Part I     Part II    Part III

JG: Could you please elaborate on the Japanese industry standard for manufacturing processes in creating herbal granulated powders?

DW: Certainly. Crude extract powder is manufactured in five processes. These are: 1) slicing and compounding; 2) extraction; 3) solid-liquid separation; 4) condensation; and 5) drying.

JG: OK. How exactly do you accomplish slicing and compounding?

DW: Raw herbs what we call "crude drugs" are sliced to predetermined sizes weighed and compounded in quantities depending on what is needed for particular formulas. Since the raw herbs differ from one to another in shape, size and the way they should be sliced, particular slicing methods are selected according to the characteristics of raw herbs involved. We weigh and compound the raw herbs in quantities corresponding to specified production units in accordance with the formula’s blending ratio, which is how many “parts” each herb gets in a particular formula.

JG: All right. And the extraction process itself?

DW: In the extraction process, active constituents are extracted from raw herbs as herbalists have traditionally done, by water decoction. As the extraction apparatus we use a heat control system capable of precisely controlling a boiling condition, for up to several hundred kilograms of herbs per run. We add water 20 times the weight of the raw herbs and heat them to 100 °C in less than 20 minutes while stirring, and we then extract the crude solution for 50 minutes after this temperature is reached.

JG: OK. What’s next?

DW: Then there’s the solid-liquid separation. This process separates the solid residue of raw herbs from the liquid after extraction. A series of operations ranging from water purging, heating, extraction and separation are sequence-controlled with the aid of system features to predetermine operating conditions and monitor performance to assure each run is the same. We separate fluid fraction from solid fraction by first 80 and then 200 mesh sieves per the Japanese industry standard.

JG: So the next step is condensation, I believe?

DW: Yes. In the condensation process, water is purged off the extracted liquid before the liquid goes into the drying process. In the case of, for example, Xiao Chai Hu Tang (Sho-Saiko-To in Japanese), a low temperature vacuum extraction method has been adopted. This method can evaporate water at low temperatures of 30 to 40 °C. and minimize thermal deterioration of extracted liquid constituents. We vacuum concentrate the extract to a five-percent volume before spray-drying.

JG: And the drying process?

DW: This is the process of dehydrating the condensed liquid for production of dry extract powder. The spray-drying machine incorporates high-tech applied functions because Sho-Saiko-To Extract in its liquid phase is like slurry, and dry extract powder is highly moisture-absorbent.

JG: But you still haven’t created granules yet, have you?

DW: No, that’s the final part. First we compressively mold and crush the dry extract powder, and then we fill and pack the product containers.

JG: Please elaborate on granulation.

DW: In the compressive molding and crushing process, dry extract powder is blended with a binder or excipient, usually rice starch and crystalline cellulose, then temporarily compression-molded and finally crushed and filtered for uniform size. This process uses a special molding machine which provides uniform, stable and quick compression-molding and a crusher capable of crushing the moldings into a desired particle size. Lastly, we use an automatic weighing machine to assure filling the packets in exact quantities.

JG: This all sounds pretty thorough, but what about the quality control you’re so proud of? Could you walk us through the whole process a bit more precisely?

DW: Well, I believe what you want is this. First the raw herbs are quality checked. Then they are unpacked, graded and selected for use, then quality checked again. The herbs are then sliced and again quality checked. After that, the sliced herbs are weighed and mixed, then extracted, filtered and separated, and another quality check is performed. Following the next step, condensation, a quality check is again performed. Then the herbs are spray-dried and formed into crude extract powder, and a quality check is done. Then the herbs are sieved and weighed, blended and granulated, and the last quality check is done. The granules are divided into proper doses, and filling and packing create the final product.

JG: OK, all these quality checks. Please elaborate. How do you quality check the raw herbs when they first come in?

DW: According to Japanese Importing GMP (IGMP) guideline, first we make sure we have what we ordered by identifying the description of the raw herbs based on characteristic appearance, taste, odor and color. We identify where the plant was grown and harvested and choose the specific method of preparation based on tissue and cell morphology, and differentiate it from similar raw herbs.

JG: This involves laboratory testing, doesn’t it?

DW: Yes. The primary test is for key compounds identification. Bio-markers such as the alkaloids, saponins and flavonoids in Sho-Saiko-To show specific spots through Thin-Layer Chromatography (TLC) testing. Then we assay the exact content of bio-markers in raw herbs using High-Performance Liquid Chromatography (HPLC). In the case of Sho-Saiko-To we assay for saikosaponin a and d, baicalin and glycyrrhizin. Then we perform what we call the extract content test to determine the content of ingredients soluble in water, absolute ethanol or ether as overall content of the active ingredients. This test is requested by the Japanese Ministry of Health and Welfare. Then we perform the loss-of-drying test to determine water content in the raw herbs as confirmation of proper production procedures and storage stability. A total ash test is done to determine inorganic content in the raw herbs. Then we do an acid-insoluble ash test to identify the amount of earth and sand attached to the raw herbs. Finally we perform a test to determine the content of essential oils in the raw herbs.

JG: OK, Dan, I think that’s all the time we have now. Next time I want to learn more about quality checking after the actual product preparation begins, and I want to begin talking about the controversial subject of standardization.

DW: I look forward to it.

Readers, we will be continuing this series of interviews in the next few issues of Acupuncture Today. if you have questions for Dr. Wen, please send your e-mails to Joseph Garner at acugrpaz@aol.com.

Copyright © Honso USA, Inc.