Quality Assurance

Honso’s GMP pharmaceutical facilities in Japan offer unrivaled high standards, from selection of the highest grade materials to perfection of proprietary processing techniques that ensure maximum quality, efficacy and safety.  Every lot of the Honso^® Kampo product is routinely tested by its Quality Control Department. They are tested for key herbal constituents, heavy metals, purity, and microbial content to eliminate any contaminant. This is the most rigorous way to maintain consistency of quality from batch to batch each time. For detail, read the interview with Dr. Dan Wen.

Strict Quality Control Procedures

Japan’s most important contribution to Oriental herbal medicine, besides the tremendous amounts of research, is what was called “semi-standardization” of herbal mixtures. It is easy nowadays to standardize a single botanical such as assaying milk thistle for silymarin or Ma Huang for ephedrine. However, it is difficult to assay and therefore standardize a mixture of several or sometimes 10 to 20 herbs. Most herbal manufacturers only control the weight of each ingredient that goes into a formula before extraction. Some control quality qualitatively by thin layer chromatography (TLC), which only assures that the required herb is in the product. In Japan, all prescription herbal formulas are required by the Ministry of Health and Welfare to both qualitatively and quantitatively assay their finished products.

At Honso, the quality control of a finished herbal formula is performed under the scrutiny of the Ministry of Health and Welfare at two levels on every lot: first assay each individual herb qualitatively by TLC, and then measure at least two active constituents quantitatively by HPLC. For example, Minor Bupleurum Formula (sho-saiko-to, H09) is processed as follows:

TLC testing: to identify Bupleurum, Ginger, Scutellaria, Jujube, Ginseng, and Glycyrrhiza. HPLC testing: specification is as such: 24.7-46.0 mg/day of Glycyrrhizin, 110.6-205.6 mg/day of Baicalin, and 6.5-19.7 mg/day of Saikosaponin. Other testing is routinely performed on each lot according to the Japanese Pharmacopoeia, including heavy metals, arsenic, and water content and microbiological tests.

According to Japanese Importing GMP (iGMP) guideline, other tests are performed to assurance consistency of herbal species. First Honso identify where the plant are grown and harvested and chooses the specific method of preparation based on tissue and cell morphology, and differentiates it from similar raw herbs. Then Honso performs the extract content test to determine the content of ingredients soluble in water, absolute ethanol or ether as overall content of the active ingredients. The loss-of-drying test is performed 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. The acid-insoluble ash is tested to identify the amount of earth and sand attached to the raw herbs. 

Consistency in Manufacturing of Kampo Products

Kampo medicine has been passed down through generations the way Chinese medicine has been. The most common method of herbal processing is water decoction of sliced raw herbs. So modern herbal industries in Japan and China have used a similar process for the mass production of herb formulas. The process usually includes: slicing, extraction, solid-liquid separation, condensation, drying, and granulation. Granules are the most commonly accepted way for herbal formulas in Japan.

Raw herbs are sliced to predetermined sizes weighed and compounded in quantities depending on what is needed for particular formulas. In the extraction process, active constituents are extracted from raw herbs as herbalists have traditionally done, by water decoction. A heat control system is used capable of precisely controlling a boiling condition, for up to several hundred kilograms of herbs per run. Raw herbs are heated to 100 °C with water 20 times in volume and then extracted for 50 minutes after the temperature is reached.

The solid-liquid separation separates the solid residue of raw herbs from the liquid after extraction by first 80 and then 200 mesh sieves according to the Japanese industry standard. In the condensation process, water is purged off the extracted liquid before the liquid goes into the drying process. 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.

The spray-drying process is the process of dehydrating the condensed liquid for production of dry extract powder. 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 to form the final granules (for detail, read "An Interview with the President").

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