A: The retention times of the peaks for campesterol, stigmasterol, and -sitosterol, in the chromatogram of the Test solution, correspond to those in the chromatograms of the Standard solution, as obtained in the Content of sterols.

B: The retention time of the peak for docosyl ferulate in the chromatogram of the Test solution corresponds to that in the chromatogram of the Standard solution, as obtained in the Content of docosyl ferulate.

RUPTURE TEST— [NOTE—See Dissolution 711 for Apparatus.]

Derivatizing solution, Internal standard solution, System suitability solution, Standard stock solution, Standard solution, and Chromatographic system— Proceed as directed in Pygeum Extract.

Test solution— Transfer an accurately weighed quantity of Capsules, equivalent to about 100 mg of the labeled amount of Extract, into a 100-mL, round-bottomed flask. Add 2.0 mL of Internal standard solution and 20 mL of diluted hydrochloric acid. Attach a condenser, and reflux in a bath at 100 for 30 minutes. Cool the solution to room temperature, and adjust by the addition of about 5 mL of 10 N sodium hydroxide to a pH of 8. Extract twice using 50 mL of ether each time, wash the collected organic phases with 50 mL of water, and evaporate the organic phase to dryness under vacuum. Dissolve the residue with 4 mL of chloroform, and transfer to a cartridge containing 500 mg of packing L8 that has been conditioned with a 2-column volume of n-hexane. [NOTE—A suitable cartridge is Chromabond NH2, manufactured by Macheray Nagel, or equivalent.] Collect the eluate. Elute twice with a 1-column volume of a mixture of chloroform and isopropanol (2:1). Combine the eluates, and evaporate to dryness. Dissolve the residue in 10 mL of chloroform. Evaporate about 500 µL of this solution to dryness under a stream of nitrogen. Dissolve the residue with 80 µL of Derivatizing solution and 20 µL of pyridine. Allow to stand for not less than 10 minutes at room temperature.

Procedure— Proceed as directed in Pygeum Extract. Separately calculate the content, in mg, of campesterol, stigmasterol, and -sitosterol, respectively, in the portion of Capsules taken by the formula: in which C is the concentration of -sitosterol, in mg per mL, in the Standard solution; RU is the ratio of the appropriate sterol peak to the internal standard in the chromatogram of the Test solution; and RS is the ratio of the -sitosterol peak to the 5-cholestane internal standard in the chromatogram of the Standard solution. Calculate the total content of sterols, in mg, by adding the individual contents.

Solution A, Solution B, Mobile phase, and Chromatographic system— Proceed as directed for the Content of docosyl ferulate in Pygeum Extract.

Standard solution— Dissolve an accurately weighed quantity of USP Docosyl Ferulate RS with chloroform, and dilute quantitatively, and stepwise if necessary, with acetonitrile to obtain a solution having a known concentration of about 0.01 mg per mL. Filter with a 0.45-µm membrane or finer porosity.

Test solution— Accurately weigh the contents of not fewer than 20 Capsules, and transfer an accurately weighed quantity of the material, equivalent to 0.2 mg of the labeled amount of docosyl ferulate, to a 50-mL beaker. Add 5 mL of chloroform, and dissolve in an ultrasonic bath. Transfer to a 20-mL volumetric flask with the aid of not more than 2 mL of chloroform. Dilute with acetonitrile to volume, and mix. Filter through a 0.45-µm membrane or finer porosity.

Procedure— Proceed as directed for Procedure in Content of docosyl ferulate under Pygeum Extract, except to inject about 30 µL into the chromatograph. Calculate the content of docosyl ferulate, in mg, in the portion of Capsules taken by the formula: in which the terms are as defined therein.

(Official January 1, 2007)