Part One: Granules in Asia
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. Concentrated dry extract powders (“granules”) essentially place a full traditional pharmacy at the practitioner’s fingertips. Granules preserve the traditional methods of Chinese medicine while allowing practitioners to give patients a convenient option for herbal therapy. Their safety, efficacy, and popularity are well-established, and granules are quickly becoming the most prominent delivery form of Chinese herbal medicine 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.
Granules 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 Granule 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 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.
Part Two: Korean Extraction Trends
In Korea, the most prominent method of herbal extraction relies upon small, pressure-based extraction machines. These “home extractors” are widespread in Korea, and they are a Korean invention that has had a dramatic effect on Chinese medicine worldwide. Their utility has caused them to spread outside of Korea, where they now dominate the landscape of hospitals and pharmacies throughout mainland China. Most of these extractors are essentially customized stainless steel pressure cookers, and they are generally paired with a packaging machine that dispenses the decoction into a durable, heat-stable plastic pouch. Korean-style extractors are currently in more widespread use than granules in both China and Korea.
Pressurized Korean extractors are essentially a home model of the pressurized steel extractors used in the manufacturing of granules. They can typically cook 5—30 packs of raw herbs per batch, and have been shown to significantly surpass home decoctions in the extraction of a variety of herbal constituents. The decoction is packaged without air so it has a relatively long shelf life even without refrigeration. In Korea, many patients regularly take supplementing decoctions in this form, and many pharmacies and even grocery stores sell pouches of ginseng and velvet antler extracts. Practitioners often prescribe a formula for several weeks at a time, and this delivery form is ideal for these customized, high-potency, long-term formulas. Because extractors can essentially make raw herbs convenient for patients, the corresponding formula composition style tends to parallel traditional herbal formulation approaches.
Generally, this is an excellent system. Prescriptions can be customized from raw herbs, and the traditional decoction process can be replicated with significantly less labor. Patients receive their decoction in single-dose, durable, heat-resistant plastic pouches that can be easily transported, re-heated, and consumed as needed. The pressurized cooking system allows for an extract that surpasses the traditional home decoction in terms of potency and efficiency, and the process reduces the human error of home decoctions in addition to providing convenience.
The efficacy of these home extraction machines has been well-demonstrated, as literally millions of doses have taken by patients in mainland China and Korea using this method. However, despite their ease of use and efficient extraction capacity, the home extractors do suffer from a few limitations that are not shared by the commercial machines used to make granule extracts.
Commercial Granule Technology vs. Korean Pressurized Extractors
Korean extractors allow private practitioners and clinics to make customized formulas with greater potency than raw formulas. They are easy to use and the medicinals are able to cook together, which many practitioners regard as an advantage over mixing dried individual extracts. Control over temperature and cooking duration makes extractors easy to use, and their comparatively small capacity makes them versatile for customized formulas. Additionally, extractors are commonly used by hospitals or clinics that maintain secrecy over formula ingredients; for example, I studied at a hospital in Taiwan that had proprietary research formulas cooked in Korean extractors so that the staff could not leak information about the formulas under investigation.
Nonetheless, home extraction machines pose a challenge with retention of essential oils, whereas commercial operations typically have a more sophisticated method of capturing the oils and reintroducing them into the final product. While a few of the most expensive home extractors do have an added unit to capture essential oils, most of the home extractors do not. Instead, the oils can be captured by allowing the decoction to slowly cool without opening the pressure valve, but allowing the decoction to cool instead of packaging it immediately can potentially affect the shelf life and hygiene of the decoction. Furthermore, the pressure created in the extractor is usually used to effortlessly move the liquid from the extractor to the packaging machine after the decoction is finished. During this transfer to the packaging machine, steam is lost and some of the essential oils may dissipate. For this reason, home extraction machines ideally require one to cook delicate aromatic medicinals separately on the stove, and the short stovetop decoction is added to the packaging machine at the end. This takes extra effort and is often skipped, so home extractors often lose some essential oil in comparison to commercial operations that use a combination of pressure cooking and essential oil capture.
Temperature is another variable that should be optimized and controlled when making extracts. When water is heated under pressure, its boiling point can rise beyond 100 degrees Celsius (212 F). This increase in temperature may offer benefits such as increased solubility of active compounds; however, it does introduce an unknown variable into the equation, as historically the decoctions used were only able to extract whatever constituents came out at the natural boiling temperature of water.
The temperature of the water can be controlled in both small extractors and large-scale commercial pressure cookers. However, in a small extractor, the transfer of the decoction from the pressure cooking machine to the packaging machine is best achieved under a significant amount of pressure. This ideal pressure is typically achieved by bringing the water temperature up to 120 C (248 F) before packaging the decoction. The high temperature and pressure creates a very hygienic and potent extract, but the uniform use of high temperature extraction for all medicinals is common when using small extractors. By contrast, large commercial producers can research the optimal cooking temperature of individual medicinals; the extraction temperature can be better controlled for each individual product, and usually the liquid leaves the sealed pressure cooking container with simple gravity rather than by releasing pressure, so high temperatures and high pressure are not required (the receiving container is usually below the cooking container in a factory, whereas the packaging machine of a home unit is usually above the cooking machine, so it is requires pressure to push the liquid uphill).
