Exploration of Cloxacillin Sodium interaction with Aggregates of Benzimidazolium Gemini Surfactants: Spectroscopic and Biophysical Analysis

The interaction of benzimidazolium gemini surfactants viz. 1,3-bis-(1-octylbenzimidazolium) propane bromide, simply represented as BG8, and 1,3-bis-(1-decylbenzimidazolium) propane bromide (BG10) with an antibiotic drug cloxacillin sodium (CLX) was explored by surface tension measurements. Numerous interfacial parameters viz. minimum surface area per molecule ( A(min)), maximum surface excess concentration ( Gamma(max)), packing parameter (P) and thermodynamic parameters like Gibbs free energy of micellization (Delta G(m)(0) ), enthalpy of micellization (Delta H-m(0) ) and entropy of micellization (Delta S-m(0)) at different temperatures were observed. Steady-state fluorescence has been done for comprehension of micro-environment of the aggregates as well as to calculate the binding constants (K-b) and Gibbs free energy change (Delta G). Dynamic light scattering results gave evidence regarding the size of aggregates of CLX-BG complexes. Also, comparative studies by UV- visible, FTIR, (HNMR)-H-1, and viscometry have been done to further investigate the interaction of CLX with BG8/BG10 surfactants.