Development of chromatographic methods for determination of agrimoniin and related polyphenols in pharmaceutical products.

Thin-layer chromatography (TLC) and liquid chromatography (LC) methods were developed for the qualitative and quantitative determination of agrimoniin, pedunculagin, ellagic acid, gallic acid, and catechin in selected herbal medicinal products from Rosaceae: Anserinae herba, Tormentillae rhizoma, Alchemillae herba, Agrimoniae herba, and Fragariae folium. Unmodified silica gel (TLC Si60, HPTLC LiChrospher Si60) and silica gel chemically modified with octadecyl or aminopropyl groups (HPTLC RP18W and HPTLC NH2) were used for TLC. The best resolution and selectivity were achieved with the following mobile phases: diisopropyl ether-acetone-formic acid-water (40 + 30 + 20 + 10, v/v/v/v), tetrahydrofuran-acetonitrile-water (30 + 10 + 60, v/v/v), and acetone-formic acid (60 + 40, v/v). Concentrations of the studied herbal drugs were determined by using a Chromolith Performance RP-18e column with acetonitrile-water-formic acid as the mobile phase. Determinations of linearity, range, detection and quantitation limits, accuracy, precision, and robustness showed that the HPLC method was sufficiently precise for estimation of the tannins and related polyphenols mentioned above. Investigations of suitable solvent selection, sample extraction procedure, and short-time stability of analytes at storage temperatures of 4 and 20 degrees C were also performed. The percentage of agrimoniin in pharmaceutical products was between 0.57 and 3.23%.