Validation of an Ultraviolet–visible (UV–Vis) technique for the quantitative determination of curcumin in poly(l-lactic acid) nanoparticles

•Curcumin-loaded biodegradable nanoparticles were obtained by the miniemulsification/evaporation technique.•An UV–Vis method to quantify the actual amount of curcumin entrapped in the nanoparticles was validated.•Curcumin concentration from 4 to 40mgL−1 can be safely determined by the validated UV–Vis method.•The curcumin-loaded nanoparticles were characterized in respect of morphology and curcumin concentration. Curcumin is a natural yellow-orange pigment extracted from turmeric and is a potential substitute of health-dangerous artificial dyes. Nanoencapsulation in biodegradable polymers is a promising alternative to improve curcumin stability and water solubility but curcumin concentration inside the nanoparticles must be precisely known. A reliable method to determine the actual curcumin concentration must be validated since the validation procedures warrant that the method is adequate and sufficient for the specific application involved. This work describes the validation parameters given by the International Conference on Harmonisation (ICH) guidelines to adopt an analytical method based on Ultraviolet–visible spectroscopy for the quantitative determination of curcumin encapsulated in poly(l-lactic acid) nanoparticles. This method was validated in respect to linearity, detection limit, quantification limit, accuracy and precision. Studies on the analytical procedure validation warranted safety in final results obtained for the curcumin concentration in the nanoparticles.