Enantioselective analysis of ibuprofen in human plasma by anionic cyclodextrin-modified electrokinetic chromatography

• Published in: Electrophoresis Vol. 23; no. 17; pp. 3041 - 3047
• Main Authors: Jabor, Valquíria A. P., Lanchote, Vera L., Bonato, Pierina S.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-09-2002; WILEY‐VCH Verlag
• Subjects: Capillary electrophoresis; Chromatography, Micellar Electrokinetic Capillary; Cyclodextrins - chemistry; Drug Monitoring - methods; Electrophoresis, Capillary - methods; Enantiomeric separation; Humans; Ibuprofen; Ibuprofen - administration & dosage; Ibuprofen - blood; Ibuprofen - pharmacokinetics; Plasma samples; Reproducibility of Results; Stereoisomerism; Validation
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/1522-2683(200209)23:17<3041::AID-ELPS3041>3.0.CO;2-Q

This paper reports the development of a rapid method for the enantioselective analysis of the nonsteroidal anti‐inflammatory drug ibuprofen in human plasma by capillary electrophoresis employing the anionic cyclodextrin‐modified electrokinetic chromatography mode. Sample cleanup was carried out by acidification with HCl followed by liquid‐liquid extraction with hexane:isopropanol (99:1 v/v). The complete enantioselective analysis was performed within 10 min, using 100 mmol L–1 phosphoric acid/triethanolamine buffer, pH 2.6, containing 2.0% w/v sulfated β‐cyclodextrin as chiral selector; fenoprofen, another nonsteroidal anti‐inflammatory drug, was used as internal standard. The calibration curves were linear over the concentration range of 0.25–125.0 νg mL–1 for each enantiomer of ibuprofen. The mean recoveries for ibuprofen enantiomers were up to 85%. The enantiomers studied could be quantified at three different concentrations (0.5, 5.0 and 50.0 νg mL–1) with a coefficient of variation and relative error not higher than 15%. The quantitation limit was 0.2 νg mL–1 for (+)‐(S)‐ and (−)‐(R)‐ibuprofen using 1 mL of human plasma. The plasma endogenous compounds and other drugs did not interfere with the present assay. The analysis of real plasma samples obtained from a healthy volunteer after administration of 600 mg of racemic ibuprofen showed a maximum plasma level of 29.6 and 39.9 νg mL–1 of (−)‐(R)‐ and (+)‐(S)‐ibuprofen, respectively, and the area under plasma concentration‐time curve AUC0‐∝ (+)‐(S)/AUC0‐∝ (−)‐(R) ratio was 1.87.