Determination of Ginsenosides (Ginseng Saponins) in Dry Root Powder from Panax ginseng, Panax quinquefolius, and Selected Commercial Products by Liquid Chromatography: Interlaboratory Study

Twelve collaborating laboratories assayed 4 products, namely, Panax ginseng, Panax quinquefolius, and 2 ginseng products, for 6 ginsenosides: Rb1, Rb2, Rc, Rd, Re, andRg1. Collaborators also received a negative control for the recovery study. Pure ginsenosides were provided as reference standards for the liquid chromatography (LC) analysis and the system suitability tests. The LC analyses were performed on the methanol extract using UV detection at 203 nm. For P. ginseng, individual ginsenosides were consistent in their means; repeatability standard deviations (RSDr)rangedfrom4.17to5.09% and reproducibility standard deviations (RSDR) ranged from 7.27 to 11.3%. For P. quinquefolius, the Rb1 and Rb2 ginsenosides were higher and lower in concentration than P. ginseng, with RSDr values of 3.44 and 6.60% and RSDR values of 5.91 and 12.6% respectively, and other analytes at intermediate precisions. For ginseng commercial products, RSDr values ranged from 3.39 to 8.12%, andRSDR values ranged from 7.65 to 16.5%. A recovery study was also conducted for 3 ginsenosides: Rg1, Re, andRb1. The average recoveries were 99.9, 96.2, and 92.3%, respectively. The method is not applicable for the determination of Rg1 and Re in ginseng product at levels <300 mg/kg.

Hemodialysis removal of norfloxacin

The effect of hemodialysis on norfloxacin removal was evaluated in 7 patients. Single 800-mg doses of the drug were given to the subjects prior to dialysis using cuprophan hollow fiber dialyzers. Arterial and venous sample pairs were obtained at hourly intervals during treatment. Norfloxacin plasma concentrations were determined by HPLC. The mean hemodialysis clearance and extraction ratio were 38.84 +/- 10.92 ml/min and 0.19 +/- 0.06, respectively. Small differences in these parameters were observed between dialyzers with different surface areas (p > 0.05) and also between treatments using different blood flow rates (p > 0.05). Since a relatively small amount of norfloxacin is removed by hemodialysis, dosage adjustment is not necessary to compensate for the extracorporeal removal.