Determination of nifedipine and its three principal metabolites in plasma and urine by automated electron-capture capillary gas chromatography.
A sensitive, efficient, linear and reproducible capillary gas chromatographic method with electron-capture detection was developed for the quantitation of nifedipine and its primary metabolite M-I in plasma together with the urinary and principal metabolites M-II and M-III. On-column, rather than split-splitless, injection was employed to obviate oxidative degradation of nifedipine to M-I. The photosensitivity of nifedipine was re-examined under laboratory conditions and nifedipine was found to have a half-life in excess of two days when amber glassware and darkroom manipulations under red light were used. The method can determine nifedipine and its metabolites in plasma and urine after a single oral dose of 5 mg and can be applied to measure M-I production by human liver microsomes.
Schmid
B J
BJ
Department of Pharmacology and Toxicology, St. Mary's Hospital Medical School, London, U.K.
Perry
H E
HE
Idle
J R
JR
D001322:Autoanalysis; D002849:Chromatography, Gas; D004563:Electrochemistry; D006207:Half-Life; D006801:Humans; D008027:Light; D009543:Nifedipine / Q000032:analysis* / Q000097:blood / Q000652:urine; D013696:Temperature
D009543:Nifedipine