Medium: 1% sodium lauryl sulfate; 900 mL.

Apparatus 2: 75 rpm.

Time: 60 minutes.

Procedure— Determine the amount of C24H32O4 dissolved from UV absorbances at the wavelength of maximum absorbance at about 292 nm of filtered portions of the solution under test, suitably diluted with 1% sodium lauryl sulfate, if necessary, in comparison with a Standard solution having a known concentration of USP Megestrol Acetate RS in the same Medium.

Tolerances— Not less than 75% (Q) of the labeled amount of C24H32O4 is dissolved in 60 minutes.

Procedure for content uniformity— Place 1 Tablet in a volumetric flask of suitable size so that the final expected solution concentration is between about 0.2 and 1.0 mg of megestrol acetate per mL. Add 1 mL of water, and gently shake until the Tablet has disintegrated. Fill the flask to three-quarters of its nominal capacity with methanol, and shake by mechanical means for 20 minutes. Dilute with methanol to volume, mix, and filter, discarding the first 15 mL of the filtrate. Dilute 5.0 mL of the subsequent filtrate quantitatively with methanol to obtain a solution containing about 10 µg of megestrol acetate per mL. Prepare a Standard solution of USP Megestrol Acetate RS in the same medium having a known concentration of about 10 µg per mL. Record the absorbances of the solutions in 1-cm cells, against a blank of methanol, scanning from 350 nm to 260 nm. Measure the absorbances at the wavelength of maximum absorbance at about 288 nm. Calculate the quantity, in mg, of C24H32O4 in the Tablet taken by the formula: in which T is the labeled quantity, in mg, of megestrol acetate in the Tablet; C is the concentration, in µg per mL of USP Megestrol Acetate RS in the Standard solution; D is the concentration, in µg per mL, of the solution from the Tablet, based upon the labeled quantity per Tablet and the extent of dilution; and AU and AS are the absorbances of the solution from the Tablet and the Standard solution, respectively.

(Official January 1, 2007)

Mobile phase, Solvent mixture, Internal standard solution, Standard preparation, and Chromatographic system— Prepare as directed in the Assay under Megestrol Acetate.

Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 80 mg of megestrol acetate, to a 100-mL volumetric flask. Add about 10 mL of water, and shake for 10 minutes. Add 75 mL of acetonitrile, and shake for 30 minutes, then dilute with acetonitrile to volume, and mix. Place a 25-mL aliquot in a glass-stoppered, 35-mL centrifuge tube, insert the stopper, and centrifuge for 10 minutes. Transfer 5.0 mL of the supernatant and 5.0 mL of Internal standard solution to a 50-mL volumetric flask, dilute with Solvent mixture to volume, and mix.

Procedure— Proceed as directed for Procedure in the Assay under Megestrol Acetate. Calculate the quantity, in mg, of megestrol acetate (C24H32O4) in the portion of Tablets taken by the formula: in which the terms are as defined therein.