Packaging and storage—
Preserve in well-closed, light-resistant containers.
Identification—
B:
Ultraviolet Absorption 
197U
—
Solution:
1 mg per mL.
Medium:
methanol.
Absorptivities at 257 nm, calculated on the dried basis, do not differ by more than 3.0%.
C:
Dissolve about 20 mg in 5 mL of phosphoric acid: a green color is produced.
D:
To 5 mL of a solution (1 in 500) add bromine TS dropwise: a yellow precipitate, which dissolves on shaking, is formed. Addition of more bromine TS produces a precipitate that does not dissolve on shaking.
E:
A 5-mL portion of a solution (1 in 500) responds to the tests for
Chloride 191.
Ordinary impurities 466—
Test solution:
methanol.
Standard solution:
methanol.
Eluant:
a mixture of methanol and ammonium hydroxide (100:1.5).
Visualization:
17.
Organic volatile impurities, Method IV 467:
meets the requirements.
Assay—
Accurately weigh about 500 mg of Biperiden Hydrochloride, and dissolve in 80 mL of glacial acetic acid, warming slightly, if necessary, to effect solution. Cool, add 1 drop of
crystal violet TS and 10 mL of
mercuric acetate TS, and titrate with 0.1 N perchloric acid VS to a blue endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 34.79 mg of C
21H
29NO·HCl.
-bicyclo[2.2.1]hept-5-en-2-yl-
for 3 hours: it loses not more than 0.5% of its weight.