Biomedical Chromatography最新文献

Preparative chromatographic enantioseparation is now the preferred technique for obtaining milligram quantities of pure enantiomers in the initial phase of development of a therapeutic compound. Supercritical fluid chromatography offers several advantages over liquid chromatography and was therefore selected for the preparative enantioseparation of a new potential anti-inflammatory molecule. Approximately 10 mg of each of the two enantiomers was successfully prepared using a Chiralpak AD-H (tris-3,5-dimethylphenylcarbamate of amylose) polysaccharide-based stationary phase with 40% of ethanol as a co-solvent, using a stacked injection mode. A peak distortion was observed during volume overloading, which may be due to the mixed-stream injection method.

Xiao–Jian–Zhong–Tang (XJZT) has the effect of warming the middle and tonifying the deficiency, easing the urgency and relieving pain according to the theory of traditional Chinese medicine (TCM), and is able to treat spleen deficiency type chronic atrophic gastritis (CAG). Metabolites of TCM in cecum contents are common metabolites of intestinal bacteria and hosts, which can reflect the metabolic status in disease states. The present work was performed to study the effect of XJZT against CAG coupled with the cecal metabolites analysis and bioinformatics. A total of nine prototypical components and 144 metabolites were firstly identified in the cecum metabolites of XJZT using ultra-high performance liquid chromatography added to the quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF/MS), which underwent the metabolism of oxidation, reduction, methylation, and glucuronic acid reaction Furthermore, different prototypical compounds might metabolize into identical metabolites in the presence of intestinal flora. Bioinformatics was further used to correlate these metabolites with the disease and intestinal flora. Components and targets were screened by Cytoscape, and molecular docking of key targets and core components showed good binding ability. This study provided important information for exploring the mechanism of TCM formulae.

Huperzine A is a reversible and selective cholinesterase inhibitor and has been approved for the treatment of Alzheimer's diseases. In this study, we developed a highly sensitive and specific ulta-high-performance liquid chromatography–tandem mass spectrometry method for the determination of Huperzine A in rat plasma. An aliquot of 50 μL of rat plasma sample was pretreated with 200 μL of acetonitrile-methanol (v/v; 1:1) containing 0.2% formic acid followed by solid phase extraction. The resulting sample was separated on a Waters ACQUITY BEH C₁₈ column using acetonitrile and water containing 0.2% formic acid as mobile phase, at a flow rate of 0.3 mL/min. Multiple-reaction monitoring (MRM) mode was used for quantitative analysis of Huperzine A in positive electrospray ionization. In the concentration range of 0.01–10 ng/mL, Huperzine A showed excellent linearity with correlation coefficient > 0.998. The intra- and inter-day RSD% were less than 9.7%, while the RE% ranged from −6.7% to 10.0%. The mean recovery was >84.5%. The validated method was demonstrated to be selective, sensitive, and reliable, which has been successfully applied to pharmacokinetic study of Huperzine A in rat plasma. Huperzine A displayed a long half-life in rat plasma and high oral bioavailability.

The efficacious treatment of muscle and joint pain relies heavily on etofenamate (ETO) and benzyl nicotinate (BN), which possess robust anti-inflammatory and pain-relieving properties when paired with methylparaben (MP) or benzyl alcohol (BA). In this study, we have established and validated innovative RP-UPLC methods for assessing ETO and BN in the presence of MP or BA in their dosage forms, employing eight green tools to evaluate their eco-friendliness and effectiveness. Reversed phase-ultra-performance liquid chromatography (RP-UPLC) technique employs a flow rate of 0.3 mL/min on Waters Acquity UPLC BEH Column (C18, 1.7 μm, 100 mm × 2.1 mm), detection at 254 nm using a photo diode array (PDA) detector and mobile phase of 0.05 M KH₂PO₄ buffer, acetonitrile, and methanol (50:15:35, v/v/v) adjusted pH 6.0 with 0.2% triethylamine. For ETO, BN, MP, and BA, the calibration curves were linear and ranged from 0.005 to 1.0, from 0.001 to 0.2, from 0.002 to 0.08, and from 0.0001 to 0.1 mg/mL, respectively. The correlation value was 0.9999, and the accuracy findings ranged from 98.81% to 100.56%. Consequently, the methodology has been successfully implemented in assay testing for the pharmaceuticals in the presence of the MP or BA, demonstrating the high selectivity of these approaches. The present study presents the Blue Applicability Grade Index (BAGI), an innovative approach that complements green metrics in practical white analytical chemistry. According to the International Council for Harmonisation (ICH) criteria, the procedures were effectively validated.

