A: Infrared Absorption á197Mñ.

B: Ultraviolet Absorption á197Uñ—

Solution: 10µg per mL.

Medium: methanol.

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

Standard solution— Dissolve an accurately weighed quantity of USPm-Aminoglutethimide RSin Diluentto obtain a solution having a known concentration of about 1mg per mL.Dilute an accurately measured volume of this solution quantitatively,and stepwise if necessary,with Diluentto obtain a solution having a known concentration of about 10µg per mL.

Test solution— Transfer about 100mg of Aminoglutethimide,accurately weighed,to a 100-mLvolumetric flask,and dissolve in Diluent.Dilute with Diluentto volume,mix,and pass through a 0.45-µm or finer porosity filter,discarding the first 5mLof the filtrate.

Procedure— Separately inject equal volumes (about 10µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the areas for all of the peaks.The relative retention times are about 0.8for aminoglutethimide and 1.0for m-aminoglutethimide.Calculate the percentage of m-aminoglutethimide in the specimen of Aminoglutethimide taken by the formula: in which Cis the concentration,in µg per mL,of USPm-Aminoglutethimide RSin the Standard preparation;Wis the weight,in mg,of the specimen taken;and rUand rSare the m-aminoglutethimide peak responses obtained from the Test preparationand the Standard preparation,respectively:not more than 2.0%of m-aminoglutethimide is found.Calculate the percentage of each peak,other than the main peak and the m-aminoglutethimide peak,if present,by the same formula: in which riis the response of each peak,and rtis the sum of the responses of all the peaks in the chromatogram obtained from the Test preparation:not more than 1.0%total impurities,other than m-aminoglutethimide,is found.

Acetate buffer— Mix 150mLof 0.1Nacetic acid with 50mLof 0.1Npotassium hydroxide,dilute with water to 1000mL,and mix.

Mobile phase— Dissolve 100mg of edetate disodium in 350mLof Acetate buffer,add 650mLof methanol,mix,and cool to room temperature.Adjust with glacial acetic acid to a pHof 5.0±0.1,filter,and degas.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Standard solution— Dissolve an accurately weighed quantity of USP Azo-aminoglutethimide RSin dimethyl sulfoxide,and dilute quantitatively,and stepwise if necessary,with dimethyl sulfoxide to obtain a solution having a known concentration of about 0.5µg per mL.

Test solution— Transfer about 100mg of Aminoglutethimide,accurately weighed,to a 100-mLvolumetric flask.Dissolve in and dilute with dimethyl sulfoxide to volume,and mix.

Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 328-nm detector and a 3.9-mm ×15-cm column that contains packing L1.The flow rate is about 1mLper minute.Chromatograph the Standard solution,and record the peak responses as directed for Procedure:the capacity factor for the analyte peak is between 2.0and 5.0,the column efficiency determined from the analyte peak is not less than 800theoretical plates,and the tailing factor for the analyte peak is not more than 1.2.

Procedure— Separately inject equal volumes (about 10µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the areas for the major peaks.[NOTE—The aminoglutethimide elutes with the dimethyl sulfoxide.]Calculate the percentage of azo-aminoglutethimide in the specimen of Aminoglutethimide taken by the formula: in which Cis the concentration,in µg per mL,of USP Azo-aminoglutethimide RSin the Standard solution;Wis the weight,in mg,of the specimen taken;and rUand rSare the azo-aminoglutethimide peak responses obtained from the Test solutionand the Standard solution,respectively:not more than 0.03%of 3,3¢-(azodi-4,1-phenylene)-3,3¢-dimethylbis-[2,6-piperidinedione],corresponding to azo-aminoglutethimide,is found.

Solvent— Use dimethyl sulfoxide.

Acetate buffer— Add 240mLof 0.1Nacetic acid to 200mLof 0.1Npotassium hydroxide in a 2000-mLvolumetric flask,add about 500mLof water,and mix.Adjust by the addition of either 1Nacetic acid or 1Npotassium hydroxide to a pHof 5.0±0.1.Dilute with water to volume,and mix.

Mobile phase— Prepare a filtered and degassed mixture of Acetate bufferand methanol (73:27).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Diluent— Prepare a mixture of Acetate bufferand methanol (1:1).

Standard preparation— Dissolve an accurately weighed quantity of USP Aminoglutethimide RSin Diluentto obtain a solution having a known concentration of about 0.5mg per mL.

Assay preparation— Transfer about 50mg of Aminoglutethimide,accurately weighed,to a 100-mLvolumetric flask,and dissolve in Diluent.Dilute with Diluentto volume,mix,and pass through a 0.45-µm or finer porosity filter,discarding the first 5mLof the filtrate.

Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 240-nm detector and a 3.9-mm ×15-cm column that contains 4-µm packing L1.The column temperature is maintained at about 40,and the flow rate is about 1.3mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the tailing factor for the analyte peak is not more than 1.7,and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— [NOTE—Use peak areas where peak responses are indicated.]Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C13H16N2O2in the portion of Aminoglutethimide taken by the formula: in which Cis the concentration,in mg per mL,of USP Aminoglutethimide RSin the Standard preparation;and rUand rSare the aminoglutethimide peak responses obtained from the Assay preparationand the Standard preparation,respectively.