Pills (10 grams is approximately one small bottle cap): The pills made in medical institutions are water honey pills, approximately 0.1 grams per pill. The preparation of pills involves grinding the prescribed medicinal materials into powder or concentrating them into a paste before forming them into pills.Ask a TCM Expert.
Preparation of Traditional Chinese Medicine Pills
Pills are spherical solid preparations made from powdered medicinal substances or extracts combined with binders or excipients. Pills are absorbed slowly, have a lasting effect, and are convenient for taking, making, carrying, and storing.
Records of pills made with binders such as wine, grease, and vinegar for internal use can be found in the “Fifty-Two Disease Formulas” from the Warring States period. The “Inner Canon” and “Treatise on Cold Damage” as well as later medical literature provide more abundant information on the preparation and application of pills.
With the development of TCM and advancements in preparation techniques, various types of pills made with different binders and excipients are increasingly available. Pills are absorbed slowly, have a lasting effect, and are convenient for taking, making, carrying, and storing. However, the disadvantages include a long production process, many opportunities for contamination; improper operation can affect disintegration and efficacy; it is difficult to standardize effective components; and some require larger doses, making it difficult for children to take.
Pills are generally suitable for chronic diseases or patients with long-term deficiencies, such as Shi Quan Da Bu Wan (Ten Complete Great Tonifying Pill). Certain potent medications used to treat blood stasis and menstrual disorders, which are not suitable for decoction, must also be made into pills to allow for gradual efficacy, such as Bie Jia Jian Wan (Soft-Shelled Turtle Shell Pills) and Da Huang Chong Wan (Rhubarb and Insect Pills). There are also medications for emergency use, but those containing aromatic components should not be heated and should be made into pills, such as An Gong Niu Huang Wan (Calm the Palace Pill with Cattle Gallstone) and Su He Xiang Wan (Scented Pill). Additionally, some precious or difficult-to-decoct herbs, or those whose efficacy is destroyed by high-temperature decoction, should be made into pills.
Pill Classification
Honey Pills are made with honey as a binder and are the most widely used. They are suitable for chronic and deficiency diseases. Depending on the size of the pills and the method of preparation, honey pills can be classified into large honey pills, small honey pills, and water honey pills. Large and small honey pills are made with refined honey as a binder and are formed into plastic solid preparations, with larger pill sizes, such as Yin Qiao Jie Du Wan (Yin Qiao Detoxifying Pills) and Liu Wei Di Huang Wan (Six Flavor Rehmannia Pills). Water honey pills use honey water as a binder and are made into dried preparations, with smaller pill sizes, especially suitable for production and application in humid climates, such as Da Bu Yin Wan (Great Yin Tonifying Pills).
Water Pills are made using cold boiled water, medicinal juice, or prescribed wine or vinegar as binders, also known as water-fan pills. During preparation, layers can be added according to the properties and odors of the herbs to mask unpleasant smells and prevent the loss of aromatic components. Water pills dissolve and disperse more easily than honey pills and paste pills, thus having a quicker absorption and effect, such as Fang Feng Tong Sheng Wan (Siler and Detoxifying Pills).
Paste Pills are made using rice paste or flour paste as excipients. Paste pills dissolve slowly after ingestion, prolonging the efficacy and reducing gastrointestinal irritation, suitable for preparing pills containing highly toxic or irritating herbs (such as Ba Dou, Wu Tong, Sheng Ban Xia, Mu Bie Zi, Dan Yao, etc.). Additionally, pills that are to be dissolved in saliva or ground into juice should also be made into paste pills. Due to their high viscosity, the disintegration of paste pills is difficult to control, and if not properly prepared and stored, they are prone to mold, thus they are less commonly used.
Wax Pills are made using beeswax as a binder. Wax pills release the medication very slowly in the body, prolonging the effect and preventing toxicity and gastrointestinal irritation. Any prescription containing a significant amount of highly toxic or strongly irritating herbs that need to dissolve and release in the intestines should be made into wax pills. The preparation of wax pills is relatively difficult and thus not widely used.
