Herbal Medicine

Global Trends in Granule Use

By August 15, 2014 July 27th, 2020 No Comments

By Eric Brand

 

The creation of concentrated extract powders represents one of the most important developments in the history of Chinese herbal medicine.  As technology has advanced, Chinese herbalists increasingly find themselves armed with a vast arsenal of convenient preparations that bring centuries of formulas and thousands of cooking hours into a space the size of a small closet.

Leading this revolution of concentrated powders, liquids, and gelcaps are the “granules,” which are concentrated dry extract powders that essentially place a full traditional pharmacy at the practitioner’s fingertips.  The versatility of granules has preserved some aspects of traditional methods while simultaneously inspiring dramatic changes of approach in Asia, and their convenience is quickly making them the most prominent method of herbal medicine delivery in the West.

Japanese Roots

 

Granule technology was originally pioneered in Japan, where it was created for Japanese Kampo.  In Japan, most use of granules is based upon either biomedical or traditional applications of classical formulas, which are often used in an unmodified form.  The vast majority of the formulas used in Japanese Kampo were created prior to the Song dynasty in China (around 960 CE), and formulas from the Shang Han Lun and Jin Gui Yao Lue are particularly prominent in modern clinical use.  Practitioners rarely build formulas from single ingredients, instead preferring to employ whole formulas or combinations of formulas.  While few Westerners have studied Japanese Kampo itself at depth, the technology that was created to maximize the Kampo approach has impacted Western practitioners tremendously.

From Japan, the technology spread first to Taiwan.  Granules have become deeply integrated into healthcare in Taiwan over the past 30 years, and their prominence there has created an entirely new style of Chinese medicine.  Indeed, many doctors feel that the most distinctive feature of Chinese medicine in Taiwan is its use of granules.  This development was largely stimulated by the convenience of granules for patients, along with the fact that Taiwanese government insurance covers granule extracts exclusively when it comes to Chinese herbal medicine coverage.  Granules are desirable for large scale healthcare because they are well-regulated and hygienic, and they are ideal for research because batches are consistent and traceable.  Significantly, Taiwanese patients pay very little out of pocket for granules yet have to pay a fair sum out of pocket for raw herbs; this has created an entire culture of granule use, with the vast majority of patients using herbs in a concentrated extract form.

Taiwanese Methods

The Taiwanese method of using granules is relatively distinct because whole formulas are commonly combined together.  With a repertoire of over 400 compound formulas on the shelf, Taiwanese doctors build complex combinations that boggle the young student mind, yet there is nothing haphazard about the construction of a well-crafted Taiwanese style formula if one understands the approach.  Good doctors in Taiwan typically have a broad range of formula ingredients mastered, with a well-developed ability to see the relationships, similarities, and differences in each.  A core formula at a higher dose typically stands out at the center of the prescription, but instead of adding in just a few single herbs to accentuate certain directions, whole formulas may be added in.  Here the formulas are used as a single principle, much as many of us add a single herb.

There are several reasons why compounding whole formulas together has become popular in Taiwan.  Given the Japanese origin of the granule technology and the prominence of combining classical formulas in Japan, it seems reasonable to think that some of the initial inspiration for creating a wide range of whole formulas and combining them together may have been rooted in the technology’s Japanese roots.  However, the most important guiding factor today is the widespread belief in Taiwan that formulas that are cooked together are clinically superior to formulas that are created from scratch by combining single herb extracts.

Indeed, there are measurable differences in the final chemistry of the end product when medicinals are cooked together versus when they are combined from single extracts.  Taiwanese doctors point to these differences and often strongly believe that the results of using whole formulas surpass the results of combining singles from scratch.  While there have been studies in China that show no statistical differences between the clinical results of combining singles from scratch in comparison with whole formulas that have been cooked together, the vast majority of doctors in Taiwan prefer to use formulas that have been cooked together.

In addition to starting with whole formulas (often compounding two or three whole formulas together), Taiwanese doctors commonly add single herb extracts when customizing the prescription.  Their insurance system pays for granules up to a dose of 6.0g, and the typical 6.0g dose is usually given three times per day for a total of 18g of concentrated extract powder per day.  While the precise extraction ratios for each product are clearly stated on Taiwanese granule labels, most doctors think less in terms of calculating extraction ratios and replicating raw herb doses by weight, and focus more on the ratio of herbs and formulas within the daily target dose of 18g/day.

The dosage used by most doctors in Taiwan tends to fluctuate between 12–18g/day, with 18g being the most common for adults.  Each granule product in Taiwan varies somewhat in terms of its concentration ratio, but a quick mathematical calculation shows that this concentrated powder dose is slightly lower than the typical daily dose given by Taiwanese doctors when they are dispensing raw herbs (often over 100g/day of crude medicinals).  Despite this somewhat lower dose, granules are extracted more efficiently than herbs cooked at home, so it is reasonable to assume that they are at least slightly more potent than the equivalent amount of crude herbs.  Furthermore, the use of whole formulas instead of just single herbs makes it slightly less of a straight mathematical equation, as the heat-clearing effect of a whole formula like huang lian jie du tang (Coptis Toxin-Resolving Decoction) is more powerful than the equivalent weight of singles like huang lian (coptis) or zhi zi (gardenia) alone.

Although most of the granule products in use in America are made in Taiwan, thus far relatively few practitioners are well-informed about the Taiwanese methods of using granules clinically.  Because granules dominate the insurance-based healthcare system in Taiwan, doctors there have amassed a tremendous amount of experience with issues such as dosage and formula combining.  However, while most of us here in the US use their products, few of us use their methods and dose ranges, making their results more difficult to replicate.

