Identification—
Shake the contents of a sufficient number of Capsules,equivalent to about 50mg of Danazol,with 50mLof chloroform,and filter.Evaporate the filtrate on a steam bath with the aid of a stream of nitrogen to dryness:the IRabsorption 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 á711ñ—
Medium:
0.75%sodium lauryl sulfate solution;900mL.
Apparatus 2:
75rpm.
Time:
30minutes.
Procedure—
Determine the amount of C
22H
27NO
2dissolved 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 286nm,with a suitable spectrophotometer,in comparison with a solution of known concentration of
USP Danazol RSprepared as follows.Transfer 10mg of
USP Danazol RS,accurately weighed,to a 10-mLvolumetric flask,and dissolve in isopropyl alcohol.Transfer 2.0mLto a 100-mLvolumetric flask,dilute with
Dissolution Mediumto volume,and mix.
Tolerances—
Not less than 75%(Q)of the labeled amount of C22H27NO2is dissolved in 30minutes.
Assay—
Mobile phase—
Prepare a filtered and degassed mixture of acetonitrile,methanol,and water (4:3:3).Make adjustments if necessary (see
System Suitabilityunder
Chromatography á621ñ).
Standard preparation—
Dissolve an accurately weighed quantity of
USP Danazol RSin
Mobile phaseto obtain a solution having a known concentration of about 0.2mg per mL.
Assay preparation—
Accurately weigh the contents of not less than 20Capsules.Mix the contents,and transfer an accurately weighed portion of the powder,equivalent to about 100mg of danazol,to a 100-mLvolumetric flask.Add about 50mLof Mobile phase,and shake by mechanical means for about 10minutes.Dilute with Mobile phaseto volume,mix,and filter,discarding the first 5mLof the filtrate.Pipet 5mLof the filtrate into a 25-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Filter a portion of this solution through a 0.45-µm porosity filter,discarding the first 5mLof the filtrate.
Chromatographic system
(see
System Suitabilityunder
Chromatography á621ñ)—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 1.5mLper 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 20µL)of the
Standard preparationand the
Assay preparationinto 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
Cis the concentration,in mg per mL,of
USP Danazol RSin the
Standard preparation,and
rUand
rSare the peak responses obtained from the
Assay preparationand the
Standard preparation,respectively.