Papaverine Hydrochloride
If you find any inaccurate information, please let us know by providing your feedback here
This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
C20H21NO4 · HCl 375.85
Isoquinoline, 1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-, hydrochloride.
6,7-Dimethoxy-1-veratrylisoquinoline hydrochloride CAS RN®: 61-25-6; UNII: 23473EC6BQ.
Papaverine Hydrochloride contains not less than 98.5 percent and not more than 100.5 percent of C20H21NO4 · HCl, calculated on the dried basis.
Packaging and storage—Preserve in tight, light-resistant containers. Store at 25°, excursions permitted between 15° and 30°.
USP Reference standards 〈11〉—
USP Papaverine Hydrochloride RS
Completeness of solution—A 1 in 15 solution in chloroform is clear and free from undissolved solid.
Identification—
Change to read:
A: Spectroscopic Identication Tests 〈197〉, Infrared Spectroscopy: 197K (CN 1-May-2020) .
Change to read:
B: Spectroscopic Identication Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U (CN 1-May-2020)
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).
Loss on drying 〈731〉—Dry it at 105° for 2 hours: it loses not more than 0.5% of its weight.
Residue on ignition 〈281〉: not more than 0.1%.
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.
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 C20H21NO4 · HCl.