Concentrated Pills are made by concentrating part or all of the medicinal extract into a clear paste or extract, then mixing it with the remaining powdered herbs or excipients, and drying it. They are also known as powder paste preparations. Concentrated pills are developed based on honey pills and water pills, maintaining the characteristics of pills while reducing the volume of the medication, making them easier to dissolve and absorb, thus enhancing efficacy, such as An Shen Bu Xin Dan (Calming and Heart Tonifying Pill). The preparation, storage, transportation, and administration of concentrated pills are convenient, making them a promising dosage form among pills.
Drip Pills are a new type of pill made using solid dispersion technology. They use a low melting point lipid-soluble matrix or water-soluble matrix to dissolve, emulsify, or suspend solid or liquid medications in the molten matrix, which is then dripped into a cooling liquid that does not mix with it, causing the molten droplets to solidify into pills. Drip pills are easy to prepare, require a small dosage, and are suitable for medications containing volatile oils, such as Su Bing Di Wan (Sublingual Drip Pills), Yun Xiang You Di Wan (Yun Xiang Oil Drip Pills), and Mu Jing Di Wan (Vitex Drip Pills).
Preparation of Pills
>> Preparation of Honey Pills
The method for honey pills includes steps such as refining honey, combining with herbs, forming strips, making pills, packaging, and storage.
The selection and refining of honey are key to ensuring the quality of honey pills. Generally, honey that is milky white and light yellow, sweet and fragrant, free of impurities, thick like congealed fat, and low in moisture is preferred. However, due to variations in source, region, and climate, the quality can vary. Honey produced in the north generally has less moisture, with Jing Tiao Honey and Jujube Flower Honey being the best, while honey produced in the south generally contains more moisture.
The purpose of refining honey is to remove impurities, destroy enzymes, kill microorganisms, evaporate moisture, and enhance viscosity.
The method is: for small-scale production, a copper pot or direct fire heating can be used for refining; for large-scale production, a steam jacketed pot or vacuum evaporator can be used for refining, and finally, impurities are filtered out.
The degree of honey refining is classified into tender honey, refined honey, and old honey.
Tender honey – heat the tender honey to boiling, reaching a temperature of 110-114 degrees, the color darkens, it becomes viscous, and loses about 3% moisture. It is suitable for formulas containing a lot of fat, starch, mucilage, sugars, and animal tissues.
Refined honey – continue heating the tender honey to a temperature of 110-116 degrees, producing shallow red glossy bubbles, with strong stickiness but no white threads, losing about 13% moisture, suitable for formulas containing fibrous materials, starch, sugars, and some oils.
Old honey – continue heating the refined honey until it turns brownish-red with a red gloss, very sticky to the touch, and can pull out white threads, with a temperature of 118-122 degrees. It is suitable for formulas containing a large amount of cellulose and minerals.
>> Preparation of Water Pills
Method: Water pills are prepared using the fan method. There are two types of fan methods: manual and mechanical, with the same operating principles, mainly involving raw material processing, molding, forming, selecting cover surfaces, drying, coating, polishing, and quality inspection. Molding is a key step.
1. Raw material processing: Process each herb in the prescription according to requirements, then grind and sieve through a 100-mesh screen for later use.
2. Molding: The pill mold is the basis for forming using the fan method. There are two methods: manual molding and mechanical molding.
Method 1: Manual molding: In a clean, dry bamboo tray, moisten 1/4 of the surface with a brush dipped in a little water, sprinkle a small amount of powder on the wet surface, hold the tray with both hands, rotate it to moisten all the herbs, then gently brush down the moistened small particles to the other side (dry side), sprinkle a little fine powder, and shake the tray to ensure all small particles are evenly coated with the powder, then return to the wet area to roll them in water, and repeat this process until small round particles (approximately 0.5-1mm in diameter) are formed, and the mold is ready for selection and enlargement.
Method 2: Mechanical molding: Sprinkle the herb powder into a coating pot, and while the pot rotates, spray water to moisten the powder into small particles, then add a small amount of fine powder, and continue rolling for a certain time to solidify the small particles, then spray water and sprinkle powder, repeating this process until a regular pill mold is formed, which is then screened for further shaping.
3. Enlarging the mold: Once the mold is formed, continuously rotate the bamboo tray, alternating adding water and powder, and keep turning the tray, with the basic actions being kneading and flipping, to enhance the hardness and roundness of the pills until they gradually enlarge to meet the requirements (the same applies to manual and mechanical methods).
