Determination of Mizoribine in Human Plasma Using High-performance Liquid Chromatography: Application to a Pharmacokinetic Study in Chinese Renal Transplant Recipients

Abstract

A rapid, simple, and reproducible high-performance liquid chromatographic method (HPLC) was developed and validated for the determination of mizoribine in human plasma using cytarabine as internal standard (IS). The plasma samples of mizoribine were precipitated with 6% perchloric acid. The supernatant was separated on a reversed phase C18 column with a mobile phase of 10 mM KH2PO4 buffer solution (pH 6.3) containing 10 mM perchloric acid using isocratic elution (at flow rate 1.5 mL/min), and detected using an ultraviolet detector at 280 nm. The assay exhibited a linear range of 0.02-10.0 μg/mL for mizoribine in human plasma and the lower limit of quantification was 0.02 μg/mL. The method was statistically validated for linearity, accuracy, precision and selectivity. In addition, the method was successfully applied to estimate the pharmacokinetic parameters of mizoribine in Chinese kidney transplant patients following an oral administration of 100 mg mizoribine (2 Bredinin® 50 mg tablets).