Isoquinoline, 1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-, hydrochloride.
6,7-Dimethoxy-1-veratrylisoquinoline hydrochloride
[
61-25-6].
Packaging and storage—
Preserve in tight, light-resistant containers. Store at 25
, excursions permitted between 15
and 30
.
Completeness of solution—
A 1 in 15 solution in chloroform is clear and free from undissolved solid.
Identification—
B: Ultraviolet Absorption 
197U
—
Solution:
2.5 µg per mL.
Medium:
0.1 N hydrochloric acid.
Absorptivities at 251 nm, calculated on the dried basis, do not differ by more than 3.0%.
C:
A solution (1 in 50) responds to the tests for
Chloride 191.
pH 791:
between 3.0 and 4.5, in a solution (1 in 50).
Limit of cryptopine, thebaine, or other organic impurities—
Dissolve 50 mg in 2 mL of sulfuric acid in a small test tube: the resulting solution is not more yellow-brown in color than
Matching Fluid S (see
Readily Carbonizable Substances Test 271), and it is not more pink than a standard prepared, in equal volume, by diluting 3.0 mL of 0.1 N potassium permanganate with water to 1000 mL.
Organic volatile impurities, Method IV 467:
meets the requirements.
Assay—
Dissolve about 700 mg of Papaverine Hydrochloride, accurately weighed, in 80 mL of glacial acetic acid; add 10 mL of
mercuric acetate TS and 1 drop of
crystal violet TS; and titrate with 0.1 N perchloric acid VS to a blue-green endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 37.59 mg of C
20H
21NO
4·HCl.
;)