This work introduced a green spectrophotometric method based on the manipulation of the area under the curve named Area under the curve correction method (AUCCM). The method was applied for the characterization and evaluation the in-vitro release of two nanocarrier systems namely, nano-structured lipid carrier (NLC) and niosomal system of Simvastatin (SIM), through measuring free SIM in presence of the possible excipients/interferents (oleic acid and cholesterol) in a challenging matrix. The estimation of SIM was calculated using the area under the curve (AUC) in the wavelength range of (234.5 -245.5) nm which includes the λmax of SIM in the concentration range of (1-35 µg/mL). The method was validated in compliance with ICH guidelines. The greenness of the developed analytical method will be assessed and compared to other reported methods using the greenness assessment tools known as: National Environmental Methods Index (NEMI), Green Analytical Procedure Index (GAPI) and Eco-Scale. The method proved to be the best regrading greenness and and was successfully applied for the in-vitro release study of SIM from the two nano carrier systems.