Conductometric and spectrophotometric studies of self-aggregation behavior of streptomycin sulphate in aqueous solution: Effect of electrolytes

Abstract

The effect of some electrolytes present in body fluid on micellar properties of the antibiotic drug streptomycin sulphate has been determined conductometrically over the temperature range 298.15–313.15 K with an interval of 5 K. The outcomes obtained from this study are further supported by fluorescence and UV measurements. The observed critical micelle concentration (CMC) data have been used to calculate standard thermodynamic parameters of micellization like free energy of micellization (ΔGmo), entropy change of micellization (ΔSmo), and enthalpy change of micellization (ΔHmo) for the aqueous solution of surface active drug streptomycin in the presence of various electrolytes. These parameters of micellization have been explored in terms of hydrophobic and hydrophilic interactions present in water–drug–electrolyte ternary system. The ΔGmo, ΔHmo, and ΔSmo values indicate that the electrolytes favor the aggregation behavior of the drug and process of micellization is well accommodated by enthalpy and entropy determinants. The interionic interactions have been elucidated by applying the model of pseudo phase separation.