Hello everyone, I am Xiao Zhou. Today we will discuss a special category of TCM formulations, pills. Pills are solid preparations shaped like spheres or quasi-spheres made from raw medicinal materials and suitable excipients. Pills are a traditional dosage form in TCM and are widely used. This section focuses on honey pills, drop pills, and the quality requirements for pills.
Key Points:
I. Overview
1. Definition and Characteristics of Pills Advantages of pills: ① Different types of pills release drugs and act at different speeds. ② Solid, semi-solid, and viscous liquid medicines can all be made into pills. ③ Pills improve the stability of medicines and reduce irritability. Aromatic medicines or those with special unpleasant odors can be placed in the inner layer of the pill or coated to mask the smell. Making paste pills or wax pills can also reduce toxicity and adverse reactions. ④ The preparation method is simple, suitable for both small-scale and industrial production. Disadvantages of pills: ① Some traditional varieties have large doses, making them inconvenient to take, especially for children; ② Improper control during preparation can lead to slow disintegration; using raw powder can lead to microbial contamination.
2. Classification of Pills1. Classification by Excipients According to different excipients, pills can be classified into water pills, honey pills, water-honey pills, concentrated pills, paste pills, wax pills, and sugar pills. 2. Classification by Preparation Method According to different preparation methods, pills can be classified into pan-made pills, plastic pills, and drop pills. (1) Pan-made pills: Refers to spherical preparations made by moistening or binding fine powdered medicines with suitable liquids, such as water pills and some water-honey pills, concentrated pills, paste pills, etc. (2) Plastic pills: Refers to pills made from a mixture of fine powdered medicines and suitable binders, shaped by a pill machine or mold, such as honey pills and some paste pills, concentrated pills, etc. (3) Drop pills: Refers to spherical or quasi-spherical preparations made by heating and melting raw medicines with suitable matrices and dropping them into a non-miscible, non-reactive condensing medium.
II. Water Pills1. Definition and Characteristics of Water Pills Water pills, commonly known as water pan pills, refer to pills made from fine powdered medicinal slices using water (or other suitable liquids such as yellow wine, vinegar, diluted medicinal juice, sugar solution, or water solution containing less than 5% honey) as a binder. The size specifications of water pills are traditionally described using physical references, such as the size of mustard seeds or phoenix tree seeds. Currently, the weight of a certain number of pills or the weight of each pill is specified, such as Meihua Dian She Wan, where every 10 pills weigh 1g, and She Xiang Bao Xin Dan, where each pill weighs 22.5mg. 2. Excipients for Water Pills1. Water 2. Alcohol Alcohol helps to extract alkaloids, volatile oils, and other components, has certain preservative capabilities, and aids in the drying of the final product. Yellow wine or white wine is commonly used. 3. Vinegar Vinegar helps to increase the extraction of alkaloids from the medicinal powder, facilitates absorption, and enhances efficacy. Rice vinegar (containing 3% to 5% acetic acid) is commonly used as an excipient. 4. Medicinal Juice ① Fibrous plant medicines (such as Da Fu Pi, Si Gua Luo, etc.) and hard mineral medicines (such as magnetite, natural copper, etc.) can be made into decoctions for use in pan pills; ② Extracts, gels, and resinous medicines such as frankincense, myrrh, or soluble salts (such as Glauber’s salt) can be dissolved and used as binders; ③ Bamboo juice, milk, bile, etc., can be diluted with water for use; ④ Fresh medicines (such as ginger, garlic, etc.) can be juiced for use in pan pills.
