Identification
Dilute 1 mL with methanol to 5 mL. Apply 5 µL each of this solution and a solution of
USP Perphenazine RS in methanol containing 1 mg per mL to a suitable thin-layer chromatographic plate, coated with a 0.25-mm layer of chromatographic silica gel. Develop the chromatogram in a solvent system consisting of a mixture of acetone and ammonium hydroxide (200:1) until the solvent front has moved about 15 cm. Air-dry the plate, and spray lightly with a solution of iodoplatinic acid prepared by dissolving 100 mg of chloroplatinic acid in 1 mL of 1 N hydrochloric acid, adding 25 mL of potassium iodide solution (4 in 100), diluting with water to 100 mL, and adding 0.50 mL of formic acid: the
RF value of the principal spot obtained from the Injection corresponds to that obtained from the Standard solution.
Assay
Acid-alcohol solution
Transfer 10 mL of hydrochloric acid to a 1000-mL flask containing 500 mL of alcohol and 300 mL of water. Dilute with water to volume.
Palladium chloride solution
Dissolve 100 mg of palladium chloride in a mixture of 1 mL of hydrochloric acid and 50 mL of water in a 100-mL volumetric flask, heating on a steam bath to effect solution. Cool, dilute with water to volume, and mix. Store in an amber bottle and use within 30 days. On the day of use, transfer 50 mL to a 500-mL volumetric flask, add 4 mL of hydrochloric acid and 4.1 g of anhydrous sodium acetate, dilute with water to volume, and mix.
Assay preparation
Dilute 3.0 mL of Injection with
Acid-alcohol solution to 100 mL in a volumetric flask.
Procedure
Mix 10.0 mL each of the
Assay preparation and the
Standard preparation with 15.0 mL of
Palladium chloride solution, filter, if necessary, and concomitantly determine the absorbances of these solutions, against a reagent blank, in 1-cm cells at the wavelength of maximum absorbance at about 480 nm, with a suitable spectrophotometer. Calculate the quantity, in mg, of C
21H
26ClN
3OS in the volume of Injection taken by the formula:
0.1C(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.