Quantification of tenofovir in human plasma by solid-phase extraction and high-performance liquid chromatography coupled with UV detection

摘要

BACKGROUND: Tenofovir is used in the treatment of HIV and hepatitis virus infections. The aim of this work was to develop and validate an high-performance liquid chromatography coupled with ultraviolet detection assay that can be implemented in most laboratories for the purposes of therapeutic drug monitoring and pharmacokinetic studies. METHODS: Two hundred microliters of plasma sample was used for the assay. Sample processing was carried out with solid-phase extraction. Tegafur was used as the internal standard. The chromatographic separation was achieved on a C18 reverse-phase analytic column with a mobile phase consisting of sodium phosphate buffer (pH: 6.12; 20.0 mM)-acetonitrile- tetrabutylammonium hydroxide solution (pH: 13.64; 1.14 mM) (90.0:10.0:0.3, v/v/v). The detection was at 262 nm, and the column oven was set at 35°C. RESULTS: The linear range of the calibration curve was 20-2000 ng/mL (r > 0.999, n = 6). The absolute extraction recoveries were 97.4% ± 2.5% and 81.6% ± 0.8% for tenofovir and tegafur, respectively. The relative standard deviations were 2.3%-3.3% for the intraday and 2.8%-5.3% for the interday analyses. The accuracy was within 100% ± 7%. The successful application of this method in a pharmacokinetic study in Chinese HIV-infected patients confirmed its robustness and reliability. CONCLUSIONS: A validated and reproducible method has been established to quantify the concentration of tenofovir in human plasma by high-performance liquid chromatography coupled with ultraviolet detection.