High-performance thin-layer chromatographic determination of flurbiprofen in plasma

A high-performance thin-layer chromatographic (HPTLC) method for the assay of flurbiprofen in plasma is reported. The drug was extracted from acidified plasma with hexane-diethyl ether (80:20). The mobile phase composition was n-hexane-ethyl acetate-glacial acetic acid (60:30:10). Densitometric analysis of flurbiprofen was carried out at 247 nm. The calibration curves of flurbiprofen in methanol and in plasma were linear in the range 40-400 ng. The mean values of correlation coefficient, slope and intercept were 0.995 +/- 0.003, 0.075 +/- 0.002 and 4.39 +/- 0.05 for standard curves in methanol and 0.992 +/- 0.002, 0.066 +/- 0.007 and 3.40 +/- 0.72 for standard curves in plasma, respectively. The limit of quantitation for flurbiprofen in human plasma was 40 ng, and no interference was found from endogenous compounds. The recovery of flurbiprofen from human plasma using the described extraction procedure was about 87%. The coefficient of variation for within-day and between-day analyses was 2.53% and 3.96% for 200 ng and 1.76% and 2.30% for 400 ng flurbiprofen concentration, respectively. The method was utilized to monitor plasma concentration of flurbiprofen post administration of sustained release capsules in human patient volunteers.