Determination of triflusal in human plasma by high performance liquid chromatography with automated column switching system

An analytical method of triflusal in human plasma was developed using semi- microbore HPLC equipped with automated column switching system. p-Toluic ac id which is the structural analogue of triflusal, was used as an internal s tandard and 2 M HCl was employed as a stabilizer. The load phase and mobile phase were prepared using acetonitrile and 20 mM KH2PO4 with the volume ra tios of 10:90 (pH 2.5) and 43:57 (pH 2.3), respectively. The signals were m onitored by a UV detector at 275 nm with flow-rate of load phase, 500 mu L/ min, and mobile phase, 100 mu L/min, respectively. The retention time of tr iflusal and p-toluic acid was about 20.2 min and 16.4 min, respectively. Th e detection limit of triflusal in human plasma was 0.01 mu g/mL and the lim it of quantitative analysis was 0.05 mu g/mL. The accuracy of the assay was from 97.76% to 116.51% while the intra-day and inter-day coefficient of va riation of the same concentration range was less than 15%. This analytical method demonstrated excellent sensitivity, reproducibility, specificity, an d speed using the plasma sample. This method could be successfully applied to evaluate the bioavailability of triflusal in human subjects without time -consuming sample clean-up after oral administration of low dose.