Development and validation of an LC-MS/MS method for the determination of pelubiprofen and its active metabolite, trans-alcohol, in human plasma and its application to pharmacokinetic study

Pharmacokinetic Interactions Between Pelubiprofen and Eperisone Hydrochloride: A Randomized, Open-label, Crossover Study of Healthy Korean Men

PURPOSE

Pelubiprofen is a novel nonsteroidal anti-inflammatory, analgesic, and antipyretic drug with at least similar efficacy and better tolerability compared with other nonsteroidal anti-inflammatory, analgesic, and antipyretic drugs such as naproxen and aceclofenac. Eperisone hydrochloride is a centrally acting muscle relaxant that performs by blocking calcium channels. The combined use of pelubiprofen and eperisone hydrochloride is increasingly anticipated to promote the clinical effectiveness of pelubiprofen in relieving musculoskeletal symptoms of osteoarthritis, rheumatoid arthritis, and low back pain. No published data are yet available, however, regarding the pharmacokinetic interactions between these 2 drugs when administered concurrently. The objective of this study was to evaluate any pharmacokinetic interactions between pelubiprofen and eperisone hydrochloride in healthy Korean male volunteers.

METHODS

This was a randomized, open-label, crossover study. Each participant was randomly assigned to 1 of 6 treatment sequences and orally received either 45-mg sustained-release pelubiprofen, 75-mg sustained-release eperisone hydrochloride, or both as a single dose in each treatment period, with a 7-day washout period between each treatment. Serial blood samples were collected over 24 hours after dosing, and plasma concentrations of each drug and the major active metabolite of pelubiprofen (trans-alcohol pelubiprofen) were determined by using a validated HPLC-MS/MS system. Pharmacokinetic analyses were conducted by using noncompartmental methods.

FINDINGS

A total of 24 men (mean ± standard deviation of: age, 29 ± 4 years; weight, 72.5 ± 7.8 kg; body mass index, 23.4 ± 1.9 kg/m²) were enrolled, and 23 participants completed the study. For pelubiprofen, the geometric mean ratios (90% CIs) of C_max and AUC_0-∞ were 1.02 (0.87-1.19) and 0.97 (0.88-1.07), respectively. For the major active metabolite of pelubiprofen (trans-alcohol pelubiprofen), the geometric mean ratios (90% CIs) of C_max and AUC_0-∞ were 1.05 (0.98-1.13) and 1.04 (1.01-1.07). For eperisone, the geometric mean ratios (90% CIs) of C_max and AUC_0-∞ were 0.87 (0.67-1.15) and 1.05 (0.85-1.30). None of the study participants experienced serious adverse events during the study.

IMPLICATIONS

No clinically significant changes were noted in the pharmacokinetic interactions of pelubiprofen, the major active metabolite of pelubiprofen (trans-alcohol pelubiprofen), and eperisone hydrochloride between monotherapy and combination therapy with 45-mg sustained-release pelubiprofen and 75-mg sustained-release eperisone hydrochloride.

Development and validation of a highly sensitive LC-MS/MS-ESI method for quantification of IIIM-019-A novel nitroimidazole derivative with promising action against Tuberculosis: Application to drug development

The study aims to illustrate an analytical validation of a rapid and sensitive liquid chromatography (LC) coupled to tandem mass spectrometry (MS-MS) and electrospray ionization (ESI) method for quantification of IIIM-019 (a novel nitroimidazole derivative with potential activity against Tuberculosis) in mice plasma. The extraction of the analyte and the internal standard (Tolbutamide) from the plasma samples involves protein precipitation using acetonitrile. The chromatographic separation was accomplished using a gradient mode and the mobile phase comprised of acetonitrile and 0.1% formic acid in water. The flow rate used was 0.7 ml/min on a C18e high performance Chromolith column. IIIM-019 and Tolbutamide (IS) were analyzed by combined reversed-phase LC/MS-MS with positive ion electrospray ionization. The MS-MS ion transitions used were 533>170.1, 533>198 for IIIM-019 and 271>74, 271>155 for internal standard (IS) respectively. The method was linear over a concentration range of 0.5-1000 ng/ml and the lower limit of quantification was 0.50 ng/ml. The entire study was validated for accuracy, precision, linearity, range, selectivity, lower limit of quantification (LLOQ), recovery, and matrix effect in accordance with the FDA guidelines of method validation. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The intra and inter-day precisions were in the range of 0.51-11.18% and 0.51-7.55%. The pharmacokinetics was performed on male Balb/c mice by oral (2.5mg/kg), intraperitoneal (2.5mg/kg) and intravenous (1mg/kg) routes. The oral bioavailability of IIIM-019 was 51.6%. The method was also applied successfully in determining microsomal stability wherein the compound was found to be very slightly metabolized by rat liver microsomes.

Simultaneous determination of corynoline and acetylcorynoline in human urine by LC-MS/MS and its application to a urinary excretion study

Corynoline and acetycorynoline, the major active components derived from Corydalis bungeana Herba, showed multiple pharmacological activities. However, quantification of the two compounds in human urine has not been reported. A simple liquid chromatography with tandem mass spectrometry method for the simultaneous determination of corynoline and acetycorynoline in human urine has been developed and fully validated. The analytes were extracted from urine samples by simple liquid-liquid extraction. Chromatographic separation was achieved on a Hedera ODS-2C18 column with the mobile phase of water (containing 0.5% formic acid) and acetonitrile (28:72, v/v) at a flow rate of 0.4mL/min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring via an electrospray ionization source in positive mode. The monitored ion transitions were m/z 368.1→289.1 for corynoline, m/z 410.2→289.2 for acetycorynoline and m/z 380.2→243.2 for donepezil (internal standard), respectively. The calibration curves were linear (correlation coefficients>0.9970) over the concentration ranges of 3.0-3000pg/mL for corynoline and 3.0-1000pg/mL for acetycorynoline. The established method was highly sensitive with the lower limit of quantification (LLOQ) of 3.0pg/mL for both analytes. The intra- and inter-day precision was lower than 10% in terms of relative standard deviation for the low, medium, and high quality control samples, and lower than 16% for the LLOQ samples of the analytes. The accuracy was within ±10% in terms of relative error for both analytes. The method was successfully applied to a urinary excretion study after oral administration of the Chinese medicine formula Shuanghua Baihe tablets in healthy volunteers. The urinary excretion profiles of corynoline and acetycorynoline in human were first reported. The results of this study suggest that renal excretion was not the main excretion pathway of corynoline and acetycorynoline in humans.