A liquid chromatography electrospray ionization tandem mass spectrometry method with amoxicillin-d₄ as the stable isotope-labeled internal standard for simultaneous quick detection of amoxicillin and clavulanic acid in human plasma was developed and validated. Chromatographic separations were performed on a Hedera ODS-2 column (2.1 × 150 mm, 5 μm). The mobile phases for gradient elution were aqueous solution containing 0.2% acetic acid (AA) (mobile phase A) together with organic phase solution (acetonitrile and methanol mixed solution, mobile phase B). Mass spectrometry was performed using negative electrospray ionization in multiple reaction monitoring mode. The target fragment ion pairs of amoxicillin, clavulanic acid and amoxicillin-d₄ were m/z 364.1 → 223.1, 198.1 → 135.9 and 368.1 → 227.1, respectively. The linear ranges of this method were 40–5,000 ng/ml for amoxicillin and 30–2,500 ng/ml for clavulanic acid, with coefficient of determination > 0.9900. This method validation included selectivity, standard curve, lower limit of quantitation, accuracy, precision, recovery, matrix effect (hemolytic matrix and hyperlipidemic matrix), carryover, stability, dilution reliability and incurred sample reanalysis study. A successful application of this method was realized in a pharmacokinetic study after administration of amoxicillin–clavulanic acid potassium granules.

This study presents a novel liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for quantifying cabotegravir (CAB) in rat plasma. A novel, sensitive, and rapid LC-MS/MS method has been developed and validated. Furthermore, protein precipitation technique allowed us to lowered the limit of quantification (LOQ) to nanogram levels, allowing detection of smaller CAB amounts in plasma samples. A review of scientific literature reveals that this method is superior than published methods in terms of runtime, sensitivity, wide linearity, and cost, using LC–MS/MS to quantify CAB in biological samples. CAB reached its maximum concentration (Cmax) of 78.401 μg/mL in rat plasma at 1.50 h (Tmax). Linearity was evaluated across 0.05–1000 μg/mL for CAB using five calibration curves with at least nine standards each with r² > 0.9997. The intra- and inter-day precision and accuracy results were below 15% and acceptable as per Food and Drug Administration (FDA) guidelines. Stability of compounds were established in a battery of stability studies, that is, benchtop, autosampler, and long-term storage stability as well as freeze thaw cycles. The validated method can be used as a routine method to support pharmacokinetic studies.

This study investigates the combination of FGFR inhibitor futibatinib (FTB) and MEK inhibitor binimetinib (BTB) for KRASmt NSCLC therapy. An analytical method was developed and validated for measuring FTB and BTB concentrations in rat plasma, adhering to USFDA guidelines. Using liquid–liquid extraction on 45-μL plasma samples, a 6.5-min run time was achieved. The linear calibration curve ranged from 2 to 100 ng/mL. Intra-day and inter-day accuracy ranged between 92.06% and 100.08%. Four blank injections post high-concentration samples resolved significant carryover. Extraction recoveries averaged 92.06% to 102.37% across concentrations. No significant endogenous interference was detected in blank plasma. The LLOQ for both drugs was 2.0 ng/mL. Selectivity, matrix effects, stability, and dilution integrity met the acceptance criteria. The method assessed FTB and BTB interaction potential in combination therapy at 5 mg/kg. The findings provide essential pharmacokinetics insights for future clinical trials.

Thirteen flavanone racemates were successfully separated using a Chiralpak® IA column and isopropanol-hexane (50:50, v/v). The mobile phase flow rate and detection wavelength were 0.5 mL/min and 254 nm. The retention times values ranged from 5.50 and 56.45 min. The values of the retention, separation, and resolution factors ranged from 0.63 to 21.67, 1.12 to 2.45, and 0.13 to 11.94. The docking binding energies ranged from −6.2 to −8.2 kcal/mol, showing enthalpy-determined host-guest complex formation. The molecular docking results and the experimental data were agreed well. The results showed that S-enantiomers had stronger bindings with chiral selectors compared to R-enantiomers. Consequently, the R-enantiomers eluted first followed by S-enantiomers. The reported method is highly useful to determine the enantiomeric composition of the reported flavanone in any sample.

This study validates a stability-indicating LC method for detecting organic impurities in the chlorzoxazone dosage form. Using a Waters X-Select R HSS T3 analytical column, mobile phase of it was made by mixing of water, methanol, and glacial acetic acid in the ratio of 700:300:10 (v/v/v). The drug product and drug substance were subjected to the stress conditions such as acid, base, oxidation, heat, and photolysis as per the recommendations of the International Conference on Harmonization (Q2) methodology. The study revealed the susceptibility of 4-chloro-2-aminophenol to alkaline environments, emphasizing peak homogeneity and stability. The method verification, per ICH guidelines and USP<1225>, established precision, specificity, linearity, accuracy, and robustness for quality control. The mean impurity recovery ranged from 95.5% to 105.2%, the correlation coefficient (r) was greater than 1.000, and the RSD values (n = 6) ranged from 0.6% to 5.1% across the LOQ–150% ranges. Full-factorial design tested final method conditions, evaluating multiple parameters concurrently. Graphical optimization within the design space defined strong method requirements, ensuring consistent and reliable outcomes. The study develops and validates chlorzoxazone stability-indicating methods, employing advanced statistical approaches like design of experiments and factorial design, with resilient conditions established through graphical optimization of the design space.