Cooking duration is also relatively poorly controlled in a home extractor when compared to the commercial process. For example, when cooking da huang (Radix et Rhizoma Rhei), a short cooking time will produce a potent purgative effect, while a prolonged cooking time will reduce its purgative effect. The short cooking can be achieved by the factory by using an abbreviated cooking time, but the home extractor requires the “add at the end” (hou xia) medicinals to be cooked separately on the stove and added in at the end. The medicinals cooked in a home extractor are all generally cooked for a similar duration of time, because it takes about 30-40 minutes of cooking at peak temperature to build the ideal pressure required to move the liquid into the packaging machine.
Additionally, measurement is somewhat more precise when using commercial extracts instead of small extractors. Small extractors can control the amount of decoction dispensed per pouch, and it is generally quite easy to make the doses per pouch appropriate for each patient. While not lacking in clinical efficacy or ease of use, the home extractors are not able to achieve quite the same mathematical precision that one can achieve when using a precisely measured and openly labeled commercial extract. This degree of precision may not be necessary in clinic, but it is advantageous for easy calculations (or legal cases).
Unfortunately, the litigious nature of American society has hampered the market penetration of home extraction machines in the United States. Most practitioners are unclear exactly how the law classifies an extract for a patient that is cooked in the practitioner’s clinic. Does it fall under a food preparation license? Is it a dietary supplement, a tea? Does it need to be GMP? Clearly there is virtually no enforcement, no massive push by the FDA to crack down on small-scale licensed practitioners cooking up formulas for patients. Yet despite the apparent lack of lawsuits, many practitioners remain reticent to cook their own formulas in their office. The labor of cooking the herbs and cleaning the machines, coupled with the gray area of licenses and liability has caused this huge global TCM trend of home extractors to go largely untapped here in the US. Instead, US practitioners tend to favor granule powders or extracts that can be taken off the shelf and given directly to patients in a sealed bottle with full GMP compliance.
Despite these limiting factors of home extractors in comparison with large commercial approaches, they are clearly an excellent delivery system. The home extractors currently dominating the Chinese and Korean TCM landscape are one of the most prominent herbal medicine developments in our time, offering practitioners their own mini-factory, an intermediary choice between stovetop technology and full-scale industrial technology. Their popularity in Asia has reached a critical mass, many studies have been published that show favorable results when comparing pressure-cookers with home decoction methods. Seeing the quantifiable improvement in extraction efficiency achieved by cooking medicinals under pressure gives one an appreciation for the sophistication and science of the herbal medicine industry. As pressure cooking is only one aspect of advanced extract production, I suspect that in coming years we will see many more scientific reports that deepen our appreciation for the amazing developments in this modern age of herbal medicine.
Part Three: Trends in the Americas
Practitioners in the Americas use a diverse blend of methods and dosage forms. Korean extractors exist on the market and are prominent in Korean clinics, but they are rarely seen outside of the Korean community. Many Western practitioners use granules, and raw herbs are generally available. While most patients in Asia as well as the West abhor the taste of Chinese herbal medicine, one of the most striking aspects of the Western market is the variety of approaches used to reduce or mask the taste of Chinese herbal medicine. Gelcaps, tablets, syrups, liquors, and pastes are seen throughout the global world of Chinese medicine, but it is only in the West that these forms constitute a large portion of the practitioner-prescribed herbal medicine.
One of the most distinctive features of Chinese herbal medicine in the Americas is the widespread use of alcohol/water liquid concentrates and tinctures. Tinctures are traditional preparations that use a combination of soaking and maceration in alcohol, while the liquid concentrates are generally made by slow-cooking the herbs in an alcohol/water medium and reducing the liquid under low heat. These liquid concentrates and tinctures are not really seen on the marketplace in Asia, so in a sense they can be considered to be a distinctive feature of the practice of Chinese medicine by Western practitioners.
In Western herbal medicine, many substances are made into alcohol tinctures, which are the taken by the dropper. However, the Western-style tincture typically utilizes lower doses of plant product than the prescriptions of clinical Chinese medicine, and most historical Chinese formulas used only water rather than alcohol to extract the medicinals. Chinese medicine definitely has a rich tradition of making herbal liquors, but alcohol is only used for certain situations. Alcohol is considered to have a warming and freeing action that helps to quicken the blood. Because of this, medicinal liquors are commonly used in the treatment of impediment disease as well as in supplementing wines.
Alcohol is regarded as a distinct medicinal substance in Chinese medicine, and it is found in classical formulas such as gua lou xie bai bai jiu tang (Trichosanthes, Chinese Chive, and White Alcohol Decoction) from the Jin Gui Yao Lue (“Essentials from the Golden Coffer”). Most traditional practitioners believe that the warm, acrid nature of alcohol must be taken into account when using it in formulas, so it is often considered to be a less-than-ideal medium for heat-clearing formulas, such as yin qiao san (Lonicera and Forsythia Powder). Furthermore, while traditional Chinese herbal liquors are highly effective for gradual, long-term supplementation or slow, enduring treatment of impediment disease, liquors and tinctures are generally inadequate for delivering the doses required when decoction formulas are indicated.
