concentration and temperature.