Packaging and storage—
Preserve in tight, light-resistant containers.
Identification—
A:
The IR absorption spectrum of a 1 in 100 solution in carbon disulfide, in a 1.0-mm cell between 7 µm and 15 µm, exhibits maxima only at the same wavelengths as that of a solution prepared by dissolving 55 mg of
USP Chlorpromazine Hydrochloride RS in 3 mL of 1 N sodium hydroxide and extracting the resulting solution with 5.0 mL of carbon disulfide.
Loss on drying 
731
—
Dry it in vacuum at room temperature for 3 hours: it loses not more than 1.0% of its weight.
Other alkylated phenothiazines—
Dissolve 45.0 mg in 10 mL of methanol. Dissolve a suitable quantity of
USP Chlorpromazine Hydrochloride RS in methanol to obtain a concentration of 5 mg per mL
(Standard solution), and dilute it quantitatively and stepwise with methanol to obtain a concentration of 25 µg per mL (
Diluted standard solution). Apply separately 10 µL of each of the three solutions to the starting line of a thin-layer chromatographic plate coated with chromatographic silica gel mixture. Develop the chromatogram, using as the solvent system a freshly prepared mixture of equal volumes of ether and ethyl acetate saturated with ammonium hydroxide, until the solvent front has moved about 10 cm from the origin. Remove the plate from the chamber, and air-dry for 20 minutes. View under short-wavelength UV light: the area and intensity of any spot, other than the principal spot, from the solution of Chlorpromazine are not greater than those of the spot from the
Diluted standard solution (0.5%).
Organic volatile impurities, Method V 467:
meets the requirements.
Solvent—
Use dimethyl sulfoxide.
Assay—
Place about 750 mg of Chlorpromazine, accurately weighed, in a 250-mL conical flask, and dissolve in 25 mL of glacial acetic acid, warming gently on a steam bath to effect solution. Cool, add
crystal violet TS, and titrate with 0.1 N perchloric acid VS to a blue endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 31.89 mg of C
17H
19ClN
2S.
;)
