Analysis of swertiamarin in Swertia herb and preparations containing this crude drug by capillary electrophoresis.

Swertia herb (florescent whole plantof Swertia japonica, Gentianaceae) has long been utilized as a folk medicine in Japan. It is often blended in general gastroenteric drugs as a bitter stomachic. Swertiamarin, a bitter secoiridoid glycoside, is the representative constituent of this crude drug and Swertia herb is normally evaluated by the swertiamarin content. To date, papers have described the discrimination of Swertia herbs from other bitter crude drugs, estimation of swertiamarin and seasonal variation in swertiamarin content using thin-layer chromatography, while other papers have reported quantitative determination of swertiamarin using high-performance liquid chromatography (HPLC). In our previous papers, we reported analyses of the constituents of some crude drugs using capillary electrophoresis (CE). To aid in the evaluation of crude drugs, we succeeded in our attempt to separate and determine the quantity of swertiamarin in Swertia herb. Subsequently, we applied the same analytical condition to estimate the swertiamarin contents in Japanese pharmacopoeia stomachic preparations, in OTC gastroenteric drugs and in OTC hair tonics containing Swertia herb.