A rapid and sensitive LC-MS/MS method for analysis of iguratimod in human plasma: Application to a pharmacokinetic study in Chinese healthy volunteers

Simultaneous determination of iguratimod and its metabolite in rat plasma using a UPLC-MS/MS method: Application for drug-drug interaction

This aim of the work was to establish an acceptable sensitive assay based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for quantitatively analyzing the plasma concentrations of iguratimod (IGR) and its metabolite M2 in rats, and to further investigate the effect of fluconazole on the pharmacokinetics of IGR and M2. The mobile phase consisted of acetonitrile and water with 0.1% formic acid, was used to separate IGR, M2 and internal standard (IS) fedratinib on a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with the flow rate of 0.4 mL/min. Positive ion mode and multiple reaction monitoring (MRM) were used to construct the quantitative analysis. The calibration standard of IGR and M2 covered 2-10000 and 1-1000 ng/mL respectively, with the lower limit of quantification (LLOQ) as 2 ng/mL and 1 ng/mL respectively. In addition, selectivity, recovery, accuracy, precision, matrix effect and stability of the method validation program were well accepted in this work. Subsequently, this approach was used to assess the effect of fluconazole on the pharmacokinetics of IGR and M2 in rats. In the presence of 20 mg/kg fluconazole (experimental group), we found the main pharmacokinetic parameters were significantly altered when compared with 2.5 mg/kg IGR alone (control group). Among them, AUC(0-∞) and Cmax of IGR in the experimental group was 1.43 and 1.08 times higher than that of the control group, respectively. Moreover, we also found that the other main pharmacokinetic parameters of M2 had no significant changes, except t1/2z and Tmax. In conclusion, fluconazole significantly altered the main pharmacokinetics of IGR and M2 in rats. It implys that we should pay more attention to the adverse reaction of IGR when the concomitant use of fluconazole and IGR occur in the future clinical practice.

Efficacy and safety of iguratimod combined with methotrexate vs. methotrexate alone in rheumatoid arthritis : A systematic review and meta-analysis of randomized controlled trials

The current systematic review and meta-analysis aims to evaluate the efficacy and safety of iguratimod (IGU) combined with methotrexate (MTX) versus MTX alone in rheumatoid arthritis (RA). Two independent investigators searched for original randomized controlled trials (RCTs) related to the combination of IGU and MTX in RA published before November 1, 2019, in PubMed, Cochrane Library, Embase, the China National Knowledge Infrastructure (CNKI), the Chinese Biomedical Literature Database (CBM), and WanFang Data. Additionally, we searched clinical trial registry websites. We assessed the methodological quality of the included trials using the Cochrane Collaboration tool and the seven-point Jadad scale. Statistical analyses were performed using Review Manager (RevMan) 5.3 (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014). Meta-regression and publication bias analyses were performed using Stata version 14 software (StataCorp., College Station, TX, USA). A total of 7 RCTs consisting of 665 participants, with 368 participants in the active arm and 297 in the placebo arm, were included in the meta-analysis. The American College of Rheumatology (ACR) value was better in the IGU + MTX group than in the MTX alone group, with a pooled relative risk (RR) for ACR20 (American College of Rheumatology 20% improvement criteria), ACR50, and ACR70 of 1.40 (95% CI, 1.13-1.74), 2.09 (95% CI, 1.67-2.61), and 2.24 (95% CI, 1.53-3.28), respectively. The results of the meta-analysis demonstrated that there was no statistical significance in adverse events (1.06 (95% CI, 0.92-1.23)). The combined treatment is an effective, safe, and economical treatment option for patients who do not respond well to methotrexate alone or for patients who cannot afford expensive biologics that have no confirmed efficacy.