The Development and Validation of the Accurate and Sensitive HPLC Method for Quantification of Mizoribine in Human Plasma and Its Clinical Applications

Background and Objectives: To establish a simple and reproducible High Performance Liquid Chromatography (HPLC) method for the determination of mizoribine in human plasma using glipizide as Internal Standard (IS). Methods: The mizoribine in plasma was precipitated with 10% perchloric acid and separated on a Phenomenex Luna NH2 (250 mm 4.6 mm, 5 μm) column with a mobile phase consisted of acetonitrile and 0.3% glacial acetic acid aqueous solution (48:52, V/V) at a flow rate of 1.0 mL/min. The detection wavelength was 280 nm and the column temperature was room temperature. Results: The assay exhibited a linear range of 0.05-10.0 μg/mL (r = 0.9992) and the lower limit of quantification was 0.05 μg/mL. The specificity, linearity, accuracy, precision and stability were in accordance to China Food and Drug Administration (CFDA) guidelines. Conclusion: Therefore, the method was successfully applied in the routine therapeutic mizoribine monitoring in Chinese kidney transplant patients after an oral administration of 100 mg (2 Bredinin® 50 mg tablets) or 150 mg (3 Bredinin® 50 mg tablets) mizoribine.