Homatropine Methylbromide
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C17H24BrNO3 370.28

8-Azoniabicyclo[3.2.1]octane, 3-(hydroxyphenylacetyl)oxy-8,8-dimethyl-, bromide, endo-.

3-Hydroxy-8-methyl-1h,5h-tropanium bromide mandelate [80-49-9].
» Homatropine Methylbromide contains not less than 98.5 percent and not more than 100.5 percent of C17H24BrNO3, calculated on the dried basis.
Packaging and storage— Preserve in tight, light-resistant containers.
A: Infrared Absorption 197K. [note—If differences are observed, dissolve the specimen and the Reference Standard separately in methanol, and recrystallize by adding dioxane to each solution.]
B: Ultraviolet Absorption 197U
Solution: 1 mg per mL.
Medium: alcohol.
Absorptivities at 258 nm, calculated on the dried basis, do not differ by more than 3.0%.
C: Mercuric-potassium iodide TS produces in a solution (1 in 50) a white or slightly yellowish precipitate, but no precipitation is caused by solutions of alkali hydroxides or carbonates, even in concentrated solutions of the substance (distinction from most alkaloids).
D: To a solution (1 in 50), add ammonium reineckate TS: a red precipitate is formed.
E: A solution (1 in 20) responds to the tests for Bromide 191.
pH 791: between 4.5 and 6.5, in a solution (1 in 100).
Loss on drying 731 Dry it at 105 for 3 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.2%.
Homatropine, atropine, and other solanaceous alkaloids— To 1 mL of a solution of it (1 in 50), add a few drops of 6 N ammonium hydroxide, shake the solution with 5 mL of chloroform, and evaporate the separated chloroform layer on a steam bath to dryness. Warm the residue with 1.5 mL of a solution made by dissolving 500 mg of mercuric chloride in 25 mL of a mixture of 5 volumes of alcohol and 3 volumes of water: no yellow or red color develops.
Assay— Dissolve about 700 mg of Homatropine Methylbromide, accurately weighed, in a mixture of 50 mL of glacial acetic acid and 10 mL of mercuric acetate TS. Add 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 37.03 mg of C17H24BrNO3.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Elena Gonikberg, Ph.D.
Senior Scientist
(MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 2560
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.