III. Honey Pills (Including Water-Honey Pills)1. Definition, Types, and Characteristics of Honey Pills Honey pills refer to pills made from fine powdered medicinal slices using processed honey as a binder. Each pill weighing 0.5g (including 0.5g) or more is called a large honey pill, while those weighing less than 0.5g are called small honey pills. Water-honey pills refer to pills made from fine powdered medicinal slices using both processed honey and water as binders. 2. Selection and Processing of Honey1. Requirements and Selection of Honey 2. Processing of Honey The honey used for honey pills must be processed to: remove impurities, destroy enzymes, kill microorganisms, reduce moisture content, and increase viscosity, etc. (1) Methods of processing honey (2) Specifications for processed honey: Depending on the degree of processing, processed honey can be classified into tender honey, medium honey (processed honey), and old honey, suitable for different types of medicinal powders. Tender Honey: Processed at temperatures of 105℃ to 115℃, with a moisture content of 17% to 20%, a relative density of about 1.35, with no significant color change and slight stickiness. Suitable for making pills from medicinal powders with high mucilage, gelatin, sugar, starch, fats, and animal tissues. Medium Honey (Also Known as Processed Honey): Processed at temperatures of 116℃ to 118℃, with a moisture content of 14% to 16%, a relative density of about 1.37, with surface bubbles appearing during processing. It is sticky when pinched between fingers, but no long white threads appear when fingers are separated. Suitable for making pills from medicinal powders with medium stickiness, commonly used for most honey pills. Old Honey: Processed at temperatures of 119℃ to 122℃, with a moisture content of less than 10%, a relative density of about 1.40, appearing reddish-brown. During processing, large bubbles appear, and it can form beads when dropped into cold water. It is very sticky when pinched, and long white threads appear when fingers are separated. Suitable for making pills from medicinal powders with low stickiness or those rich in fiber.
IV. Concentrated Pills Concentrated pills refer to pills made from extracts of medicinal slices or parts of slices that are concentrated and mixed with suitable excipients or remaining fine powdered slices, using water, processed honey, or a mixture of processed honey and water as binders. Depending on the binder used, they can be classified into concentrated water pills, concentrated honey pills, and concentrated water-honey pills. V. Paste Pills Paste pills refer to pills made from fine powdered medicinal slices using rice paste or flour paste as a binder. “Taking its slow effect” can prolong the efficacy; toxic or irritating medicinal slices, as well as those requiring delayed effects, can be made into paste pills.VI. Wax Pills Wax pills refer to pills made from fine powdered medicinal slices using beeswax as a binder. Wax pills do not disintegrate in the body, releasing the medicine slowly and persistently, similar to modern sustained-release and controlled-release formulations. Toxic or highly irritating medicines can have their toxicity and irritation reduced by making them into wax pills. Chuan Bai Wax and paraffin cannot be used to make wax pills.
VII. Drop Pills1. Definition and Characteristics of Drop Pills Drop pills refer to spherical or quasi-spherical preparations made by heating and melting raw medicines with suitable matrices and dropping them into a non-miscible, non-reactive condensing medium. The main characteristics of drop pills are: ① High bioavailability, especially for poorly soluble medicines, which can form solid dispersions in water-soluble matrices, dissolve quickly, and act rapidly, making them suitable for emergency treatment; ② Drop pills have accurate dosages, with the medicine evenly dispersed in the matrix, resulting in minimal weight differences; ③ Different matrices can be selected to create formulations with different drug release rates (such as sustained-release and controlled-release formulations), allowing liquid medicines to be solidified (e.g., polyethylene glycol matrices can accommodate 5% to 10% liquid); ④ The production equipment is simple, the production cycle is short, the degree of automation is high, and production costs are low. ⑤ The drug load of drop pills is relatively small, and currently, there are limited ideal matrices and condensing agents available, which restricts their development.
2. Common Matrices for Drop Pills Drop pill matrices can be classified into water-soluble and non-water-soluble types: ① Water-soluble matrices, commonly used include polyethylene glycol (such as PEG 6000, PEG 4000, etc.), Poloxamer, stearic acid polyoxyethylene (40) ester (brand name S-40), gelatin, glycerin gelatin, sodium stearate, etc.; ② Non-water-soluble matrices, commonly used include stearic acid, monostearin, hydrogenated vegetable oil, carnauba wax, beeswax, and cetyl alcohol. Different types of matrices can also be used in combination, such as mixing PEG 6000 with stearic acid in a certain ratio to increase the solubility of the drug, adjust the drug release or disintegration time, and facilitate the preparation of the pills.
VIII. Sugar Pills
Sugar pills refer to preparations made by using appropriately sized sugar granules or core pills, with a mixture of sugar powder and other excipients as the coating material, selecting suitable binders or wetting agents to form pills, and wrapping the raw medicinal materials in sugar pills in suitable methods. They are sweet, easily dissolve, and are suitable for pediatric use, often used in vaccine formulations.
