Test solution (for soft-shell gelatin capsules)— Transfer a portion of the content of the Capsules, equivalent to about 100 mg of Extract, to a separatory funnel containing 30 mL of a solution consisting of a mixture of hexanes, methanol, and water (20:15:10), dissolve in this mixture, and collect the lower layer. Wash the upper layer with three 15-mL portions of a mixture of methanol and water (15:10), and combine the washings with the lower layer. Evaporate to dryness under vacuum at 45 to 50. Dissolve the residue in 5 mL of methanol.

Test solution (for hard-shell gelatin capsules)— Transfer a portion of the content of the Capsules, equivalent to about 100 mg of Extract, to a conical flask. Extract at 55 with three 20-mL portions of a mixture of water and methanol (8:2). Evaporate the combined extracts to dryness under vacuum at 45 to 50. Dissolve the residue in 5 mL of methanol.

Mobile phase and Chromatographic system— Proceed as directed in the test for Content of ginsenosides under Powdered Asian Ginseng Extract.

Standard solution— Transfer an accurately weighed quantity of USP Powdered American Ginseng Extract RS, and dilute quantitatively, and stepwise if necessary, with a mixture of water and alcohol (6:4) to obtain a solution having a known concentration of about 0.2 mg per mL of ginsenoside Rb1.

Test solution (for soft-gelatin capsules)— Using a suitable cutting instrument, open not fewer than 20 Capsules, and transfer the contents to a suitable container. Mix to homogenize, and transfer an accurately weighed portion, expected to contain an amount of Extract equivalent to 12 mg of ginsenosides, to a suitable flask with a stopper. Add 5.0 mL of tetrahydrofuran, and sonicate for 5 minutes. Add 25.0 mL of a mixture of water and methanol (60:40), and shake for 50 minutes in an automatic shaker. Transfer about 15.0 mL of the obtained emulsion to a centrifuge tube with a stopper, add about 800 mg of sodium chloride, shake for 30 seconds, and centrifuge to obtain a clear upper phase. Dilute 1.0 mL of the upper phase with 4 mL of water in a suitable tube, and transfer the solution to a column containing 360 mg of packing L2 that has been previously treated with 3.0 mL of methanol followed by 8.0 mL of water. [note—Elute slowly, not faster than 1 drop per second, in all elution steps. Do not use vacuum.] Rinse the tube with 5 mL of water, transfer to the column taking the precaution of slow elution, and discard the eluate. Repeat the elution with 5 mL of a mixture of water and methanol (60:40), and discard the eluate. Elute the ginsenosides with 5.0 mL of methanol. Evaporate the solution under a stream of nitrogen at 40 (about 50 minutes), and dissolve the residue with 1.0 mL of a solution of water and acetonitrile (8:2).

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 Capsules 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 percentage of the corresponding ginsenoside in the USP Powdered American Ginseng Extract RS; rU is the peak response for each relevant ginsenoside in the chromatogram of the Test solution; and rS is the peak response of the corresponding ginsenoside in the chromatogram of the Standard solution. Calculate the content of ginsenosides, in mg, as the sum of the individual quantities of each relevant ginsenoside (Rg1, Re, Rb1, Rc, Rb2, and Rd).

Mobile phase and Chromatographic system— Proceed as directed in the test for Content of ginsenosides under Powdered Asian Ginseng Extract.

Solvent A: upper phase of a mixture consisting of hexane, methanol, and water (4:3:2).

Solvent B: lower phase consisting of a mixture of hexane, methanol, and water (4:3:2).

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 1 (for soft-gelatin capsules)— Using a suitable cutting instrument, open not fewer than 20 Capsules, and transfer the contents to a suitable container. Mix to homogenize, and transfer an accurately weighed portion, expected to contain an amount of Extract equivalent to 15 mg of total ginsenosides, to a 50-mL flask. Add 10.0 mL of Solvent A, and sonicate for 3 to 5 minutes at 25 to 30. Transfer the solution to a 125-mL separator funnel. To the residue, add 10 mL of Solvent B, and sonicate for 3 to 5 minutes at 25 to 30. Transfer the solution to the same separator funnel. Repeat the above procedure twice (the total volume will be about 60 mL). Shake, and then allow the phases to separate. Collect the combined lower phase in a round-bottom flask, and wash the combined upper phase twice with 10 mL of Solvent B. Evaporate the combined lower phase to dryness under vacuum at 45 to 50. Quantitatively transfer the residue to a 10-mL volumetric flask using small volumes of methanol, and dilute with methanol to volume.

Test solution 2 (for hard-gelatin capsules)— Accurately weigh the contents of not fewer than 20 Capsules, and composite the contents. Transfer an accurately weighed portion of the composite, expected to contain an amount of Extract equivalent to approximately 15 mg of total ginsenosides, to a conical flask. 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 washing to dryness under vacuum at 45 to 50. Quantitatively transfer the residue to a 10-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 Capsules taken to prepare Test solution 1 or Test solution 2 by the formula: in which C is the concentration, in mg per mL, of USP Powdered American Ginseng Extract RS in the Standard solution; and the other terms are as defined for Method 1. Calculate the content of ginsenosides, in mg, as the sum of the individual quantities of each relevant ginsenoside (Rg1, Re, Rb1, Rc, Rb2, and Rd).