Simultaneous Determination of Fangchinoline and Tetrandrine in Qi-Fang-Xi-Bi-Granules by RP-HPLC.

Knee Osteoarthritis is one of the most common diseases of elder worldwide. Qi-Fang-Xi-Bi-Granules (QFXBG) is a new Chinese medicine granules employed for the treatment of Knee Osteoarthritis. Fangchinoline (FAN) and tetrandrine (TET) are used as targets of quality control of QFXBG. A simple, practical high-performance liquid chromatographic method was developed for the simultaneous quantitation of FAN and TET in Stephaniae tetrandrae radix and QFXBG. The analysis was performed on a Athena C18 column (250 × 4.6 mm, 5 µm) with mobile phase of methanol-water (65 : 35, v/v, pH 3.0, adjusted by glacial acetic acid) containing 1.0 g/L sodium 1-octanesulfonate. This method was validated in terms of linearity, precision, accuracy and recovery. Results showed that this method had good linearity with R(2) at >0.999. The limit of detection and limit of quantification for FAN were 0.13 and 0.35 mg/L, while for TET were 0.28 and 0.76 mg/L, respectively. The relative standard deviations of precision were 0.1-1.3% for intraday and 0.5-2.4% for interday. The recovery was 94.56-98.81% of FAN and 94.07-99.12% of TET, respectively. The chromatographic analytical time was 14 min. This method was successfully applied for the quantitative analysis of FAN and TET in Stephaniae tetrandrae radix and QFXBG, so that it could be extended to quality control of QFXGB in commercial.