4. Selecting Pills: Use an appropriate sieve to select uniform pills, and re-fan any that are too small, while separating and appropriately handling any oversized or deformed pills.
5. Covering the Surface: The purpose of covering the surface is to make the pill surface dense, smooth, and uniform in color. Common methods include dry powder coating, water coating, and liquid coating.
6. Drying: Since water pills contain a lot of moisture, they should be dried promptly (below 60 degrees). During drying, the temperature should be gradually increased, and the pills should be turned frequently to avoid uneven drying.
>> Preparation of Paste Pills
Preparation of paste pills is similar to honey pills and is relatively simple. This preparation method is for reference. 1. Prepare the herbs according to the prescription, sun-dry until dry or dry at low temperature, grind and sieve through a 100-mesh screen (if you want to be lazy, you can sieve through an 80-mesh screen), remember to sieve two to three times, otherwise, the pills may have hair; 2. Weigh the sieved herb powder, remember the weight, and place it in a smooth bowl; 3. Measure an equal weight of cold water in a small pot; 4. Add one-tenth of the weight of flour or one-twentieth of the weight of glutinous rice flour to the water and mix well, breaking all bubbles; 5. Boil the mixed paste over heat, stirring to prevent sticking to the bottom, and once boiled, it becomes a paste; 6. Pour the paste into the herb powder and mix well to form a dough, kneading several times, then cover with a damp towel (or damp cloth, plastic wrap) and let it rest for a moment; 7. Pinch off a small amount of dough with your fingers and gently roll it into pills, placing them in a flat dish or large bowl and rolling them occasionally; 8. Dry or bake the rolled pills, disinfect with ultraviolet light, and store them for later use.
Note: 1) The weight ratio of herb powder to water and flour is 10:10:1, remember this ratio is just right; too much or too little water is not good for rolling pills; 2) If the herb powder contains non-water-soluble materials such as minerals or shells, the weight of these materials should be deducted from the herb powder weight, and water should be added according to the deducted weight; 3) If the formula contains herbs with high oil content, half of the weight of these herbs should be deducted from the herb powder weight when weighing and proportioning water, as oily herbs do not absorb much water; 4) During the kneading and rolling process, a lot of herb paste may stick to your hands, at this time, you can wet your hands in clean water and gently pat the large dough, allowing the herb paste to naturally adhere to the large dough, but do not operate frequently, otherwise, too much moisture will be added to the dough, which is not conducive to rolling pills; 5) If using a small pill-making machine, the ratio of herb powder to water and flour should be adjusted to 10:9:1, similarly deducting the weight of non-water-soluble herbs and proportioning water accordingly, as excess moisture often sticks to the machine, causing many troubles; 6) Hand-rolling pills is time-consuming and labor-intensive, and the size of the pills is difficult to control; patience is required to prepare the herbs.
>> Preparation of Wax Pills
Traditional wax pills in TCM include wax skin pills and wax pills, which are distinctly different in concept, preparation process, and use.
Wax Pills are made by mixing beeswax as a binder with powdered herbs. Since beeswax mainly contains soft fatty acids and has low polarity, it is insoluble in water, and pills made from it release medication slowly in the body, prolonging the effect. Adjusting the amount of beeswax can also allow the pills to be inactive in the stomach but effective in the intestines, thus preventing toxicity or strong irritation to the stomach. “Wax pills are difficult to dissolve and take effect slowly, or prevent toxins from harming the spleen and stomach,” making them the preferred dosage form for internal preparations containing a significant amount of highly toxic and irritating herbs. Traditional wax pills include San Huang Bao La Wan (Three Yellow Treasure Wax Pills), Shu Mi Cun Jin Dan (Millet Inch Gold Pill), and Zhi Lou Wu Shuang Wan (Double No. 1 for Hemorrhoids and Fistulas).
When preparing wax pills, the beeswax must be refined before use to remove impurities (refining can be done by bleaching or boiling). The refined wax is then heated until melted and allowed to cool slightly (around 60°C), when the edges begin to solidify and a film appears on the surface, the herb powder is added and quickly stirred to mix evenly, then rolled into pills while still warm.
