Standard preparation
[NOTEPrepare on the day of the assay.
]Dissolve an accurately weighed quantity of
USP Anileridine Hydrochloride RSin 0.1Nhydrochloric acid,and quantitatively dilute with the same solvent to obtain a solution having a known concentration of about 250µg per mL.(Each mg of anileridine hydrochloride is equivalent to 0.8286mg of anileridine.)
Procedure
Transfer 5.0mLeach of the
Standard preparation,the
Assay preparation,and 0.1Nhydrochloric acid to provide the blank to separate 200-mLvolumetric flasks.To each flask add 25mLof water,5mLof 1Nhydrochloric acid,and 5mLof sodium nitrite solution (1in 1000),and mix.Allow to stand for 2minutes,then add to each flask 5mLof ammonium sulfamate solution (1in 200),and mix.Allow to stand for 3minutes,then add 5mLof N-(1-naphthyl)ethylenediamine dihydrochloride solution (1in 1000),and mix.Allow to stand for 1hour,dilute with water to volume,and mix.Determine the absorbances of the solutions in 1-cm cells at the wavelength of maximum absorbance at about 560nm,with a suitable spectrophotometer,using the reagent blank to set the instrument.Calculate the quantity,in mg,of anileridine (C
22H
28N
2O
2)in each mLof the Injection taken by the formula:
(352.48/425.40)(0.5C/V)(AU/AS),
in which 352.48and 425.40are the molecular weights of anileridine and anileridine hydrochloride,respectively;
Cis the concentration,in µg per mL,of
USP Anileridine Hydrochloride RSin the
Standard preparation;Vis the volume,in mL,of Injection taken;and
AUand
ASare the absorbances of the solutions from the
Assay preparationand the
Standard preparation,respectively.