procedure for content uniformity—

Mobile phase and System suitability solution— Proceed as directed in the Assay.

Standard solution— Dissolve an accurately weighed quantity of USP Bicalutamide RS in tetrahydrofuran to obtain a solution having a known concentration of about 0.2 mg per mL. Transfer 5.0 mL of this solution to a 50–mL volumetric flask, and dilute with Mobile phase to volume.

Test solution— Transfer an accurately weighed quantity of the powdered Tablet prepared in the Assay preparation, equivalent to about 50 mg of bicalutamide, to a 25-mL volumetric flask. Add about 2 mL of tetrahydrofuran, and allow to stand for 5 minutes. Add about 20 mL of Mobile phase, and sonicate for 10 minutes. Allow to cool to room temperature, and dilute with Mobile phase to volume. Pass the sample through a suitable 0.2-µm filter.

Chromatographic system (see Chromatography 621)— Proceed as directed in the Assay, except to use a liquid chromatograph equipped with a 220-nm detector.

Procedure— Separately inject equal volumes (about 10 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of 4-amino-2-(trifluoromethyl)benzonitrile in the portion of Tablets taken by the formula: in which 1.4 is the relative response factor for 4-amino-2-(trifluoromethyl)benzonitrile, CS is the concentration, in mg per mL, of USP Bicalutamide RS in the Standard solution; CU is the concentration, in mg per mL, of bicalutamide in the Test solution based on the label claim; rU is the peak area for 4-amino-2-(trifluoromethyl)benzonitrile obtained from the Test solution; and rS is the peak area for bicalutamide obtained from the Standard solution: not more than 0.1% of 4-amino-2-(trifluoromethyl)benzonitrile is found. [note—The relative retention time for 4-amino-2-(trifluoromethyl)benzonitrile is about 0.4.]

Mobile phase— Prepare a mixture of water, tetrahydrofuran, and acetonitrile (65:20:15).

Standard preparation— Dissolve an accurately weighed quantity of USP Bicalutamide RS in tetrahydrofuran to obtain a solution having a known concentration of about 0.8 mg per mL. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, and dilute with Mobile phase to volume.

Assay preparation— Grind not fewer than 20 Tablets to a fine powder. Transfer an accurately weighed quantity of powdered Tablets, equivalent to about 50 mg of bicalutamide, to a 100-mL volumetric flask. Add about 50 mL of tetrahydrofuran, and sonicate for at least 10 minutes to complete dissolution. Allow to cool to room temperature, and dilute with tetrahydrofuran to volume. Pass this solution through a suitable 0.45-µm filter. Transfer 4.0 mL of the filtrate to a 50-mL volumetric flask, and dilute with Mobile phase to volume.

System suitability solution— Dissolve suitable quantities of USP Bicalutamide RS and USP Bicalutamide Related Compound B RS in tetrahydrofuran to obtain a solution having known concentrations of about 0.8 mg of USP Bicalutamide RS per mL and 0.4 mg of USP Bicalutamide Related Compound B RS per mL. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, and dilute with Mobile phase to volume.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 270-nm detector, and a 5-mm × 12.5-cm column that contains 3-µm packing L1. The flow rate is about 1.5 mL per minute. The column temperature is maintained at 50. Chromatograph the System suitability solution, and record the peak areas as directed for Procedure: the relative retention time for the bicalutamide related compound B peak is about 1.1; the resolution, R, between bicalutamide and bicalutamide related compound B is greater than 1.9; the tailing factor of the bicalutamide peak is less than 1.3; and the relative standard deviation for replicate injections calculated for the bicalutamide peak is not more than 2.0%.

Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the areas for the bicalutamide peaks. Calculate the quantity, in percentage of the label claim, of bicalutamide (C18H14F4N2O4S) in the portion of Tablets taken by the formula: in which CS is the concentration, in mg per mL, of USP Bicalutamide RS in the Standard preparation; CU is the concentration, in mg per mL, of bicalutamide in the Assay preparation based on the label claim; and rU and rS are the peak areas obtained from the Assay preparation and the Standard preparation, respectively.USP32