The present work aimed to develop and validate spectrophotometric methods for simultaneous estimation of melatonin and quercetin in combined dosage form. Method is based on solving a simultaneous equation. Absorbance of melatonin and quercetin were measured at the respective absorbance maximum (λ max) at 276 and 372 nm. Methods are validated according to ICH guidelines. Linearity range for melatonin and quercetin is 2-10 μg/ml and 2-10 μg/ml at respective selected wavelengths. The coefficient of correlation for melatonin at 276 nm and quercetin at 372 nm is 0.997 and 0.993, respectively. A percentage estimation of melatonin and quercetin from the liposome is 99.5 % and 99.75 % respectively, with standard deviation less than 2. The proposed method was simple, rapid, and validated and can be used successfully for the routine simultaneous estimation of melatonin and quercetincombined liposome formulation.
Keywords : Melatonin, quercetin, UV spectroscopic method, Simultaneous equation method, Method Validation, ICH guidelines.