２．Increased transparency of crude drug quality and the development of quality evaluation technologiesDetails

Background

The Pharmacy of the Kitasato University Oriental Medicine Research Center mainly prepares decoctions according to the Japanese Kampo theory. Kampo medicine was traditionally practiced in Japan and was based on ancient Chinese medicine. In Japan, Japanese wild related crude drugs (herbal medicines) similar to Chinese herbal medicines have been utilized when Chinese herbal medicines are unvailable. In the past, the medicinal plants that produce herbal medicines were cultivated on a large scale in Japan, and some herbal medicines were exported overseas. In addition, many examples of treatments with Kampo medicine have been accumulated by Japanese people that were composed of herbal medicinal products. However, due to the decline in the number of medicinal plants native to Japan and the time and effort required to produce herbal medicines, crude drugs produced in Japan, are being replaced by cheaper Chinese herbal medicines. Furthermore, in recent years, the price of Chinese herbal medicines has been increasing due to rising labor costs and the growing demand for crude drugs in China. Therefore, the importance of promoting the production of herbal medicines in Japan is being widely recognized.
Quality control of crude drugs plays an important role in the promotion of crude drug production in Japan. Since crude drugs are natural products, the quality and form of crude drugs vary depending on the place of origin, weather, growth, cultivation method, and processing method. In addition, it is difficult to identify the quality of a new production area. Because crude drugs are natural products and contain many components, it is not reasonable to analyze only one component when examining their chemical properties and clinical effects. Therefore, a comprehensive analysis of the chemical components is necessary. Recent advances in chemical analysis techniques have enabled the development of new technologies for comprehensive analyses.
PCA is a visualization tool that facilitates the comparison between samples that contain many elements. We used principal component analysis (PCA) as a statistical technique for exhaustive chemical analysis of samples that contain numerous elements; it allows the mapping of samples with similar patterns closely in a plot to reflect the similarities and differences between samples. We have used this approach to produce a "quality control map for crude drugs" that can be used for individual crude drugs. In this process, we conducted experiments using 1H-nuclear magnetic resonance (1H-NMR), which is a chemical analysis technique that enables the simple generation of highly reproducible measurements (Figure 1).

Figure 1

Overview

The purpose of this study was to objectify and quantify the empirical knowledge on the evaluation of the quality of crude drugs and establish a quality control system for crude drugs with high reproducibility in a relatively short time using a rapid method.
We currently focused on 33 frequently prescribed combinations of 46 crude drug products, with the support of the Division of Pharmacognosy, Phytochemistry and Narcotics of the National Institute of Health Sciences, the Research Institute for Medicinal Plant Resources of the National Institutes of Biomedical Innovation, Health and Nutrition, the Tokyo Crude Drugs Association, and many other agencies and corporations. We have successfully produced a "quality control map for crude drugs" for 46 crude drug products, as shown in Figure 2.

Figure 2