Identification—
A:
Triturate a portion of powdered Tablets, equivalent to about 50 mg of triflupromazine hydrochloride, with 5 mL of methanol, and centrifuge. A 10-µL portion of the supernatant meets the requirements of Identification test C under Triflupromazine Hydrochloride.
B:
The solution prepared from the Tablets for measurement of absorbance in the
Assay exhibits an absorbance maximum at 255 ± 2 nm.
Dissolution 
711
—
Medium:
0.01 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Time:
45 minutes.
Procedure—
Determine the amount of C
18H
19F
3N
2S·HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 305 nm on filtered portions of the solution under test, suitably diluted with
Medium, if necessary, in comparison with a Standard solution having a known concentration of
USP Triflupromazine Hydrochloride RS in the same
Medium.
Tolerances—
Not less than 75% (Q) of the labeled amount of C18H19F3N2S·HCl is dissolved in 45 minutes.
Assay—
Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 20 mg of triflupromazine hydrochloride, to a separator, add 10 mL of 0.1 N hydrochloric acid and 20 mL of water, and mix. Add 6 N ammonium hydroxide to render the mixture alkaline to litmus, add 1 mL in excess, and extract with five 50-mL portions of chloroform, passing each extract through anhydrous sodium sulfate into a 250-mL volumetric flask. Dilute with chloroform to volume, and mix. Evaporate 10.0 mL of this solution under reduced pressure to dryness, and dissolve the residue in 0.1 N hydrochloric acid to make 100.0 mL. Concomitantly determine the absorbances of this solution and of a Standard solution of
USP Triflupromazine Hydrochloride RS in the same medium having a known concentration of about 8 µg per mL in 1-cm cells at the wavelength of maximum absorbance at about 255 nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in mg, of C
18H
19F
3N
2S·HCl in the portion of Tablets taken by the formula:
2.5C(AU / AS),
in which
C is the concentration, in µg per mL, of
USP Triflupromazine Hydrochloride RS in the Standard solution, and
AU and
AS are the absorbances of the solution from the Tablets and the Standard solution, respectively.
