CMC determination and thermodynamic changes of the mixture of mefenamic acid drug with surfactant (Tween 60, Tween 80, And TritonX-100) in aqueous solution

Abstract

Surface tension of non-steroidal anti-inflammatory drugs (NSAIDs) such as mefenamic acid was measured at concentrations (10-1, 10-2, 10-3, 2x10-3M) carrying the surfactant active agent such as sorbitan monostearate (Tween 60) and Oxyethylene (20) sorbitan mononuclear (Tween 80) as well as with (Triton X-100) at concentrations from 10-1M to 10-4M using a plate-type tensiometer, as well, the effect of temperatures at (323,313,303,293) K were studied. The critical micelle concentration (CMC) was evaluated from the plot of surface tension with the concentrations, and the thermodynamic constants were estimated at CMC such as the change in enthalpy heat content (ΔH°m), the change in the free energy of adsorption (ΔG°ads) and the change in free energy for the formation of micelles (ΔG°m) as well as the change in entropy (ΔS°m).