Simultaneous Determination of Pharmacological Active Phytocompound Gallic Acid and Quercetin in Aerial Parts of Solanun indicum and Solanum xanthocarpum by Validated High Performance Thin‑layer Chromatography (HPTLC) Method

Objective: Quantitative standardization of plant‑based products is challenging albeit essential to maintain their quality. This study aims to develop and validate high‑performance thin‑layer chromatography (HPTLC) method for the simultaneous determination of gallic acid and quercetin from aerial parts of Solanum indicum and Solanum xanthocarpum. Materials and Methods: The stock solution (1-mg/mL) of standard, gallic acid and quercetin in methanol: Water (1:1) was serially diluted and spotted (5 µL) on silica gel 60 F254 thin‑layer chromatography plates. Toluene: Ethyl acetate: Formic acid: Methanol (3.5:4.8:1.0.:0.7, v/v/v/v) was selected as mobile phase for analysis at 280 nm. Results: The developed method was robust and resolved gallic acid and quercetin at Rf0.34 ± 0.03 and 0.55 ± 0.01, respectively. The limit of detection (26 and 47 ng band-1 ) limit of quantification (78 and 141 ng.band-1 ), recovery (99.6–99.8 and 98.5–99.7%), and precision (≤1.98 and 1.97) were satisfactory for gallic acid and quercetin respectively. Linearity range for gallic acid and quercetin were 100–1000 (r 2 = 0.9993) and 150–900 ng band-1 (r 2 = 0.9956) and the contents estimated as 0.63 ± 0.01% and 0.57 ± 0.01% w/w in SI and 0.51 ± 0.01% and 0.69 ± 0.01% w/w for gallic acid and quercetin respectively. Conclusion: The developed HPTLC method was rapid, accurate, precise, reproducible, and specific for the concurrent estimation of gallic acid and quercetin. The method has been successfully applied in the analysis and routine quality control of herbal material and formulations containing Solanum Species.