A validated UHPLC-MS/MS method for determination of TQ-B3203 in human plasma and its application to a pharmacokinetic study in Chinese patients with advanced solid tumor

TQ-B3203 is a new topoisomerase I inhibitor derived from camptothecin. In this paper, a simple and reliable ultra high-performance liquid chromatography-tandem mass spectrometric method was developed and validated for determination of TQ-B3203 in human plasma with TQ-B3203-d(8) used as the internal standard. Bis(p-nitrophenyl)phosphate (2 mol/L) was added to ensure the stability of TQ-B3203 in human plasma. Plasma samples were protein precipitated by methanol and processed samples were chromatographed on an AQUITY BEH C-8 column (50 x 2.1 mm, id 1.7 mu m) with acetonitrile and water (0.1% formic acid) as the mobile phase. The calibration curves showed good linearity (R >= 0.99) over the concentration range of 0.5-500 ng/mL. Within- and between-run precision were <= 5.8% and the accuracy was within the range of -8.3 to 14.0%. This method was further successfully applied to a pharmacokinetic study of TQ-B3203 in Chinese advanced solid cancer patients after administration of TQ-B3203 liposome injection.