Abstract

RAPID DETERMINATION OF IBUPROFEN CONCENTRATION IN HUMAN PLASMA BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Syed N. Alvi, Ahmed Yusuf, Eman Al Gaai and Muhammad M. Hammami*

ABSTRACT

A simple, precise, and rapid reversed-phase high performance liquid chromatography (HPLC) method for the determination of ibuprofen (IBU) in human plasma using gemfibrozil as an internal standard (IS) was developed and validated. Plasma samples containing ibuprofen were spiked with the IS, precipitated with methanol, and centrifuged. The compounds of interest were efficiently separated on Symmetry Shield RP18 column maintained at a temperature of 40 ºC, and detected with multi-wave length fluorescence detector (excitation/emission wavelength 230/ 275 nm). The mobile phase consisted of 0.01M dibasic ammonium phosphate (pH adjusted to 5.5 with phosphoric acid) and acetonitrile (45:55, v:v), and was delivered at a flow rate of 1.5 ml/min. The relationship between ibuprofen
concentration in plasma and peak area ratio of ibuprofen / IS was linear (R2 ≥ 9997) in the range of 0.25 – 60 μg/ml, the intra- and inter- day coefficient of variations (CV) were ≤ 3.8% and ≤ 2.9%, respectively. Extraction recoveries of ibuprofen and the IS were > 90%, whereas the accuracy (relative recovery) of ibuprofen measurement was 98% to 107% using quality control samples and 92% to 105% as determined by back calculation from peak area ratios of the calibration curves. The method was used to assess the stability of ibuprofen in human plasma under various conditions in the clinical laboratory. Further, it was successfully employed to measure ibuprofen levels in samples obtained normal volunteer.

Keywords: Ibuprofen, Gemfibrozil, Human plasma, HPLC.