RP-HPLC Method Development and Validation of Gallic acid in Polyherbal Tablet Formulation

A new simple, accurate, precise, sensitive and validated RP-HPLC method was developed for the estimation of Gallic acid in bulk and pharmaceutical tablet dosage form. The chromatographic conditions used for the separation was Phenomenex Luna C18 (2) (4.6 x 250mm, 5μ), rheodyne manual injector with capacity of 20µL and mobile phase comprised of Water: Acetonitrile (80: 20%v/v) and pH is maintained at 3.00 using Ophosphoric acid (OPA). The flow rate was 1.0mL/min with detection at 272nm. The retention time was found to be 3.60min. The linearity was found to be in the range of 0.5-50µg/mL for Gallic acid with correlation coefficient of 0.9994. The proposed method is accurate with 99.97% - 100.58 % recovery and precise (%RSD of repeatability, intra-day and inter-day variations were 1.26%, 0.48-0.95%, 0.80-1.83%). The Limit of Detection (LOD) and Limit of Quantification (LOQ) were found to be 0.0178µg/mL and 0.0539µg/mL respectively. The amount of Gallic acid in Polyherbal tablet was found to be 1.63%.