Effect of antidiabetic metformin hydrochloride on physicochemical properties of cationic surfactant cetyltrimethylammonium bromide in aqueous solutions

In view of understanding the nature of molecular interactions between surfactant and drug, here we report the experimental conductance (kappa), densities (rho) and ultrasonic velocities (u) of cationic surfactant cetyltrimethylammonium bromide, CTAB (0.5 11 mM) in 2.0 mM aqueous solution of antidiabetic drug metformin hydrochloride as a solvent at different temperatures (303.15, 308.15, 313.15 K). The critical micelle concentration, cmc of CTAB in aqueous solution containing drug was determined from conductance and surface tension study at 298.15, 303.15, 308.15, and 313.15 K. From the experimental density and ultrasonic velocity data, properties such as apparent molar volume (V-2,V-phi), isentropic compressibility (kappa(S)), apparent molar isentropic compressibility (kappa(S,2,phi)), specific acoustic impedance (Z), relative association (R-A) were calculated and interpreted in terms of drug-surfactant interactions and effect of electrolyte drug on micellization of surfactant. Structural changes in studied solution due to presence of organic drug and temperature have been investigated. The thermodynamic properties of micellization like values of Delta G(m)(0), Delta H-m(0), and Delta S-m(0) were calculated. The thermodynamics of micellization has been found to be spontaneous, exothermic and entropy driven process.

Automated summary

The study investigated the molecular interactions between cationic surfactant CTAB and antidiabetic drug metformin hydrochloride in aqueous solution, calculating various properties from experimental data and observing the effects of drug and temperature on solution structure. The thermodynamics of micellization process was found to be spontaneous, exothermic, and entropy driven.