Key operation: Control the temperature, mix with the herbs while warm, and quickly roll (to keep the temperature of the herb mixture around 60°C). If the temperature is too high, it becomes soft and difficult to shape; if too low, it becomes hard and difficult to roll. Some wax pills can also be sealed with wax skin and stamped with a name seal.
Wax Skin Pills are made from a mixture of beeswax and white wax (Chuan Bai Zhan) to form a wax shell (also called wax skin), which wraps the pills inside and seals them. Pills sealed with wax skin are mostly honey pills, with a small number being wax pills, and the prescriptions often contain aromatic, volatile, or precious materials. The purpose is to prevent the medication from contacting air, becoming contaminated, moldy, or undergoing physical and chemical reactions, preventing the loss of aromatic volatile components, and maintaining a certain moisture content in the pills to keep their hardness and softness consistent.
The preparation of wax shells, also known as “hanging wax skin,” is a complex process. The size of the wax shell is made according to the size of the pills, divided into five specifications, using a wooden ball of a certain specification as a mold, dipped in wax liquid, and allowed to solidify. The materials for making wax shells must be pure; impurities can cause the final product to crack or deform. The refining of beeswax, in addition to the methods mentioned above, also requires sun-waxing to decolorize. The mixing wax temperature is 55°C-59°C, with a ratio of 40% beeswax to 60% white wax, and the amount of white wax should be adjusted according to the season. Before dipping wax, the wooden ball should be boiled in water to increase its specific gravity, making it easier to dip in wax; the surface of the boiled wooden ball should be slightly damp, making it easier to peel off the wax shell.
The temperature of the wax liquid for dipping should be controlled at 70°C-74°C; if too high, the wax shell will be thin and easily deformed, and if too low, it will be thick and wasteful. The room temperature should be maintained at 18°C-25°C, so that the surface of the wax liquid does not form a film. After the wax shell is made, it is filled with pills and sealed; the temperature of the wax liquid for sealing should be 75°C-77°C. If too low, it will form two layers of wax skin or easily peel off and crack; if too high, the surface will be uneven. The sealed wax skin pills are stamped with a horn seal, heated over an alcohol lamp, and coated with gold, silver, or red powder to complete the product.
Traditional wax skin pills include Da Huo Luo Dan (Great Activating Pill), Wu Ji Bai Feng Wan (Black-Boned White Phoenix Pill), Su He Xiang Wan (Scented Pill), Ren Shen Zai Zao Wan (Ginseng Rejuvenation Pill), An Gong Niu Huang Wan (Calm the Palace Pill with Cattle Gallstone), Niu Huang Qing Xin Wan (Cattle Gallstone Heart-Soothing Pill), Tou Gu Zhen Feng Dan (Bone-Soothing Wind Pill), An Shen Zan Yu Wan (Calming and Nourishing Pill), Shen Rong Wei Sheng Wan (Ginseng and Deer Antler Health Pill), and San Huang Bao La Wan (Three Yellow Treasure Wax Pills).
Example (Source: Qing Dynasty, Wu Qian, “Medical Canon of the Golden Mirror”, Volume 75, Surgical Heart Method Essentials)
Prescription: Tian Zhu Huang 90 grams, Dang Gui 45 grams, Liu Ji Nu 90 grams, Hong Ya Da Ji (vinegar roasted) 90 grams, Teng Huang (tofu made) 120 grams, Er Cha 90 grams, Mang Xiao 30 grams. Ru Xiang (vinegar roasted) 9 grams, She Xiang 9 grams, Xue Jie 90 grams, Shui Yin (roasted) 9 grams, Hei Qian 9 grams, Hu Po 6 grams, Xiong Huang 90 grams, totaling 777 grams.
Preparation Method: 1. Grinding: “Grind the vermilion into a very fine powder, and separately grind the xiong huang, hu po, and she xiang into fine powder and sieve. Heat the hei qian in an iron pot until melted, then pour in the shui yin, stirring constantly with an iron spatula until it forms a sandy texture, then remove and let cool. The remaining Tian Zhu Huang and nine other ingredients are ground into fine powder and mixed well and sieved. 2. Mixing and coloring: Take 30 grams of fine vermilion powder and place it in a mortar, successively adding 90 grams of fine xiong huang powder, 6 grams of fine hu po powder, 9 grams of fine she xiang powder, and 672 grams of fine powder from the ten ingredients, using the coloring method to mix and sieve. 3. Making Pills: Take 720 grams of pure beeswax, heat until melted, and mix with the above herb powder until it reaches a congealed fat state, then place it in a copper plate. Maintain a certain temperature (to ensure it is sticky), take small pieces, and while warm, roll into strips to form pills.
