Identification
B:
Dissolve about 250 mg in 10 mL of water, render slightly alkaline with
sodium carbonate TS, extract the precipitate with ether, evaporate the ether extract on a steam bath to dryness, and dry the residue in vacuum at 60
for 1 hour: the mepivacaine so obtained melts between 149
and 153
.
C:
A solution (1 in 100) responds to the tests for
Chloride 191.
Chromatographic purity
Mix about 500 mg with 10 mL of water to obtain a test solution. Inject about 1 µL of this solution into a suitable gas chromatograph (see
Chromatography 621), equipped with a flame-ionization detector. Under typical conditions, the instrument contains a 1.8-m × 4-mm glass column packed with 3 percent phase G19 on packing S1A. The column is maintained at about 230
, and dry helium, flowing at the rate of about 40 mL per minute, is used as the carrier gas. Similarly inject about 1 µL of a Standard solution of
USP Mepivacaine Hydrochloride RS in water having a concentration of about 5 mg per mL. Locate the mepivacaine peak in each chromatogram. The total area of all extraneous peaks (except that of the solvent peak) recorded for the test solution, over a time span of not less than 1.3 × the retention time for mepivacaine, relative to the total area of all peaks does not exceed 0.4%.
Assay
Transfer about 550 mg of Mepivacaine Hydrochloride, accurately weighed, to a 200-mL beaker, and dissolve in 50 mL of glacial acetic acid, heating if necessary. 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 green endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 28.28 mg of C
15H
22N
2O·HCl.