A validated UPLC-MS/MS method for determination of tebipenem in human plasma and its application to a pharmacokinetic study in healthy volunteers.

A rapid and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determining tebipenem (TBPM) in human plasma. Plasma samples were prepared following a single-step protein precipitation method using acetonitrile and 3-morpholinopropanesulfonic acid (MOPS, pH 7.0, 50 mM) which equal volume of plasma samples were added for stabilizing the analyte. Separation was achieved using an ACQUITY UPLC BEH C18 (1.7 μm, 2.1 × 50 mm) column. A repeated gradient program was employed for reducing the carryover effect, and the total chromatographic run time was 3.0 min. Method validation results showed TBPM was linear in its analytical range i.e. between 0.1-20 μg/mL (r>0.99), and the lower limit of quantification (LLOQ) was 0.1 μg/mL. The intra-run and inter-run precision (coefficient of variation, CV) was within 3.81%, and the accuracy (relative error, RE) was within ± 8.56%. The carryover was restricted below 8.1%. Matrix effects were minimal, and recovery of TBPM was 90.19-95.74%. The stability of TBPM in plasma sample stored at room temperature (25 °C) for 4 h, at -20 °C for 3 days, at -80 °C for 30 days, five freeze-thaw cycles at -80 °C and processed samples at auto sampler vials (8 °C) for 24 h were within 91.11-106.33%. Finally, the validated method was successfully applied to a pharmacokinetic study of TBPM in healthy volunteers after oral administration of tebipenem pivoxil (TBPM-PI).