DETERMINATION OF IBUPROFEN IN ERYTHROCYTES AND PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A high-performance liquid chromatographic (HPLC) method is described f or the determination of ibuprofen in isolated erythrocytes and plasma. Before HPLC analysis ibuprofen was isolated by liquid-liquid extracti on from these biological matrices; methylene chloride proved to be the best of the organic solvents tested. For the sample of erythrocytes i t was necessary to carry out haemolysis prior to their extraction. HPL C was performed on a C-18 column with a mobile phase of methanol-water (220:100, v/v) acidified with perchloric acid to pH 3. Ultraviolet de tection was at 222 nm. This method has been applied to the quantificat ion of ibuprofen in rabbit erythrocytes and plasma for a pharmacokinet ics study.