Packaging and storage—
Preserve in tight, light-resistant containers.
Identification—
Transfer a portion of finely powdered Tablets, equivalent to about 10 mg of fluphenazine hydrochloride, to a separator, and to a second separator transfer 10 mg of
USP Fluphenazine Hydrochloride RS. Add 5 mL of water and 20 mL of dilute hydrochloric acid (1 in 120) to each separator, shake for 10 minutes, and to each mixture add 20 mL of chloroform-saturated sodium carbonate solution (1 in 10). Extract each mixture with five 20-mL portions of chloroform, shaking gently to avoid emulsion formation, and pass the extracts through separate chloroform-washed cotton filters into separate 150-mL beakers. Evaporate the extracts on a steam bath to dryness, and dissolve the residues in 0.5-mL portions of a mixture of 4 volumes of methanol and 1 volume of water. Apply 10 µL of each solution to a suitable thin-layer chromatographic plate (see
Chromatography 
621
) coated with a 0.25-mm layer of chromatographic silica gel mixture. Allow the spots to dry, and develop the chromatogram in a solvent system consisting of a mixture of acetone, cyclohexane, and diethylamine (40:15:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, and allow the solvent to evaporate. Locate the spots on the plate by lightly spraying with a solution of sulfuric acid in methanol (2 in 5): the
RF value and color of the principal spot obtained from the test solution correspond to those obtained from the Standard solution.
Dissolution 711—
Medium:
0.01 N hydrochloric acid; 900 mL.
Apparatus 1:
100 rpm.
Time:
45 minutes.
Procedure—
Determine the amount of C
22H
26F
3N
3OS·2HCl dissolved by employing the procedure set forth in the
Assay, with the following differences: in the
Mobile phase, use 0.3% triethylamine; in the
Assay preparation, dilute the amount of sample to be withdrawn with an equal volume of
Mobile phase; in the
Standard preparation, use a concentration and composition similar to that of the
Assay preparation; in the
Chromatographic system, use a flow rate of about 2.0 mL per minute; in the
Procedure, inject a volume of about 100 µL.
Tolerances—
Not less than 75% (Q) of the labeled amount of C22H26F3N3OS·2HCl is dissolved in 45 minutes.
Assay—
Assay preparation—
Transfer 6 Tablets to a suitable volumetric flask, add Diluent solution, shake for 1 hour, and sonicate for 10 minutes or until a fine suspension is obtained. Dilute quantitatively, and stepwise if necessary, with Diluent solution to obtain a final concentration of 0.06 mg of fluphenazine hydrochloride per mL. Filter, discarding the first 5 mL of the filtrate.
Procedure—
Separately inject equal volumes (about 25 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of fluphenazine hydrochloride (C
22H
26F
3N
3OS·2HCl) in the portion of Tablets taken by the formula:
100CT(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Fluphenazine Hydrochloride RS in the
Standard preparation; T is the labeled quantity, in mg, of fluphenazine hydrochloride in the Tablet; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
