Experimental and molecular dynamics studies of the effect of electrolytes on the interaction and energetics of the mixture of triton X-100 + metformin hydrochloride

The mode of interaction of surfactant with drug remains a keen interest in the research area owing to the improvement of drug carrier systems in therapeutic formulations. In order to investigate the drug-surfactant interactions between triton X-100 (TTX-100) and an antidiabetic drug metformin hydrochloride (MMH); the phase partitioning behavior (in aq. Na2SO4, Na3PO4, and sodium dodecyl sulfate (SDS)), micellization, as well as the molecular dynamics simulation of the TTX-100 and MMH drug mixture have been examined. The CP values of TTX-100 + MMH system have been detected to be lessened with the growing concentration of Na2SO4 and Na3PO4, where the CP values follow the order: CP (aq. Na3PO4) < CP (aq. Na2SO4). The introduction of SDS caused the enhancement of CP for the study system. The critical micelle concentration (CMC) for the TTX-100 + MMH mixture was determined using the absorbance vs. log [TTX-100] plot using the UV–Visible spectroscopic tool. The CMC values were attained to be heightened with the rising content of MMH and, thus, the presence of MMH disfavors the micelle growth of TTX-100. The free energy changes of clouding (ΔGc0) and micellization (ΔGb0) have been noticed as positive (nonspontaneous process) and negative (spontaneous process), respectively. The changes in standard enthalpy (ΔHc0), entropy (ΔSc0), thermodynamic transfer parameters (ΔGc,tr0, ΔHc,tr0, ΔSc,tr0), and the ΔHc0-ΔSc0 compensation factors were also computed and appropriately explained. The values of ΔHc0 and ΔSc0 recommend that the clouding of TTX-100 + MMH in aq. Na2SO4 and Na3PO4 is controlled by the enthalpy alone, while the process is controlled by the entropy in aq. SDS solution. In this process, the electrostatic interactions and hydrophobic force are recommended as core forces among the employed media. By applying the molecular dynamics simulation, the atomic-scale interactions between MMH and TTX-100 were unveiled, showing a strong correlation with the experimental outcomes.