Quantitative determination of ticlopidine hydrochloride in human plasma by high-performance liquid chromatography-electronspray ionization mass spectrometry.

A sensitive, selective and simple high performance liquid chromatographyelectrospray ionization-mass spectrometry (HPLC-ESI-MS) was developed and validated for the quantification of ticlopidine hydrochloride (CAS 53885-35-1) in human plasma using loratadine (CAS 79794-75-5) as internal standard (IS). Following liquid-liquid extraction, the analyte and the IS were extracted from plasma samples by n-hexane:isopropanol (95:5, v/v), separated by HPLC on a commercially available column (150 mm x 2.0 mm ID, 5 microm) with a mobile phase of acetonitrile: 10 mmol/L ammonium acetate buffer solution (85:15, v/v) and analyzed on a quadrupole mass spectrometer with ESI interface operating in the positive-ion mode. The correlation coefficient of the calibration curve was linear (r2 > 0.99) over the concentration range of 1-1000 ng/mL for ticlopidine hydrochloride. The intra- and inter-batch precisions were less than 15% of the relative standard deviation and the accuracy ranged from 85 to 115% in terms of percent accuracy. The limit of detection (LOD) of ticlopidine hydrochloride was 0.5 ng/mL. The extraction recovery of ticlopidine hydrochloride was more than 80%. The proposed method enables the unambiguous identification and quantification of ticlopidine hydrochloride for pharmacokinetic, bioavailability or bioequivalence studies.