Specifications: Smooth, round, uniform color, each pill weighs 3 grams.
Packaging: Sealed in wax skin or wax paper tubes, placed in a box for sealing.
Storage: Store in a cool, dry place indoors.
Function: Detoxification and blood stasis resolution.
Main Indications: Trauma and injury, blood stasis obstruction. External application for snake and insect bites.
Dosage and Administration: For internal use, take one pill, once or twice daily, decocted in yellow wine and taken warm; for children, reduce the dosage. For external use, add a little sesame oil, decoct and apply to the affected area. Or follow the doctor’s advice.
Contraindications: Pregnant women should avoid taking. Avoid eating raw and cold foods.
>> Preparation of Concentrated Pills
Concentrated pills can be prepared using the plastic molding method and the fan method, with the operating methods similar to honey pills (mechanically made small pills) and water pills. Generally speaking, when the formula has more paste and less powder, the fan method is preferred; when the paste and powder are balanced, mechanical methods can be used to make small pills; when there is more paste and less powder, the plastic molding method is preferred to ensure the quality and efficacy of the concentrated pills.
1. Plastic Molding Method: According to the properties of the medicinal materials in the prescription, take part of the herbs, decoct to extract the effective components and concentrate into a paste; mix evenly with the fine powder of other herbs, then add an appropriate amount of refined honey to form pill blocks of suitable hardness. Pills can be made according to the honey pill method, and concentrated paste can also be used as a binder; add fine powder of herbs or appropriate excipients to form pill blocks of suitable hardness, using mechanical extrusion to make pills, then dry the wet particles, screen, polish, and coat.
2. Fan Method: Take part of the herbs in the formula, decoct to extract the liquid or concentrated extract into a paste as a binder, and mix with the fine powder of other herbs to form pills. Alternatively, mix the thick paste with the fine powder to form blocks, dry, and grind into fine powder, using cold boiled water or different concentrations of ethanol as a wetting agent to form pills.
Quality Inspection
Moisture: Take the sample and measure moisture content according to the moisture determination method (Appendix IX H). Unless otherwise specified, the moisture content in large honey pills, small honey pills, and concentrated honey pills must not exceed 15.0%; water honey pills and concentrated water honey pills must not exceed 12.0%; water pills, paste pills, and concentrated water pills must not exceed 9.0%; micro pills are judged according to their respective pill types.
Weight Variation: For pills taken by weight, check according to the first method; for pills taken by number, check according to the second method.
First Method: For the maximum number of pills taken at one time, take 10 samples, weigh each, and compare with the labeled total weight (maximum number of pills taken × weight per pill) according to the table below. The number of samples exceeding the weight variation limit must not exceed 2, and no more than 1 sample may exceed the limit by double.
|
Labelled Total Weight |
Weight Variation Limit |
|
0.05g and below |
±12% |
|
Above 0.05g to 0.1g |
±11% |
|
Above 0.1g to 0.3g |
±10% |
|
Above 0.3g to 1.5g |
±9% |
|
Above 1.5g to 3g |
±8% |
|
Above 3g to 6g |
±7% |
|
Above 6g to 9g |
±6% |
|
Above 9g |
±5% |
Second Method: Take 10 pills as one sample, weigh each, and calculate the average weight; each sample’s weight should be compared with the average weight according to the table below. The number of samples exceeding the weight variation limit must not exceed 2, and no more than 1 sample may exceed the limit by double.
|
Average Weight of Each Sample |
Weight Variation Limit |
|
0.05g or below |
±12% |
|
Above 0.05g to 0.1g |
±11% |
|
Above 0.1g to 0.3g |
±10% |
|
Above 0.3g to 1g |
±8% |
|
Above 1g to 2g |
±7% |
|
Above 2g |
±6% |
Pills that require sugar coating should be checked for weight variation before coating, and only those that meet the above table’s requirements can be coated. After sugar coating, weight variation is no longer checked.