Many Western patients are new to Chinese medicine, and strong-tasting herbs with unfamiliar delivery forms are not always easily accepted by Western patients. Consequently, many practitioners attempt to adapt the familiar Western tincture-bottle delivery form when using Chinese medicine. The harsh taste and comparatively low concentration of a traditional tincture has led some innovating companies to create water/alcohol extracts, which are concentrated at low heat to form a liquid concentrate. Glycerin may be added during this process to sweeten the flavor and strengthen the natural preservative effect of the alcohol. While this delivery method is often very acceptable to Western patients, it is difficult to concentrate a liquid extract beyond 1 gram of crude herb per milliliter of extract. Consequently, practitioners must either prescribe liquids at a dose that is significantly lower than the dosage used in a standard decoction, or else they must recommend quantities of liquid extracts that greatly exceed the standard few droppers used in Western herbal medicine.
Additionally, the use of alcohol as a solvent introduces unknown variables because most Chinese herbal formulas were historically only used as a water-based decoction. Alcohol is a very effective solvent, and undoubtedly some Chinese herbs are highly suited to alcohol extraction. Yet while increased beneficial effects may be achieved with some herbs by using alcohol as a solvent, other herbs may have alcohol-soluble constituents that have undesirable or even harmful effects that are not present when the herb is used in a traditional decoction. Because of this unknown confounding variable, many practitioners and researchers choose to emphasize only water-based extracts for formulas that were traditionally administered by decoction.
In an effort to find products that can achieve standard Chinese medical dosage levels while avoiding the strong herbal taste, many practitioners in the Americas choose to use concentrated extracts in a gelcap form. While this method is generally regarded as the best solution to the problems of dosage, convenience, and flavor, it has the disadvantage of being labor-intensive for a practitioner who gives customized formulas to each patient. For practitioners that can effectively use classical formulas on their own or in combination with other formulas on the market, capsules are often the best solution for patients that cannot accept the taste of raw herbs or granules. Capsules made from concentrated extracts can be purchased for a fraction of the cost of liquid extracts and compare favorably to granules and raw herbs in terms of value.
A key consideration with encapsulated products is the concentration ratio of the extract used. Because each gelcap holds only about 500mg, encapsulated products should be made with highly concentrated extracts that lack fillers. Generally speaking, capsules or tablets are only able to approximate the daily doses used in Chinese medicine if patients either consume large numbers of capsules or if practitioners prescribe concentrates that are at least 7:1 to 10:1. A single 10:1 gelcap provides the equivalent of about five grams of raw herbs, so patients can achieve decoction-strength doses with only 9—12 capsules per day. A high concentration is preferred because raw herbal formulas typically require 50 grams of crude drug per day or more, and patient compliance is much higher with 10 capsules of a 10:1 extract than with 20 capsules of a 5:1 or even 40 capsules of a 2.5:1 extract.
It could be said that the greatest overall differences in Chinese herbal medicine between the US and Asia relate to dosage. In Asia, raw herbs are generally taken by decoction at a dose of one pack per day, whereas in the Americas, one pack of raw herbs is often taken for two days. Despite the fact that North American patients tend to have a higher body weight than their Asian counterparts, they often consume Chinese herbs at a dosage that is essentially half of the traditional dose.
In a similar paradox, Taiwanese granules are often prescribed at doses that are a fraction of the doses used in Taiwan. Part of the confusion seems to lie with the labeling information, which is required by US law to state a specific dose. Given the litigious nature of American society, most companies are understandably cautious in their dosage recommendation, so the dosage listed on the label is often well-below the dosage that is regularly used by a trained practitioner. Furthermore, most loose granules have the Asian labeling on concentration ratios removed for the US market, so practitioners are often at a loss to know how the powder corresponds to the raw herbal weight.
Taiwanese granules are generally used at a dose of around 18g/day in Taiwan, but many practitioners in the US use doses as low as 4—6 g/day. Perhaps the majority of Western practitioners prescribe granules in a dose range of around 6—12g/day, but many practitioners remain uncertain about how proper granule dosing is determined. Additionally, many instructors in American schools come from China but teach in schools that stock Taiwanese granules, which are more prominent on the American market. The granule product is different than what they used in their training in China, and teachers cannot effectively educate students on granule dosage because the standard raw dose equivalent is absent from the label. Consequently, practitioners often rely on the label information, which is essentially just an overly cautious (read: “please don’t sue me”) guideline that is required by FDA laws.
Truly we live in a diverse time. Everywhere around the world, cultures are interacting at a pace that has never been seen before. This cultural exchange allows us to really learn about what’s going on in the global world of Chinese medicine, and it is surprising to see how many differences there are between the West and the East. Certainly within East Asia alone there is an incredible diversity of medical approaches, and as Chinese medicine continues to globalize, the scope of these fascinating cultural encounters will only continue to increase. I wonder how they’ll start dosing granules in Africa, I really do.
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