A new validated method for the determination of tofacitinib in human serum and pharmaceutical dosage form by HPLC-DAD

The aim of this study was to develop a novel, rapid, simple, validated, and practically applicable HPLC-DAD method for tofacitinib analysis in human serum and pharmaceutical dosage. In serum test samples, tofacitinib and caffeine (internal standard, IS) were extracted using a simple liquid-liquid extraction process. Tofacitinib and caffeine were well resolved from the RP-HPLC system. The separation was achieved on XBridge, C18 (250 × 4.6 mm, 5 µm) analytical column with diode array detector (DAD) (285 nm) and isocratic elution. The mobile phase consists of a mixture of acetonitrile:NaH 2 PO 4 (20 mM) (35:65; v/v) (pH 4.2) at 1.1 mL min −1 flow rate. Tofacitinib and caffeine (IS) were eluted at 3.80 and 2.79 min, respectively, and the total run time was 5 min. Method validation was performed according to the ICH guidelines. The calibration curve was linear over a concentration range of 0.1–1.25 μg mL −1 ( r 2 > 0.995) mobile phase and serum. LOD and LOQ were found as 0.02 μg mL −1 and 0.06 μg mL −1 , respectively in human serum test samples. The recovery values for tablet formulation and spiked human serum for 1.0 μg mL −1 were found as 98.44% and 100.10% ( n = 6) respectively. A simple, sensitive, specific, and new high-performance liquid chromatographic (HPLC) method has been developed and validated for the determination of tofacitinib in human serum and tablet (Jandark) formulation. The validated HPLC method was successfully applied to the tofacitinib assay of human serum and tablet formulation.