Asian Journal
Of Traditional Medicines

Abstract: The purpose of this study was to develop a sensitive and fast microdialysis method coupled with high-performance liquid chromatography (HPLC) for determination of gallic acid in freely moving rats after i.g. administration of an aqueous extract of crude Fructus corni and the processed products of jiuzheng pin (JZP). After application, the dialysates were automatically sampled using a microfraction collector from the left jugular vein and measured by high performance liquid chromatography (HPLC) with a diode array detector (DAD). An Agilent Zorbax Extend C₁₈ column (250 × 4.6 mm i.d., 5 μm) was used as the analytical column and the temperature was maintained at 30 ºC. The mobile phase consisted of 2% acetonitrile and 98 % aqueous phosphoric acid (0.1 %, v/v). The wavelength of the detector was set at 218 nm. All calibration curves showed good linear regression (r² ≥ 0.9998) within the tested ranges. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.0438 mg/L and 0.0876 mg/L, respectively. The mean recoveries were 97.86 %, 97.48 %, 96.49 %, for high, middle, and low concentrations of the samples, respectively. In conclusion, this method is proved to be rapid, accurate and simple. Real-time in vivo monitoring of the concentration of gallic acid provides a basis for further investigation of the mechanism of action of Fructus corni.

Key words: Fructus corni, gallic acid, microdialysis, HPLC-DAD