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

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, Na2SO4 and Na3PO4) 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 the 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 salt solution. The values of Delta G(m)(0) 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 Delta H-m(0) and Delta S-m(0) 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. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.