Chromatographic purity
Adsorbent:
chromatographic silica gel mixture.
Test solution
Transfer about 250mg of Nortriptyline Hydrochloride,accurately weighed,to a 10-mLvolumetric flask.Dissolve in and dilute with methanol to volume,and mix.
Standard solutions
Dissolve an accurately weighed quantity of
USP Nortriptyline Hydrochloride RSin methanol,and dilute quantitatively,and stepwise if necessary,with methanol to obtain a solution having a known concentration of about 25.0mg per mL(
Standard solution A).Dilute appropriate portions of this solution with methanol to obtain
Standard solutions B,
C,
D,
E,and
Fhaving known concentrations of 125,75,50,25,and 12.5µg per mL,respectively.The final concentrations of
Standard solutions B,
C,
D,
E,and
Frepresent 0.5%,0.3%,0.2%,0.1%,and 0.05%of
Standard solution Aconcentration,respectively.
Application volume:
5µL.
Developing solvent system:
a mixture of acetonitrile,methanol,and ammonium hydroxide (10:1:1).
Procedure
Apply equal volumes of the
Test solutionand
Standard solutions A,
B,
C,
D,
E,and
Fas directed in
Ordinary Impurities á466ñ.Examine the plate under short-wavelength UVlight,then spray the plate with Dragendorff's TS,dry the plate with a stream of nitrogen,and then spray with hydrogen peroxide TS:any secondary spot at an
RFvalue of 0.78relative to the nortriptyline spot in the
Test solutionis not greater than the principal spot for
Standard solution D;any other secondary spot in the
Test solutionis not more than 0.1%;and the sum of all secondary spots is not more than 0.5%.