Test specimen— Transfer 500 mg of finely powdered Tablets to a suitable container, add 25 mL of acetone, mix, and filter. Evaporate the filtrate at room temperature to dryness, and dry the residue in vacuum over silica gel for 2 hours.

Medium: dilute hydrochloric acid (7 in 1000); 1000 mL.

Apparatus 1: 100 rpm.

Time: 30 minutes.

Procedure— Determine the amount of C13H16N2O2 dissolved from UV absorbances at the wavelength of maximum absorbance at about 237 nm on filtered portions of the solution under test, suitably diluted with pH 7.5 phosphate buffer, in comparison with a Standard solution having a known concentration of USP Aminoglutethimide RS in the same Medium.

Tolerances— Not less than 70% (Q) of the labeled amount of C13H16N2O2 is dissolved in 30 minutes.

Acetate buffer, Mobile phase, Diluent, and Chromatographic system— Prepare as directed in the Assay under Aminoglutethimide.

m-Aminoglutethimide solution— Prepare as directed for the Standard solution in the test for Chromatographic purity and limit of m-aminoglutethimide under Aminoglutethimide.

Test solution— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 200 mg of aminoglutethimide, to a 200-mL volumetric flask. Add about 130 mL of Diluent, and sonicate for 5 minutes. Shake by mechanical means for 30 minutes, dilute with Diluent to volume, mix, and pass through a 0.45-µm or finer porosity filter, discarding the first 5 mL of the filtrate.

Procedure— Separately inject about 10 µL of the m-Aminoglutethimide solution and the Test solution into the chromatograph, record the chromatograms, and measure the areas for all of the peaks in the chromatogram obtained from the Test solution. The relative retention times are about 0.8 for aminoglutethimide and 1.0 for m-aminoglutethimide. Calculate the percentage of each peak, other than the main peak and the m-aminoglutethimide peak, if present, by the same formula: in which ri is the response of each peak and rs is the sum of the responses of all of the peaks excluding that of the m-aminoglutethimide peak in the chromatogram obtained from the Test solution: not more than 2.0% total impurities, other than m-aminoglutethimide, is found.

Acetate buffer, Mobile phase, Diluent, Standard preparation, and Chromatographic system— Prepare as directed in the Assay under Aminoglutethimide.

Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 200 mg of aminoglutethimide, to a 200-mL volumetric flask. Add about 130 mL of Diluent, and sonicate for 5 minutes. Shake by mechanical means for 30 minutes, dilute with Diluent to volume, and mix. Centrifuge this solution, and transfer 25.0 mL of the clear supernatant to a 50-mL volumetric flask, dilute with Diluent to volume, mix, and pass through a 0.45-µm or finer porosity filter, discarding the first 5 mL of the filtrate.

Procedure— Proceed as directed for Procedure in the Assay under Aminoglutethimide. Calculate the quantity, in mg, of aminoglutethimide (C13H16N2O2) in the portion of Tablets taken by the formula: in which the terms are as defined therein.