Comparison of granules for prescription and classical decoctions by high-performance thin-layer chromatography-fingerprint analysis

Objective: The so-called granules for prescription have been developed about 20 years ago as a new form of modernizing and simplification of the classical decoction common in Traditional Chinese Medicine (TCM) practice. Due to actual problems in Germany/Europe, which are caused by the lack of quality monographs and judicial classification of granules for prescription, the aim of the study was a comparison of the chemical composition of commercial granules versus decoctions. Taking an example, decoctions, commercial granules, and organic extracts of two well-established TCM herbal drugs, Scrophulariae Radix and Xanthii Fructus, were examined in their specific composition. Methods: Using high-performance thin-layer chromatography (HPTLC) for fingerprint analysis of different batches of herbal drugs and samples from various suppliers of Xanthii Fructus and Scrophulariae Radix were critically examined. The decoctions were prepared according to traditional rules, while the granules were dissolved in water in accordance with actual regulations. Furthermore, organic extracts of the plant material were examined and compared with aqueous extracts. Results: It could be demonstrated, that in some cases, there are remarkable differences in the specific composition between granules from different suppliers, the classical aqueous decoction and the organic extract used for the HPTLC fingerprinting. On the other hand, few examples exist for good comparability of decoctions and commercial granules. Conclusion: After critical evaluation of the above results, it can be questioned, if there is a so-called phytoequivalence between decoctions and commercial granules for prescription used in TCM practice.