Limit of iminodibenzyl—
Standard solution—
Dissolve an accurately weighed quantity of
USP Iminodibenzyl RS in alcohol, and dilute quantitatively and stepwise with alcohol to obtain a solution having a concentration of 50 µg per mL. Transfer 1.0 mL of this solution to a low-actinic, 25-mL volumetric flask, add 10 mL of a mixture of equal volumes of hydrochloric acid and alcohol, and mix.
Test solution—
Transfer 50.0 mg of Desipramine Hydrochloride to a low-actinic, 25-mL volumetric flask, add 10 mL of a mixture of equal volumes of hydrochloric acid and alcohol, and mix.
Procedure—
To the two flasks containing the
Standard solution and the
Test solution, and to a third flask containing 10 mL of a mixture of equal volumes of hydrochloric acid and alcohol to provide the blank, add slowly 5 mL of a 0.4% (v/v) solution of furfural in alcohol, mix, then add 5 mL of hydrochloric acid, and allow the flasks to stand in a constant-temperature bath at 25
for 3 hours. Dilute each flask with a mixture of equal volumes of hydrochloric acid and alcohol to volume, and mix. Concomitantly determine the absorbances of the solutions in 1-cm cells at the wavelength of maximum absorbance at about 565 nm, with a suitable spectrophotometer, using the blank to set the instrument: the absorbance of the solution obtained from the
Test solution is not greater than that obtained from the
Standard solution (0.1%).
Assay—
Dissolve about 0.6 g of Desipramine Hydrochloride, previously dried and accurately weighed, in 100 mL of glacial acetic acid, add 10 mL of
mercuric acetate TS, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically, using a calomel-glass electrode system. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 30.29 mg of C
18H
22N
2·HCl.
;)
197U
—