Interfacial and thermodynamic properties Γmax, Amin, ᴨcmc , ΔG°ads, ΔG°m, ΔH°m, and ΔS°m of individual sodium octyl sulfosuccinate (AOT) surfactant and their mixture with (DPH) drug at two concentrations (0.001 and 0.0001 M) have been calculated. The calculation was performed using the surface tension at temperature range 293-323 K with the variation of surfactant concentration to determine the cmc of all systems studied. The variation of critical micelle concentration (cmc) with concentration of DPH drug and the temperature was used to calculate the parameters above. The results indicate that the cmc of AOT Decrease when the DPH was added and when the temperature increased at the whole temperature studied. The results obtained for interfacial properties show that Γmax decrease with the addition of DPH. The results of thermodynamic properties indicate that the micellization and adsorption at interface are spontaneous and the ΔG°ads are more negative than ΔG°m at all temperatures which reveal that micelle formation is less spontaneous than adsorption or surface adsorption is more preferable than micellization.