Procedure for content uniformity
Transfer 1 finely powdered Tablet to a 100-mL volumetric flask with the aid of about 75 mL of methanol. Heat the methanol to boiling, and allow to remain at a temperature just below the boiling point for 15 minutes with occasional swirling. Cool to room temperature, dilute with methanol to volume, and mix. Centrifuge a portion of the mixture at about 2000 rpm until the solution becomes clear. Transfer a portion of the supernatant, equivalent to about 1 mg of oxymetholone, to a 100-mL volumetric flask. Add 10 mL of a 1 in 250 solution of sodium hydroxide in methanol, and dilute with methanol to volume. Without delay, concomitantly determine the absorbances of this solution and a freshly prepared Standard solution of
USP Oxymetholone RS in the same medium having a known concentration of about 10 µg per mL in 1-cm cells at the wavelength of maximum absorbance at about 315 nm, with a suitable spectrophotometer, using a 1 in 2500 solution of sodium hydroxide in methanol as the blank. Calculate the quantity, in mg, of C
21H
32O
3 in the Tablet taken by the formula:
(TC / D)(AU / AS),
in which
T is the labeled quantity, in mg, of oxymetholone in the Tablet,
C is the concentration, in µg per mL, of
USP Oxymetholone RS in the Standard solution,
D is the concentration, in µg per mL, of oxymetholone in 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.