Identification—
Finely powder a quantity of Tablets, equivalent to about 400 mg of sulfinpyrazone, boil with 20 mL of alcohol, and filter. Add water to the filtrate until the solution becomes turbid, allow to stand until crystals form (1 to 2 hours), remove the crystals by filtration, and dry at 105
for 1 hour: the sulfinpyrazone so obtained melts between 128
and 134
, and responds to the
Identification test under
Sulfinpyrazone.
Dissolution 
711
—
Apparatus 1:
100 rpm.
Time:
45 minutes.
Procedure—
Determine the amount of C
23H
20N
2O
3S dissolved from UV absorbances at the wavelength of maximum absorbance at about 259 nm 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 Sulfinpyrazone RS in the same
Medium.
Tolerances—
Not less than 75% (Q) of the labeled amount of C23H20N2O3S is dissolved in 45 minutes.
Assay—
Acetonitrile and tetrahydrofuran mixture
, Mobile phase, Internal standard solution, Standard preparation, Chromatographic system, and Procedure—Proceed as directed in the Assay for Sulfinpyrazone Capsules.
Assay preparation—
Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 100 mg of sulfinpyrazone, to a 200-mL volumetric flask, add 100 mL of acetonitrile, mix, add 10.0 mL of Internal standard solution, dilute with acetonitrile to volume, and mix. Filter, discarding the first 5 mL of the filtrate.
