Identification—
A:
The solution employed for measurement of absorbance in the
Assay exhibits UV maxima and minima at the same wavelengths as that of a similar solution of
USP Trifluoperazine Hydrochloride RS, concomitantly measured.
B:
Mix 5 mL of it with 5 mL of methanol: a 5-µL portion of this solution responds to Identification test D under Trifluoperazine Hydrochloride.
Assay—
[NOTE—Use low-actinic glassware.
] Transfer an accurately measured volume of Injection, equivalent to about 20 mg of trifluoperazine, to a 250-mL separator. Add 10 mL of 4 N sulfuric acid, and extract with three 25-mL portions of carbon tetrachloride. Discard the carbon tetrachloride after each extraction. Add 10 mL of ammonium hydroxide, and extract with five 40-mL portions of cyclohexane. Extract the combined cyclohexane extracts with five 50-mL portions of 0.1 N hydrochloric acid, collecting the aqueous extracts in a 500-mL volumetric flask. Dilute with 0.1 N hydrochloric acid to volume, and mix. Transfer 25.0 mL of this solution to a 100-mL volumetric flask, dilute with 0.1 N hydrochloric acid to volume, and mix. Concomitantly determine the absorbances of this solution and of a Standard solution of
USP Trifluoperazine Hydrochloride RS in the same medium having a known concentration of about 12 µg per mL in 1-cm cells at 278 nm and at the maximum at about 255 nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in mg, of trifluoperazine (C
21H
24F
3N
3S) in each mL of the Injection taken by the formula:
(407.51/480.43)(2
C/
V)(
A255 
A278)
U / (
A255 A278)
S,
in which 407.51 and 480.43 are the molecular weights of trifluoperazine and trifluoperazine hydrochloride, respectively,
C is the concentration, in µg per mL, of
USP Trifluoperazine Hydrochloride RS in the Standard solution,
V is the volume, in mL, of Injection taken, and the parenthetic expressions are the differences in the absorbances of the two solutions at the wavelengths indicated by the subscripts, for the assay solution (
U) and the Standard solution (
S), respectively.
11
—
USP Trifluoperazine Hydrochloride RS. USP Endotoxin RS.