Common Approaches in Mainland China

In contrast to Taiwan, doctors in mainland China tend to combine whole formulas together much less, and primarily build formulas from scratch in a process identical to a normal raw decoction.  While Taiwan has created a virtually new method of using herbal medicine based on their granule approach, granules in the mainland are largely an extension of the standard method of formula composition.  In mainland China, whole formulas are less commonly available in a granule form, so nearly all prescriptions are made by combining singles.  Rather than determining dose based upon a standard dose range of total extract powder, the dose is determined mathematically based on the raw herbal prescription.

While there are differences between mainland China and Taiwan in terms of their prescription composition when using granules, the biggest differences actually lie in their respective packaging and extraction technology.  In mainland China, granules are often made without filler, and are packaged in single dose foil packs.  In Taiwan, granules are made into a smooth flowing powder that is dispensed from small plastic bottles.

Granules that are made without filler must be packaged immediately to prevent clumping, which occurs rapidly if filler-free extract powder is exposed to air.  The most common packaging method used in mainland China is a single dose foil pack that contains the concentrated equivalent of a standard daily dose of a given raw herb.  Each herb has the potential to achieve a slightly different concentration, so the concentration ratio of each product (and the corresponding dose weight) varies.  For an herb such as yan hu suo (corydalis), a 10:1 extract can be achieved, and the foil pack will contain 1g of extract because 10g of the raw product is used as an average daily dose.  Another herb such as pu gong ying (dandelion) can only reach a 7.5:1 concentration, so a daily dose foil pack of pu gong ying contains 2g of extract, which is equivalent to 15g of the raw herb, again a typical daily dose.

The mainland Chinese method of using foil packs is convenient because a scale is not required, the formula can be easily modified, and ingredients can be subtracted if side-effects develop.  However, the foil packs are slightly cumbersome because many packs must be opened with each daily dose, and there is more disposable waste associated with the foil packs.

As an alternative to the foil packs, some Chinese manufacturers have begun to produce products that dilute the pure concentrate with dextrin so that an even 5:1 consistency can be achieved.  This allows the product to be exposed to air and stored in plastic bottles like the Taiwanese products.

Similarities and Differences in Technology

Both mainland Chinese granules and granules made in Taiwan share many basic characteristics.  Reputable companies all capture and reintroduce essential oils, determine species identity with liquid chromatography, and evaluate potency by assessing marker chemicals in both the raw material and the finished product.  The temperature is controlled, and the ideal concentration ratio, water quantity, and cooking duration are determined by researching each product.  Batch testing assesses the final product to ensure that heavy metals, bacteria, and fungi are all absent, and most companies test the dissolution time in water.

However, despite these common features, significant differences remain between the technology used in mainland China and Taiwan.  In Taiwan, the herbal concentrate is reduced under a vacuum or forced air and low temperatures, and it is reduced to thick, viscous syrup that is then sprayed onto a carrier.  The carrier is typically either pharmaceutical starch or finely ground crude herbs.  Each herb achieves a different concentration ratio depending on how water soluble it is, as well as how sticky and rich it is by nature; these factors play a role in determining how much material can be extracted, and also influence the quantity of filler required to make the powder flow evenly.

By contrast, the mainland Chinese products are made into a dry extract without filler or with only a small amount of dextrin, and are immediately packaged in a sealed foil pack.  Each foil pack contains the equivalent of a standard daily dose of the crude medicinal.  This method does not allow for smooth flowing bulk powders that can be exposed to air for prolonged periods, so it is not suitable for the style of product required for the Taiwanese prescribing method.  However, it is suitable for the mainland Chinese method of simply using concentrated powders to give a daily dose that equates to the normal raw decoction dose, and the foil packaging allows it to be conveniently dispensed.

Both the mainland and Taiwanese technologies offer unique advantages and disadvantages, but they produce slightly different final products.  Taiwanese powders are often made into a relatively fine powder (xi fen), while mainland Chinese powders are often made into a slightly larger granule (ke li) when they are sold in the 5:1 state.  The mainland products are often able to achieve a higher and more consistent concentration ratio and tend to have less filler, but the Taiwanese products often tend to have a slightly stronger odor.  Additionally, the method of processing mineral medicinals often varies between the two regions, and the availability of herbs in a variety of pao zhi forms varies as well.  Mainland China has a slightly wider selection of herbs with different types of pao zhi on the market, but Taiwan has a wider range of pre-made classical formulas available.

All of these factors illustrate the fact that the modern granule landscape is relatively diverse.  Multiple styles abound, both in terms of formula composition as well as manufacturing styles, and each practitioner has a wide range of choice in determining which products and approaches are best for their clinical needs.  Unfortunately, at present many Western practitioners have not deeply investigated the Asian trends in granule prescribing, and often remain uncertain on issues such as dosage calculation.  Few practitioners realize that different technological methods are used in mainland China and Taiwan, and often fail to take these differences into account when determining dosage.  As we move into a direction of clearer product labeling and increased cultural exchange, hopefully the West will begin to acquire more of the experience that our Asian colleagues have amassed in this fascinating field.  Given the fact that granules are quickly becoming the most common form of herbal medicine in the Western clinic, it appears essential that we strive to better understand these products in terms of their dosage and clinical applications.


Eric Brand graduated from the Pacific College of Oriental Medicine (PCOM) and has extensive experience studying in mainland China and Taiwan.  Fluent in Chinese language, he completed a prolonged internship at Chang Gung Memorial Hospital in Taiwan and has participated in numerous projects related to Chinese medicine translation, herbal research, and TCM politics.  He is author of A Clinician’s Guide to the Use of Granule Extracts, co-author of the Concise Chinese Materia Medica, and has edited a variety of modern and classical texts.

Eric has a passion for Chinese herbal pharmacy, and he travels extensively to study with experts in the field of herbal authentication and quality discernment.  He is founder and owner of Legendary Herbs.

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