The interaction and energetics of the mixture of SDS and paracetamol in presence of zinc sulfate in an aqueous media

Paracetamol (PCM) is one of the most commonly employed drugs for the treatment of fever and pain. The activity of the drug is dependent on the excipients utilized during formulation as well as on physiological conditions. Herein, the conductivity measurements are implied to deduce the possible molecular interactions occurring between sodium dodecyl sulfate (SDS) and PCM in the presence of ZnSO4 at various temperatures. The critical micelle concentration (cmc) of SDS was found to be lowered with the augmentation of PCM concentration. The cmc values of the SDS + PCM mixture were found to be reduced with the increase of temperature and concentration of ZnSO4. The counterion binding values were found to be temperature and additives dependent. The estimated values of free energies of micellization (Delta G(m)(o)) signify the spontaneous aggregation of SDS + PCM mixture in all media studied. The spontaneity of self-assembly for SDS + PCM mixture augmented at a higher temperature. The estimated values of enthalpy of micellization (Delta H-m(o)) and entropy of micellization (Delta S-m(o)) were positive throughout. The values of Delta H-m(o) and Delta S-m(o) exhibit excellent linearity. The values of different transfer energies, intrinsic enthalpies, and compensation temperature were also calculated and explained properly.

Automated summary

Paracetamol is commonly used for treating fever and pain, and its activity is influenced by excipients and physiological conditions. The study investigated molecular interactions between SDS and PCM in the presence of ZnSO4 at different temperatures using conductivity measurements, revealing temperature and concentration-dependent changes in critical micelle concentrations. Free energies of micellization indicated spontaneous aggregation of SDS + PCM mixture, with increasing spontaneity at higher temperatures. Enthalpy and entropy values were positive throughout, showing excellent linearity, and different transfer energies and compensation temperatures were also calculated and explained.