Packaging and storage—
Preserve in tight, light-resistant containers. Store at 25
, excursions permitted between 15
and 30
.
Identification—
B:
A solution of it responds to the tests for
Chloride 
191
.
pH 791:
between 4.5 and 6.5, in a solution (1 in 100).
Loss on drying 731—
Dry about 500 mg, accurately weighed, at 105
for 1 hour: it loses not more than 0.3% of its weight.
Ordinary impurities 466—
Test solution:
alcohol.
Standard solution:
alcohol.
Eluant:
a mixture of methanol and ammonium hydroxide (100:1.5).
Visualization:
3.
Limits—
The sum of the intensities of all secondary spots obtained from the Test solution corresponds to not more than 1.0%.
Organic volatile impurities, Method I 467:
meets the requirements.
Assay—
Dissolve about 500 mg of Methadone Hydrochloride, accurately weighed, in a mixture of 10 mL of glacial acetic acid and 10 mL of
mercuric acetate TS, warming slightly if necessary to effect solution. Cool the solution to room temperature, add 10 mL of dioxane, then add
crystal violet TS, and titrate rapidly 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 34.59 mg of C
21H
27NO·HCl.
Auxiliary Information—
Staff Liaison :
Clydewyn M. Anthony, Ph.D., Scientist
Expert Committee : (MDCCA05) Monograph Development-Cough Cold and Analgesics
USP29–NF24 Page 1367
Pharmacopeial Forum : Volume No. 29(6) Page 1929
Phone Number : 1-301-816-8139
;)
