Interaction of cetyltrimethylammonium bromide with cefixime trihydrate drug at different temperatures and compositions: Effect of different electrolytes

Abstract Herein, conductivity measurements have been carried out to explore the interaction between cetyltrimethylammonium bromide (CTAB, a cationic surfactant) and antibiotic drug (cefixime trihydrate (CMT)) in water and also in occurrence of inorganic salts (NaCl, Na 2 SO 4 and Na 3 PO 4 ) over the temperature range of 303.15–323.15 K with an interval of 5 K. In all cases, two critical micelle concentrations ( c ⁎ ) were achieved for the CMT-surfactant system. Addition of CMT drug to CTAB solution decreases the values of c ⁎ which indicates the interaction between CMT and CTAB. Both values of c ⁎ for CMT-CTAB mixture in presence of salts are lower in magnitude compared to the aqueous medium which indicates that micellization of the CMT-CTAB mixed system is favorable in salts solution. The values of ∆  G 0 m were obtained to be negative indicating the spontaneity of the micellization process and the extent of spontaneity further increases by means of rising temperature. The obtained outcomes from the ∆  H 0 m and ∆  S 0 m values disclose that the interactions between CMT and CTAB are mostly electrostatic along with hydrophobic in nature. The thermodynamic parameters of transfer and enthalpy-entropy compensation phenomenon were also determined and discussed in detail.