Comparative analysis of 30 East Asian traditional medicine formulations revealed the applicability of 1H NMR spectroscopy in quality control

Multi-herbal formulations in East Asian traditional medicine have long played an important role in disease treatment and modern drug discovery. Despite extensive efforts toward standardization, quality control remains challenging due to their chemical complexity and richness in polar metabolites, which complicate chromatography-based methods. Nuclear Magnetic Resonance (NMR) spectroscopy offers an alternative solution; however, previous studies have mainly focused on single formulations, with limited systematic analysis across multiple formulations. This study explores the applicability of ¹H NMR spectroscopy for quality control in East Asian traditional medicine products by analyzing 86 batch samples from 30 formulations, manufactured in a GMP-certified facility. Pearson correlation efficients between binned spectra were calculated to evaluate both batch-to-batch and formulation-to-formulation similarities. Batch-to-batch correlations were consistently high (r > 0.99), indicating excellent reproducibility. In contrast, formulation-to-formulation correlations ranged from 0.72 to 1.00, largely influenced by saccharide abundance. Additionally, three major specialized metabolites—paeoniflorin, naringin, and baicalin—were identified based on their characteristic proton signals, and their presence correlated with the herbal composition of each formulation. These findings highlight the potential of ¹H NMR analysis as an effective solution for the quality control of traditional medicines, addressing the challenges posed by their chemical complexity while ensuring consistency and providing detailed insights into metabolite variations among formulations.