Publications by authors named "Mika Murabayashi"
Article Synopsis
- P-NMR is easier to analyze than H-NMR, making it simpler to identify target signals for quantitation.
- The study presents a method for determining the purity of brigatinib (BR), an organophosphorus compound, using quantitative P-NMR (P-qNMR) across multiple labs.
- Results showed that the purity of BR was 97.94 ± 0.69% with P-qNMR, closely matching the 97.26 ± 0.71% found using H-qNMR, suggesting P-qNMR is a viable alternative for measuring organophosphorus compounds.
Quantitative P-NMR for Purity Determination of Sofosbuvir and Method Validation.
Chem Pharm Bull (Tokyo)
December 2022
Article Synopsis
- The study examines the effectiveness of phosphorus quantitative NMR (P-qNMR) for measuring the purity of the drug sofosbuvir (SOF), as it offers clearer signals compared to hydrogen quantitative NMR (H-qNMR).
- Soxfabuvir's purity was found to be 100.63% via P-qNMR and 99.07% via H-qNMR using methanol-d, highlighting numerical discrepancies likely due to overlapping signals in H-qNMR.
- When switching to dimethyl sulfoxide-d (DMSO-d) as a solvent, P-qNMR yielded a SOF purity of 99.10%, which aligns closely with H
Recently, quantitative NMR (qNMR), especially H-qNMR, has been widely used to determine the absolute quantitative value of organic molecules. We previously reported an optimal and reproducible sample preparation method for H-qNMR. In the present study, we focused on a P-qNMR absolute determination method.
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- Quantitative NMR (qNMR) is used to establish the absolute quantitative value of standards for HPLC-based quantification, specifically for hygroscopic substances like saikosaponin a and indocyanine green (ICG).
- The study highlights the impact of humidity on the purity determination of ICG, noting that non-controlled humidity resulted in higher variation (86.12 ± 2.70%) and residual ethanol in the samples.
- Using a controlled humidity environment, the purity of ICG decreased variability (84.19 ± 0.47%), and employing a constant temperature and humidity box minimized variation further (82.26 ± 0.19%), suggesting its use for standard reference preparation in JP
Context: Drug-induced phospholipidosis is one of the significant concerns in drug development, especially in safety assessment and noninvasive diagnostic tool is highly desirable.
Objective: The objective of this study is to explored novel biomarkers for phospholipidosis using a metabolomic approach.
Method: NMR spectrometry and LC/MS/MS analyses were applied to urine and plasma of rats administrated cationic amphiphilic drugs.
Method development and validation for simultaneous quantitation of endogenous hippuric acid and phenylacetylglycine in rat urine using liquid chromatography coupled with electrospray ionization tandem mass spectrometry.
J Chromatogr B Analyt Technol Biomed Life Sci
November 2016
Urinary hippuric acid (HA) and phenylacetylglycine (PAG) are biomarker candidates for drug-induced phospholipidosis (PLD). To confirm their utility in preclinical and clinical settings, it is essential to develop and validate their quantification method in advance. In this study, we have applied liquid chromatography-tandem mass spectrometry (LC/MS/MS) for simultaneous quantification of HA and PAG in rat urine, and matrix based ion suppression was assessed by post-column infusion assay.
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