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Redox properties of isradipine and its electrochemical detection in the HPLC determination of the compound in human serum
Author(s) -
Takamura Kiyoko,
Kusu Fumiyo,
AbdelWadood Hanaa,
ElRabbat Nawal,
Saleh Gamal,
Refaat Ibrahim
Publication year - 2000
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/1099-0801(200011)14:7<453::aid-bmc5>3.0.co;2-7
Subject(s) - chemistry , isradipine , detection limit , cyclic voltammetry , acetonitrile , chromatography , electrochemistry , analytical chemistry (journal) , high performance liquid chromatography , dihydropyridine , electrode , organic chemistry , calcium
The electrochemical behaviour of isradipine in a mixed solution of Britton–Robinson buffer (pH 11.8):acetonitrile:methanol (6:3:1, v/v) was studied by cyclic voltammetry and spectroelectrochemistry using an optically transparent thin layer electrode of carbon cloth. The cyclic voltammogram showed several peaks whose shape and potentials depended on the pH. The peak at 330 nm, corresponding to the absorbance of the dihydropyridine ring, disappeared after electrolysis at a potential that was more positive than the oxidation peak. The oxidation peak corresponds to the oxidation of the dihydropyridine ring. Peak height at pH 11.8 was proportional to isradipine concentration. On the basis of the redox properties of isradipine, HPLC was conducted applying electrochemical detection on a polybutadiene coated alumina column using an alkaline mobile phase. The method was applied for the determination of isradipine content in human serum. A good linear relationship between isradipine concentration and peak height was found in the concentration range of 2–200 ng/mL with a correlation coefficient of 0.9924. The detection limit was 0.5 ng/mL. The within‐day and day‐to‐day variation were examined for control human serum and percentage relative standard deviation ranged from 0.5 to 6.7. Interference from many other coadministered drugs was studied in the specified experimental conditions. Photo and heat stabilities of the compound were also studied. Copyright © 2000 John Wiley & Sons, Ltd.