Employing ionization behaviors to resolve a trace-level impurity: determination of 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5- pyridinedicarboxylic acid di-2-[methyl-(phenylmethyl)amino]ethyl ester in nicardipine drug substance.
Maurin
M B
MB
Du Pont Merck Pharmaceutical Company, Wilmington, Delaware 19880-0336.
Vickery
R D
RD
Ma
P
P
Manalo
J
J
Hussain
M A
MA
D002852:Chromatography, Ion Exchange; D004340:Drug Contamination; D006863:Hydrogen-Ion Concentration; D009529:Nicardipine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry* / Q000592:standards; D011199:Potentiometry
C078981:XE 820; D009529:Nicardipine