Identification—
Shake the contents of a sufficient number of Capsules, equivalent to about 50 mg of Danazol, with 50 mL of chloroform, and filter. Evaporate the filtrate on a steam bath with the aid of a stream of nitrogen to dryness: the IR absorption spectrum of a potassium bromide dispersion of the residue, previously dried, exhibits maxima at the same wavelengths as that of a similar preparation of
USP Danazol RS.
Dissolution 
711
—
Medium:
0.75% sodium lauryl sulfate solution; 900 mL.
Apparatus 2:
75 rpm.
Time:
30 minutes.
Procedure—
Determine the amount of C
22H
27NO
2 dissolved as follows. Remove an aliquot from the solution under test at a point midway between the stirring shaft and the wall of the vessel and approximately midway in depth. Measure the amount in solution in filtered portions of the
Dissolution Medium, suitably diluted with the
Dissolution Medium, at the wavelength of maximum absorbance at about 286 nm, with a suitable spectrophotometer, in comparison with a solution of known concentration of
USP Danazol RS prepared as follows. Transfer 10 mg of
USP Danazol RS, accurately weighed, to a 10-mL volumetric flask, and dissolve in isopropyl alcohol. Transfer 2.0 mL to a 100-mL volumetric flask, dilute with
Dissolution Medium to volume, and mix.
Tolerances—
Not less than 75% (Q) of the labeled amount of C22H27NO2 is dissolved in 30 minutes.
Assay—
Mobile phase—
Prepare a filtered and degassed mixture of acetonitrile, methanol, and water (4:3:3). Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Standard preparation—
Dissolve an accurately weighed quantity of
USP Danazol RS in
Mobile phase to obtain a solution having a known concentration of about 0.2 mg per mL.
Assay preparation—
Accurately weigh the contents of not less than 20 Capsules. Mix the contents, and transfer an accurately weighed portion of the powder, equivalent to about 100 mg of danazol, to a 100-mL volumetric flask. Add about 50 mL of Mobile phase, and shake by mechanical means for about 10 minutes. Dilute with Mobile phase to volume, mix, and filter, discarding the first 5 mL of the filtrate. Pipet 5 mL of the filtrate into a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix. Filter a portion of this solution through a 0.45-µm porosity filter, discarding the first 5 mL of the filtrate.
Chromatographic system
(see
System Suitability under
Chromatography 621)—The liquid chromatograph is equipped with a 270-nm detector and a 3.9-mm × 15-cm column that contains 4-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the
Standard preparation, and record the peak responses as directed under
Procedure: the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of danazol in the portion of Capsules taken by the formula:
500C(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Danazol RS in the
Standard preparation, and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
