Packaging and storage—
Preserve in tight, light-resistant containers.
USP Reference standards 
11
—
USP Perphenazine RS.
NOTE—Throughout the following procedures, protect test or assay specimens, the USP Reference Standard, and solutions containing them, by conducting the procedures without delay, under subdued light, or using low-actinic glassware.
Identification—
Shake a portion of finely powdered Tablets, equivalent to about 5 mg of perphenazine, with about 10 mL of chloroform, filter, evaporate the filtrate on a steam bath nearly to dryness, and dissolve the residue in 5 mL of methanol: the solution so obtained responds to the
Identification test under
Perphenazine Injection.
Dissolution 711—
Medium:
0.1 N hydrochloric acid; 900 mL.
Apparatus 2:
50 rpm.
Time:
45 minutes.
Procedure—
Determine the amount of C
21H
26ClN
3OS dissolved from UV absorbances at the wavelength of maximum absorbance at about 257 nm of filtered portions of the solution under test, suitably diluted with
Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of
USP Perphenazine RS in the same medium.
Tolerances—
Not less than 75% (Q) of the labeled amount of C21H26ClN3OS is dissolved in 45 minutes.
Assay—
Assay preparation—
Weigh and finely powder not less than 20 Tablets. Transfer a portion of the powder, equivalent to about 4 mg of perphenazine, to a glass-stoppered conical flask, pipet into the flask 25 mL of Acid-alcohol solution, shake by mechanical means for 30 minutes, and centrifuge a portion of the mixture. The clear supernatant fluid is the Assay preparation.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Perphenazine Injection. Calculate the quantity, in mg, of C
21H
26ClN
3OS in the portion of Tablets taken by the formula:
0.025C(AU / AS),
in which
C is the concentration, in µg per mL, of
USP Perphenazine RS in the
Standard preparation, and
AU and
AS are the absorbances of the solutions from the
Assay preparation and the
Standard preparation, respectively.
