A: Proceed as directed for Identification A under American Ginseng, using the following Test solution.

B: The retention times of the peaks for ginsenosides Rg1, Re, Rb1, Rb2, Rc2, and Rd in the chromatogram of the Test solution correspond to those in the chromatogram of Standard solution 1, as obtained in the test for Content of ginsenosides under American Ginseng. The ratio of the peak reaponse for Rb2 to the peak response for Rb1 is less than 0.4; and the ratio of the peak response for Rg1 to the peak response for Rb1 is less than 0.3. The chromatogram shows no significant peak at the retention time corresponding to that of the RF for ginsenoside in the chromatogram of Standard solution 2, as obtained in the test for Content of ginsenosides under American Ginseng.

Mobile phase and Chromatographic system— Proceed as directed for the Content of ginsenosides under American Ginseng.

Standard solution— Prepare a solution of USP Powdered American Ginseng Extract RS in a mixture of water and alcohol (6:4) having a known concentration of about 1 mg of Rb1 per mL.

Test solution— Accurately weigh not fewer than 20 Tablets, and reduce to a very fine powder. To a conical flask, transfer an accurately weighed portion of the powder expected to contain an amount of Extract equivalent to about 15 mg of total ginsenosides. Add 15 mL of methanol, and shake to mix. Sonicate the mixture at 25 to 30 for 30 minutes. Cool, pass through filter paper, and return the residue to the conical flask. Add another 15 mL of methanol, sonicate the mixture at 25 to 30 for 30 minutes, and filter. Wash the residue with three 15-mL portions of methanol. Evaporate the combined extracts and washings to dryness under vacuum at 45 to 50. Quantitatively transfer the residue to a 10.0-mL volumetric flask, using small volumes of methanol, and dilute with methanol to volume.

Procedure— Proceed as directed for Procedure in the test for Content of ginsenosides under American Ginseng. Separately calculate the quantity, in mg, of each relevant ginsenoside (Rg1, Re, Rb1, Rc, Rb2 , and Rd) in the portion of Tablets taken to prepare the Test solution by the formula: in which C is the concentration, in mg per mL, of USP Powdered American Ginseng Extract RS in the Standard solution; P is the labeled content of the corresponding ginsenoside in the USP Powdered American Ginseng Extract RS; and rU and rS are the peak responses of the relevant ginsenosides obtained from the Test solution and the Standard solution, respectively. Calculate the content of ginsenosides as the sum of the individual quantities of Rg1, Re, Rb1, Rc, Rb2, and Rd.

(Official January 1, 2007)