Liquid-chromatographic assay of ibuprofen enantiomers in plasma.

摘要: This stereospecific "high-performance" liquid-chromatographic (HPLC) assay is suitable for pharmacokinetic studies of ibuprofen (IB). Very efficient extraction the drug and internal standard, (+/-)-2-(4-benzoylphenyl)butyric acid, from plasma with isooctane/isopropanol (95/5, by vol) followed sequential reaction enantiomers ethyl chloroformate (S)-(-)-1-(1-naphthyl)ethylamine. The reactions take place at ambient temperature in less than 4 min. naphthylethylamide derivatives IB standard are then extracted into chloroform. After organic layer evaporated, reconstituted residue chromatographed on a C18 reversed-phase column mobile phase acetonitrile/water/acetic acid/triethylamine (55/45/0.1/0.02 flow rate 1 mL/min. diastereoisomers, detected 232 nm, free interfering peaks have resolution factor 2.2. Within examined enantiomer concentration range 0.1 to 20 mg/L plasma, peak-area ratios varied linearly corresponding concentrations. We used study pharmacokinetics subject who took single 600-mg dose racemic drug.