Medium: dilute hydrochloric acid (1in 100)containing 0.02%of sodium lauryl sulfate;900mL.

Apparatus 1: 100rpm.

Time: 60minutes.

Procedure— Determine the amount of C22H28O3dissolved from UVabsorbances at the wavelength of maximum absorbance at about 248nm,measured from a baseline drawn from 350nm through 310nm and extending beyond the peak maximum,of filtered portions of the solution under test,suitably diluted with Dissolution Medium,in comparison with a Standard solution having a known concentration of USP Norethindrone Acetate RSin the same medium.[NOTE—The Standard solution may be prepared by dissolving the Reference Standard in a volume of methanol,not exceeding 0.5%of the final volume of the solution,and diluting quantitatively with Dissolution Medium.]

Tolerances— Not less than 70%(Q)of the labeled amount of C22H28O3is dissolved in 60minutes.

Procedure for content uniformity— Transfer 1finely powdered Tablet to a 100-mLvolumetric flask with the aid of about 75mLof alcohol.Heat the alcohol to boiling,and allow the mixture to remain at a temperature just below the boiling point for about 15minutes,with occasional swirling.Cool to room temperature,dilute with alcohol to volume,mix,and centrifuge a portion of the contents at about 2000rpm until the solution becomes clear.Dilute a portion of the supernatant quantitatively and stepwise with alcohol to obtain a solution containing approximately 10µg of norethindrone acetate per mL.Concomitantly determine the absorbances of this solution and of a Standard solution of USP Norethindrone Acetate RSin alcohol having a known concentration of about 10µg per mLin 1-cm cells at the wavelength of maximum absorbance at about 240nm,with a suitable spectrophotometer,using alcohol as the blank.Calculate the quantity,in mg,of C22H28O3in the Tablet taken by the formula: in which Tis the labeled quantity,in mg,of norethindrone acetate in the Tablet,Cis the concentration,in µg per mL,of USP Norethindrone Acetate RSin the Standard solution,Dis 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 AUand ASare the absorbances of the solution from the Tablet and the Standard solution,respectively.

2C(AU/AS),