Quick and easy preparation method for decoction of Kampo formula inspired by the method of boiling powdered crude drugs in the Song period of China

Abstract

Aim:For the purpose of reducing both the consumption of crude drug resources and patient burden in preparing the decoctions, we developed a new preparation method for the decoctions of Kampo formula: immersion of powdered crude drugs in hot water (IPCD method), inspired by a method of decoction that was widely used in the Song period of China. Methods: Ephedra herb (terrestrial stem of Ephedra sinica), scutellaria root (root of Scutellaria baicalensis), and Kampo formulas that contain several crude drugs including ephedra herb and scutellaria root were powdered, and then immersed in hot water to extract the ingredients. The residue was filtered out using a commercially available tea server. The contents of marker compounds in the decoctions were measured. Results: Using the IPCD method, the amounts of marker compounds from ephedra herb and scutellaria root transferred to hot water exceeded by 1.3-1.4-fold that obtained by the standard method of decocting the same amounts of cut crude drugs for >30 min. The amount of transferred marker compounds reached a plateau within 4 min after the beginning of immersion, suggesting that only 4 min of immersion is sufficient for the IPCD method. The sludge residue of powdered crude drug produced by immersion could be easily filtered with a commercially available tea server. Conclusion: Using this method, the same or greater amounts of marker compounds were transferred in the decoctions in a much shorter time with lower consumption of crude drugs than with the usual decoction method.

The acrid raphides in tuberous root of Pinellia ternata have lipophilic character and are specifically denatured by ginger extract

“…The IPCD method was developed for easier preparation of Kampo decoctions. In the IPCD method, the crude drugs are powdered and mixed vigorously with boiled water then filtered after 4 min [ 11 ]. This method is convenient; however, the short heating time results in intense residual acridity of the unprocessed Pinellia Tuber, which is a major problem.…”

“…Hangekoubokuto (banxiahoupotang) immersion was prepared using the immersion of powdered crude drugs (IPCD) method [ 11 ]. Pinellia Tuber (6.0 g), Poria (5.0 g), Magnolia Bark (3.0 g), Perillae Herba (2.0 g), and dried Ginger (1.0 g) were mixed and milled for 1 min.…”

Quick and easy preparation method for Kampo formula decoctions (part 4): IPCD method for rhubarb and aconite root

“…When unprocessed aconite root was extracted using purified water, the amount of diester alkaloids in the IPCD immersion was approximately ninefold that in the conventional decoction. The ratio of the increase was much larger than that for the non‐volatile marker compounds of crude drugs previously reported . Also, the amount of benzoylemesaconine, the hydrolysate of mesaconitine, was significantly lower in the IPCD immersion compared with conventional decoction.…”

“…We developed the immersing powdered crude drugs (IPCD) method with a view to shortening the preparation time. We have already shown that even better extraction efficiency is obtained within only 4 min of easy incubation in the IPCD method than by 30 min of conventional decoction . It has been said, however, that 30 min of boiling is required not only for good extraction efficiency but also to reduce the toxicity of crude drugs with strong physiological activity .…”

Quick and easy preparation method for decoctions of kampo formula (part 3): Extraction efficiency of the IPCD method for volatile compounds

“…As reported before, we have developed a new method of preparing decoctions by immersing powdered crude drugs in hot water without boiling, named the immersing powdered crude drugs (IPCD) method. Despite its quickness, the extraction efficiency of IPCD is slightly higher than that of the conventional decoction method and as a result of the shorter period of heat, a higher efficiency is expected with regard to the volatile compounds from crude drugs. In this study, the decoctions made from cinnamon bark and perilla herb using the IPCD method were more than twice as rich in the volatile marker compounds compared with conventional decoctions.…”