Packaging and storage—
Preserve in well-closed containers.
Identification—
B:
Ultraviolet Absorption 
197U
—
Solution:
50 µg per mL.
Medium:
0.1 N hydrochloric acid.
Absorptivities at 273 nm, calculated on the dried basis, do not differ by more than 2.0%.
C:
To 10 mL of a solution (1 in 10) add 1 drop of
ferric chloride TS: a violet-blue color is produced.
pH 791:
between 4.0 and 5.0, in a solution (1 in 10).
Loss on drying 731—
Dry it in a suitable vacuum drying tube, using phosphorus pentoxide as the desiccant, for 3 hours: it loses not more than 0.5% of its weight.
Limit of dimethylaminophenol—
Dissolve about 500 mg, accurately weighed, in 5 mL of water in a separator. Add 5 mL of pH 8.0 phosphate buffer (see
Buffer Solutions in the section
Reagents, Indicators, and Solutions), and shake. Extract with five 20-mL portions of chloroform, pooling the extracts in a 100-mL volumetric flask, and add chloroform to volume. The absorbance of this solution, determined in a 1-cm cell at 252 nm, with a suitable spectrophotometer, is not more than that of a 1 in 200,000 solution of dimethylaminophenol in chloroform, similarly measured (0.1%).
Assay—
Transfer about 175 mg of Edrophonium Chloride, accurately weighed, to a suitable flask, and dissolve in about 20 mL of glacial acetic acid. Add 5 mL of
mercuric acetate TS, then add 1 drop of
crystal violet TS, and titrate with 0.1 N perchloric acid VS. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 20.17 mg of C
10H
16ClNO.
Auxiliary Information—
Staff Liaison :
Elena Gonikberg, Ph.D., Senior Scientist
Expert Committee : (MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine
USP31–NF26 Page 2040
Pharmacopeial Forum : Volume No. 29(5) Page 1475
Phone Number : 1-301-816-8251
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and 170