Thermodynamic solution properties of pefloxacin mesylate and its interactions with organized assemblies of anionic surfactant, sodium dodecyl sulphate

This manuscript reports the physicochemical behavior of antibiotic amphiphilic drug pefloxacin mesylate (PFM) and its interaction with anionic surfactant, sodium dodecyl sulfate (SDS). The data of surface tension and electrical conductivity are helpful to detect the CMC as well as to calculate surface parameters, i.e. surface pressure, pi, surface excess concentration, Gamma, area per molecule of drug and standard Gibbs free energy of adsorption, Delta G(ads) and thermodynamic parameters like standard free energy of micellization, Delta G(m), standard enthalpy of micellization, Delta H-m and standard entropy of micellization, Delta S-m. The interaction of this drug with anionic surfactant, sodium dodecyl sulfate (SDS) was studied by electrical conductivity and UV/visible spectroscopy. This enabled us to compute the values of partition coefficient (K-x), free energy of partition, Delta G(p), binding constant, K-b, free energy of binding, Delta G(b), number of drug molecules per micelle, n, and thermodynamic parameters of drug-surfactant interaction. (C) 2013 Elsevier B.V. All rights reserved.