Authors:Mhaveer Singh, Yunus Kamal, Ennus Tamboli, Rabea Parveen, Shahid Ansari and Sayeed Ahmad
A novel HPTLC method has been developed for the estimation of glabridin in Licorice rhizome and its Unani polyherbal formulation (Qurs-e-Gul). Separation was achieved on silica using toluene, dichloromethane, and ethyl acetate in equal ratios. A compact, well resolved peak of glabridin with RF value 0.56 ± 0.02 was observed. Calibration curve revealed a good linear relationship with r2 value of 0.993 between the peak area and concentration in the range of 25–500 ng spot−1. The proposed method was validated as per the International Conference on Harmonization (ICH) guidelines. The stability assessment was carried out by studying degradation of glabridin stressed by acid, base, oxidation, thermal, and humidity. Photodegradation was also carried out after keeping the drug in sunlight, dark, and in UV lights. The method proposed can be used for routine determination of glabridin in crude drugs and in herbal formulations containing Licorice as one of the ingredients, for quality control as well as for stability testing with high precision, accuracy and a wide range of linearity.
Authors:Prawez Alam, Y.T. Kamal, Mohammed H. Alqarni, Hala H. Zaatout and Maged S. Abdel-Kader
A new rapid, simple, economical, and environment-friendly reversed- phase high-performance thin-layer chromatography (RPHPTLC) method has been established for the simultaneous determination of glycyrrhizin and glabridin in Glycyrrhiza glabra roots, rhizomes and selected herbal formulations. The method was carried out using RP-18 silica gel 60 F254S HPTLC glass plates and methanol–water (7:3 v/v) as the mobile phase. The developed plates were scanned and quantified densitometrically at 256 and 233 nm for glycyrrhizin and glabridin, respectively. Glycyrrhizin and glabridin peaks from G. glabra roots and rhizomes and herbal formulations were identified by comparing their single spots at RF = 0.63 ± 0.02 and RF = 0.28 ± 0.01, respectively. Linear regression analysis revealed a good linear relationship between the peak areas and the amounts of glycyrrhizin and glabridin in the ranges of 1000–7000 and 100–700 ng band−1, respectively. The method was validated, in accordance with the International Conference on Harmonization (ICH) guidelines for precision, accuracy, and robustness. The proposed method will be useful to determine the therapeutic doses of glycyrrhizin and glabridin in herbal formulations as well as in bulk drug.
Aoki F, Nakagawa K, Kitano M, Ikematsu H, Nakamura K, Yokota S, Tominaga Y, Arai N, Mae T: Clinical safety of licorice flavonoid oil (LFO) and pharmacokinetics of glabridin in healthy humans. J. Am. Coll. Nutr. 26, 209–218 (2007