Packaging and storage—
Preserve in tight, light-resistant containers.
USP Reference standard 
11
—
USP Prochlorperazine Maleate RS.
NOTE—Throughout the following procedures, protect test or assay specimens, the Reference Standard, and solutions containing them, by conducting the procedures without delay, under subdued light, or using low-actinic glassware.
Loss on drying 731—
Dry it in vacuum at 60
for 2 hours: it loses not more than 0.5% of its weight.
Ordinary impurities 466—
Test solution:
a mixture of methanol and 1 N sodium hydroxide (9:1).
Standard solution:
a mixture of methanol and 1 N sodium hydroxide (9:1).
Eluant:
a mixture of methanol and ammonium hydroxide (100:1).
Visualization:
1.
Organic volatile impurities, Method V 467:
meets the requirements.
Solvent—
Use dimethyl sulfoxide.
Assay—
Transfer to a beaker about 400 mg of Prochlorperazine Maleate, accurately weighed, and dissolve in 30 mL of chloroform, warming on a steam bath to effect solution. Add 100 mL of glacial acetic acid, cool to room temperature, and titrate with 0.05 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.05 N perchloric acid is equivalent to 15.15 mg of C20H24ClN3S·2C4H4O4.
