A sensitive HPLC method with fluorescence detection for quantification of pemigatinib in human plasma samples and its in-vivo application to pharmacokinetic study in rats.

Cholangiocarcinoma is a lethal tumour of the bile ducts. Cholangiocarcinoma fibroblast growth factor receptor gene fusions forms can be targeted by Pemigatinib (PGT). PGT a recently approved kinase inhibitor by the US-FDA, has its approval accelerated due to the disease viciousness. Development of a sensitive yet available and economical analytical platform to quantify PGT in human plasma is genuinely needed. Enabling monitoring of the therapeutic plan, hence, ensuring the drug efficacy and safety through pharmacokinetic studies. High-performance liquid chromatography with fluorescence detector (HPLC-FD) method is proposed using the native fluorescence of PGT. PGT and seliciclib (internal standard) chromatographic conditions optimisation, revealed favourable use of isocratic mobile phase consisting of methanol:ammonium acetate buffer (70:30v/v, pH5.0) pumped into C18-column (150 mm length × 4.6 mm internal diameter, 5 μm particle size), at 1 mL min-1 flow rate. PGT and seliciclib fluorescence excitation and emission were measured at 280 and 360 nm, respectively. Validation of the HPLC-FD method was processed based on the International Council for Harmonization guidelines. The method linearity range was 5-300 ng mL-1. The limits of detection and quantification were 2.8 and 8.5 ng mL-1, respectively. High precision and accuracy indicated by relative standard deviation ≤ 5.2, and recovery values of 95.4-102.2 %. Evident of the method greenness was verified by green analytical chemistry metric tools. HPLC-FD method was successfully applied to study PGT pharmacokinetics in rats. In conclusion, this study introduces a reliable analytical method of PGT in plasma for routine use in therapeutic drug monitoring for quality assurance and clinical follow-up.