Simultaneous determination of moxifloxacin with NSAIDs in API, dosage and serum by reverse phase high-performance liquid chromatography: Application to in vitro drug interactions

Experimental design is a significant tool for optimization and validation for the development of HPLC methods to determine API in both human serum and pharmaceutical formulations. In this study, RP-HPLC method is developed and validated for the simultaneous determination of moxifloxacin and NSAIDs. In this experiment, Purospher STAR C18 column with optimum assay conditions (10:90, v/v, water: methanol, pH 2.75) used as mobile phase having flow rate of 1.5mL min^-1 and screened at 240 nm. The experimental results exhibit reliability through accuracy (98-102%), precision (0.011-1.85%) and linearity (R²>0.999) in range of 0.15-40μgmL^-1. The LOD and LOQ limits for moxifloxacin and NSAIDs are found to be 0.015 and 0.046 μgmL^-1 respectively. The significant outcomes conclude that the developed method for assay is effectively suitable to human serum and pharmaceutical formulations and there is no interference from excipients of tablets and serum. The proposed method is useful for drug-interaction and investigation of moxifloxacin with NSAIDs.

A simple and sensitive HPLC-fluorescence method for the determination of moxifloxacin in human plasma and its application in a pharmacokinetic study

A simple sample preparation technique coupled with the specific and sensitive fluorescence detection for the determination of moxifloxacin in human plasma was developed and fully validated. Levofloxacin was chosen as an internal standard. Chromatographic separation was achieved using a Shiseido C18 MGII (250×4.6mm i.d.; 5 μm) column under an isocratic mobile phase comprising of 50 mM potassium dihydrogen phosphate (pH 2.4) - acetonitrile (77:23, v/v) at a flow rate of 1.5 mL/min. Fluorescence detection was optimized for the determination of moxifloxacin in human plasma at an excitation wavelength of 296 nm and an emission wavelength of 504 nm. The total chromatographic run time was 8 min with the retention times of moxifloxacin and internal standard at 6.5 and 3.0 min, respectively. Calibration curves were established over the dynamic range of 20-3000 ng/mL. The analytical method was validated as per US-FDA and EMA guidelines for specificity, sensitivity, linearity, accuracy, precision, recovery, hemolytic effect, lipemic effect, dilution integrity and stability. The validated analytical method was successfully applied in a pharmacokinetic study of a single-dose oral administration of a moxifloxacin 400 mg tablet in Thai healthy volunteers.

Elevated Plasma Moxifloxacin Concentrations and SLCO1B1 g.-11187G>A Polymorphism in Adults with Pulmonary Tuberculosis

Moxifloxacin exhibits concentration-dependent prolongation of human QTc intervals and bactericidal activity against Mycobacterium tuberculosis However, moxifloxacin plasma concentrations are variable between patients. We evaluated whether human gene polymorphisms affect moxifloxacin plasma concentrations in tuberculosis patients from two geographic regions. We enrolled a convenience sample of 49 adults with drug-sensitive pulmonary tuberculosis from Africa and the United States enrolled in two treatment trials of moxifloxacin as part of multidrug therapy. Pharmacokinetic parameters were evaluated by noncompartmental techniques. Human single-nucleotide polymorphisms of transporter genes were evaluated by analysis of covariance (ANCOVA) on moxifloxacin exposure and the peak (maximum) concentration (Cmax). The moxifloxacin area under the concentration-time curve from 0 to 24 h (AUC0-24) and Cmax were significantly increased by the drug milligram-per-kilogram dosage and the genotype of variant g.-11187G>A in the SLCO1B1 gene (rs4149015) but not by geographic region. The median moxifloxacin AUC0-24 was 46% higher and the median Cmax was 30% higher in 4 (8%) participants who had the SLCO1B1 g.-11187 AG genotype than in 45 participants who had the wild-type GG genotype (median AUC0-24 from the model, 34.4 versus 23.6 μg · h/ml [P = 0.005, ANCOVA]; median Cmax from the model, 3.5 versus 2.7 μg/ml [P = 0.009, ANCOVA]). Because moxifloxacin exhibits concentration-dependent prolongation of human QTc intervals and prolonged QTc intervals are associated with cardiac arrhythmia, further study is needed to evaluate the risk associated with the SLCO1B1 g.-11187G>A variant. (This study has been registered at ClinicalTrials.gov under identifier NCT00164463.).