Thermodynamic studies on mixed micellization of amphiphilic drug amitriptyline hydrochloride and nonionic surfactant Triton X-100

► Surface properties and mixed micellization studies of drug AMT with surfactant TX-100 using surface tension measurements. ► The cmc of AMT with or without TX-100 were measured and the Γmax and the Amin parameters were evaluated. ► Γmax increases and cmc as well as Amin decrease with increasing concentration of TX-100. ► The thermodynamic parameters of AMT with or without TX-100 were evaluated. ► Gibbs energies (viz., Gmin(s), ΔmicG0, ΔadsG0, ΔGexm) were evaluated and found mixed systems are more stable.