Development and validation of an HPLC method for quality control of Pueraria lobata flower.

Pueraria lobata, also known as Kudzu (Japan) or Ge (China), is a medicinal plant widely used in Oriental traditional medicine. In this study the development, optimization and validation of an HPLC ethod for quality control of Pueraria flower plant material is presented. By means of this analytical method the three major compounds, i. e., the isoflavones tectorigenin 7- O-[beta- D-xylopyranosyl-(1 - 6)-beta- D-glucopyranoside], tectorigenin 7- O-beta- D-glucopyranoside and tectorigenin, were quantified, using the isoflavones genistin and genistein as external standards. The extraction procedure, the extraction solvent, the extraction yields and the HPLC conditions were evaluated and optimized. The samples were analyzed on an RP C18 column, and eluted with a binary system consisting of water and methanol using a linear gradient; detection was at 262 nm. Tectorigenin used in the recovery experiments was isolated and purified in the laboratory. The final method was fully validated according to the ICH guidelines in terms of linearity, precision and accuracy. The validation data showed that the precision, (RSD% (betweendays) of 3.1, 2.84 and 1.77 for the three major compounds, respectively), and the accuracy (recovery of 104.2 %) were acceptable. These validation results demonstrate the suitability of the method for the quality control of this crude drug.