Simultaneous quantification of donafenib, sorafenib, and their N-oxide metabolites in rat plasma using a HPLC-MS/MS method.

Donafenib and sorafenib are small molecule chemotherapy drugs for the management of hepatocellular carcinoma, with donafenib being a deuterated derivative of sorafenib. To date, a high liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method that quantify donafenib, sorafenib, and their main metabolites has not yet been developed. The objective of this study was to establish a HPLC-MS/MS method for the simultaneous detection of donafenib, donafenib-N-oxide, sorafenib, and sorafenib-N-oxide and for the pharmacokinetic studies in rat. The extraction of all analytes was achieved by simple protein precipitation utilizing acetonitrile. The Waters XBridge C18 column (2.1 × 100 mm, 3.5 µm) was selected, and the analytes could be efficiently separated and quantitated during a 2.8 min gradient elution procedure. The method was linear within the predefined quantification ranges and provided acceptable precision (%CV < 9.4%), reproducible extraction recovery (99.4%-111.5%), and low matrix effect (88.1%-98.6%). The hemolysis effect did not interfere with the quantification of all analytes, and similar results were obtained by changing the anticoagulant K2-EDTA to heparin or sodium citrate. Plasma pharmacokinetics revealed that the values of t1/2, Cmax, and AUC0-t of donafenib were 1.4-, 6.2-, and 3.1-fold higher than those of sorafenib, respectively. In conclusion, the proposed bioassay was successfully applied to pharmacokinetic studies in rat after administration of donafenib and sorafenib. Our work not only improves the bioanalytical method for determining the plasma concentrations of donafenib, sorafenib, and their N-oxide metabolites, but also provides a scientific reference for clinical pharmacokinetic studies.

Effects of the CYP3A inhibitors, voriconazole, itraconazole, and fluconazole on the pharmacokinetics of osimertinib in rats.

Background: Osimertinib, as third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is the first-line treatment approved to treat advanced T790M mutation-positive tumors. Triazole antifungals are therapeutic drugs for cancer patients to reduce the risk of opportunistic fungal infections. Our objective was to investigate whether three triazole antifungals (voriconazole, itraconazole, and fluconazole) could change the pharmacokinetics of osimertinib in rats. Methods: The adult male Sprague-Dawley rats were randomly divided into four groups (n = 6): control (0.3% CMC-Na), and voriconazole (20 mg/kg), itraconazole (20 mg/kg), or fluconazole (20 mg/kg) combined with osimertinib (10 mg/kg) group. Tail vein blood samples were collected into heparin tubes at various time points within 0-48 h after osimertinib administration. Osimrtinib's plasma concentration was detected using HPLC-MS/MS system equipped with a Waters XBridge C18 column, with the mobile phase consisting of acetonitrile and 0.2% formic acid water at a flow rate of 0.5 mL/min. Results: Co-administration with voriconazole or fluconazole increased the Cmax of osimertinib by 58.04% and 53.45%, respectively; the AUC0-t increased by 62.56% and 100.98%, respectively. However, when co-administered with itraconazole, the Cmax and AUC0-t of osimertinib only increased by 13.91% and 34.80%, respectively. Conclusions: Our results revealed that the pharmacokinetics of osimertinib were significantly changed by voriconazole and fluconazole in rats, whereas it was slightly affected by itraconazole. This work will contribute to a more comprehensive understanding of the pharmacokinetic properties of osimertinib when co-administered with triazole antifungals.

Development and validation of a novel LC-MS/MS method for simultaneous quantitative determination of tyrosine kinase inhibitors in human plasma.

The objective of this study was to develop and validate a simple, rapid, and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of three tyrosine kinase inhibitors (ceritinib, osimertinib, and crizotinib) in human plasma using a single-step protein precipitation extraction. Chromatographic separation was achieved using a Waters X Bridge C18 (2.1 mm × 100 mm, 3.5 µm) and gradient elution with 0.2 % formic acid in water and acetonitrile. The total run time was 4.0 min, and the injection volume was 5 µL. The analytes were detected in the multiple reaction monitoring mode using electrospray ionization with positive ion mode. The m/z transitions of ceritinib, osimertinib, crizotinib and nilotinib were 558.0 â†’ 433.2, 500.0 â†’ 72.1, 450.0 â†’ 259.3, and 530.0 â†’ 289.1, respectively. The method was linear in the range of 2-500 ng/mL with lower limit of quantification of 2 ng/mL. Based on the guidelines on bioanalytical methods by the FDA, the validation studies demonstrated that the three analytes were both precise and accurate at four concentration levels, and the coefficient of variation was < 10.59 % and accuracy was > 88.26 %. We present a simple, rapid, and sensitive method for the simultaneous quantification of ceritinib, osimertinib, and crizotinib in human plasma by LC-MS/MS, which could be used in routine therapeutic drug monitoring.