Volume Variation: The volume variation limit for pills packaged for one-time (or daily) dosage should meet the following table’s requirements.
|
Each Bag (Bottle) Labelled Volume |
Volume Variation Limit |
|
0.5g or below |
±12% |
|
Above 0.5g to 1g |
±11% |
|
Above 1g to 2g |
±10% |
|
Above 2g to 3g |
±8% |
|
Above 3g to 6g |
±6% |
|
Above 6g to 9g |
±5% |
|
Above 9g |
±4% |
Inspection Method: Take 10 bags (bottles) as samples, weigh the contents of each bag (bottle), and compare the volume of each bag (bottle) with the labeled volume according to the table below. The number of samples exceeding the volume variation limit must not exceed 2 bags (bottles), and no more than 1 bag (bottle) may exceed the volume variation limit by double.
Dissolution Time Limit: Unless otherwise specified, take 6 pills as samples, using a suitable mesh size sieve basket (for pills with a diameter below 2.5mm, use a sieve with a diameter of about 0.42mm; for those between 2.5mm and 3.5mm, use a sieve with a diameter of 1.0mm; for those above 3.5mm, use a sieve with a diameter of about 2.0mm), and check according to the dissolution time limit method under the tablet section. Unless otherwise specified, small honey pills, water honey pills, and water pills should dissolve completely within 1 hour; concentrated pills and paste pills should dissolve completely within 2 hours; the dissolution time limit for micro pills is judged according to their respective pill types. If during the operation, pills adhere to the sieve basket and hinder inspection, take another 6 pills as samples without the sieve basket and check according to the regulations; they should dissolve completely within the specified time.
All inspections should pass through the sieve within the specified time; if there are small particles that do not pass through but have softened and have no hard core, they can be considered qualified. Large honey pills are not checked for dissolution time limits.
Storage Methods
Honey pills and drip pills must be stored tightly and placed in a cool, dry place. The storage time for honey pills should not exceed 1 year.
Paste pills are most prone to insect infestation and should be stored in a dry place, tightly sealed, and checked every month or every two months.
Water Pills have a storage method similar to paste pills. Especially for pills containing aromatic herbs, they must be tightly sealed and protected from heat, with a storage time not exceeding 1 year.
Wax pills have excellent packaging and are not prone to spoilage or mold; they can be stored in a cool place.
Concentrated pills are often packaged in bottles or plastic bags, and storage and maintenance can refer to the methods for water pills and honey pills, but due to their strong moisture absorption, they are more prone to mold and insect infestation, so attention should be paid to sealing and moisture-proofing.
Administration Methods
Generally, administration should be chosen under the guidance of a physician. The dosage of pills is generally small, and blind high-dose administration should be avoided, as it can easily obstruct the stomach and spleen, leading to adverse consequences.
Swallowing Method: Most patients take TCM pills with warm boiled water. Large honey pills cannot be swallowed whole due to their size, so they are often chewed or broken into smaller pieces with clean hands before being taken with warm boiled water. Although the swallowing method is convenient, the medication is not easily digested and absorbed, especially for patients with stomach issues, who often feel uncomfortable after taking the medication.
Medication Drink Method: Sometimes, to enhance the therapeutic effect of TCM pills, doctors may advise patients to take them with medicinal drinks. For example, when taking Huo Xiang Zheng Qi Wan or Fu Zi Li Zhong Wan for stomach pain or vomiting, ginger decoction can be used.
Pill Boiling Method: First, crush the pills with an appropriate amount of warm boiled water to form a paste, then take the soup with residue. This method helps to extract and absorb the effective components of the medication, especially suitable for patients with poor gastrointestinal digestion and absorption.
This issue’s pill topic: In TCM, there are eight dosage forms: pills, powders, pastes, dan, wines, elixirs, soups, and tablets. Pills are absorbed slowly, have a lasting effect, and are convenient for taking, making, carrying, and storing, generally suitable for chronic diseases or patients with long-term deficiencies. Gradually accumulate professional knowledge in TCM, improving a little every day.
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