A physicochemical study of SDS in aqueous solution of Furosemide: Effect of DMSO on surfactant-Furosemide interaction

• κ, η, v and d measurements were carried out in aqueous solutions of DMSO containing Furosemide.
• ΔHmo and ΔSmo values suggests that the micellization of SDS tends to be energy driven in the presence of DMSO.
• Studies reveal the formation of strong drug–DMSO complex.
• DMSO has a profound influence on the micellar properties of ionic surfactant.

Micellization behaviour of sodium dodecyl sulphate (anionic surfactant) has been studied in the presence of Furosemide (cardiovascular drug) at two concentrations i.e. 0.001 and 0.002 M in 8.0 mol% aqueous solution of dimethylsulphoxide using conductance (κ), densities (d), velocities of sound (v) and viscosities (η) studies in the temperature range 20–40 °C at an interval of 5 °C. The critical micelle concentration (cmc) of sodium dodecyl sulphate (SDS) was determined from the plots of specific conductance (κ  ) of SDS. The results showed that critical micelle concentration (cmc) values of surfactant decrease with increase in [Furosemide] and increase with the rise in temperature. By using cmc data, various thermodynamic parameters like standard enthalpy of micellization (ΔHmo), standard entropy of micellization (ΔSmo) and standard free energy of micellization (ΔGmo), that have direct bearing on the consequences of such interactions at the molecular level have been calculated. The apparent molar volume (ϕv) and apparent molar adiabatic compressibility (ϕκ) have also been computed using densities and velocities of sound data. The above calculated parameters were found to be sensitive towards the interactions prevailing in Furosemide–SDS–DMSO-water systems.