[Optimization of method for determination of Forsythia Fructus and discussion on the establishment of quality control standard for green (old) Forsythia Fructus]

In order to obtain the optimum method for content determination of Forsythia Fructus (FF), a variety methods for the sample preparation of FF were evaluated by the content determination methods of Chinese Pharmacopoeia. And an optimum method was screened and as follows: 30 times with 70% ethanol solution in ultrasonic extractor for half an hour. The method can achieve the best effect of simultaneously extracting forsythoside A and forsythin. Then, a HPLC method for simultaneous determination of forsythoside A and forsythin was established by methodology. The HPLC chromatographic conditions: the mobile phase consisted of acetonitrile (A)-0.4% acetic acid solution (B) with gradient elution [0-33 min，15%A，33-43 min，15%-25%A，43-60 min，25% A] was at the flow rate of 1 mL·min⁻¹, the column temperature was 25 °C, and the detection wavelength was 330 and 277 nm. Moreover, the contents of forsythoside A and forsythin for 10 Green Forsythia Fructus (GF) and 5 Old Forsythia Fructus (OF) were determined by this method and Chinese Pharmacopoeia. The result not only displayed that the established method is effective, rapid, and simple, but also showed that the contents of forsythoside A and forsythin for GF and OF were significantly different. Which implied that the forsythoside A and forsythin limit standard for GF and OF should be controled by different values. This studies provide an important basis for the establishment of the content determination of FF and the quality control standard for GF and OF.