IX. Coating of Pills1. Purpose of Coating2. Types and Materials of Coating1. Medicinal Coating Coating materials are extremely fine powders made from prescription medicines, which have certain pharmacological effects. They are used for coating to exert therapeutic effects while protecting the pills and enhancing their appearance. Common medicinal coatings include vermilion coating (commonly used for sedative, calming, and heart-nourishing medicines), Huangbai coating (commonly used for dampness-draining, water-permeating, and clearing damp-heat in the lower jiao), Xionghuang coating (commonly used for detoxifying and insecticidal medicines), Qingdai coating (commonly used for clearing heat and detoxifying medicines), and Baicao Frost coating (commonly used for clearing heat and detoxifying medicines).2. Protective Coating Using stable materials with no significant pharmacological effects to coat the pills, isolating the main medicine from the external environment for protection. Common materials include film coatings, sugar coatings, colored sugar coatings, gelatin coatings, etc. 3. Enteric Coating Using enteric materials (such as acrylic resin types I, II, III, cellulose acetate phthalate, etc.) to coat the pills, allowing them to remain undissolved in gastric fluid but dissolve in intestinal fluid.
X. Quality Requirements for Pills Unless otherwise specified, the moisture content in 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%. Wax pills and drop pills are not checked for moisture content. Disintegration time limits: small honey pills, water-honey pills, and water pills should completely disintegrate within 1 hour; concentrated pills and paste pills should completely disintegrate within 2 hours; drop pills should completely disintegrate within 30 minutes, and coated drop pills should completely disintegrate within 1 hour. Wax pills are checked according to the disintegration time limit for enteric-coated tablets, tested in hydrochloric acid solution (9→1000) for 2 hours, with no cracks, disintegration, or softening, and then tested in phosphate buffer (pH 6.8) for 1 hour, where they should completely disintegrate. Unless otherwise specified, large honey pills and pills that are crushed, chewed, or dispersed in boiling water, yellow wine, etc., are not checked for disintegration time limits.
Exercises:
1. Which of the following statements is correct?
A. Medicines with high sugar and oil content require more honey as a binder.
B. Mineral substances have low stickiness and require tender honey and medicine.
C. Resinous medicines should use hot honey above 80℃.
D. Medicines with high fiber or mineral content should use old honey and medicine.
E. Aromatic volatile medicines such as musk and borneol should use hot honey and medicine.
2. The medicinal powders used for coating traditional TCM pills are made from extremely fine powders of the prescription medicines. According to the prescription, which coating is commonly used for dampness-draining, water-permeating, and clearing damp-heat in the lower jiao?
A. Vermilion coating
B. Huangbai coating
C. Xionghuang coating
D. Qingdai coating
E. Zheshi coating
3. (Multiple choice) Unless otherwise specified, which pills do not require moisture content checks?
A. Paste pills
B. Drop pills
C. Honey pills
D. Wax pills
E. Concentrated pills
4. Unless otherwise specified, which pills do not require disintegration time checks?
A. Paste pills
B. Drop pills
C. Small honey pills
D. Large honey pills
E. Coated drop pills
Answers and Explanations:
1.D
This question tests the specifications, processing requirements, and applicable ranges of honey. Medicines with high fiber or mineral content should use old honey and medicine (D is correct, B is incorrect). Old honey is suitable for making pills from medicinal powders with low stickiness or those rich in fiber. Medicines with high sugar and oil content require less honey (A is incorrect). Resinous medicines should use hot honey above 80℃ (C is incorrect). Aromatic volatile medicines (musk, borneol, etc.) should use hot honey and medicine (E is incorrect).
2.B
This question tests the function of medicinal coatings. Huangbai coating is commonly used for dampness-draining, water-permeating, and clearing damp-heat in the lower jiao (B is correct). Vermilion coating is commonly used for sedative, calming, and heart-nourishing medicines (A is incorrect). Xionghuang coating is commonly used for detoxifying and insecticidal medicines (C is incorrect). Qingdai coating is commonly used for clearing heat and detoxifying medicines (D is incorrect). Zheshi coating (E is incorrect) is not explicitly required in the outline.
3.BD
This question tests the moisture requirements for pills. The moisture requirements for pills are: honey pills and concentrated honey pills < 15.0% (CE is incorrect); water-honey pills and concentrated water-honey pills < 12.0%; water pills, paste pills (A is incorrect), and concentrated water pills < 9.0%. Wax pills (D is correct) and drop pills (B is correct) do not require moisture checks.
4. D
This question tests the disintegration time limits for pills. Unless otherwise specified, the pills that do not require disintegration time checks are large honey pills (D is correct) and those that are crushed, chewed, or dispersed in boiling water, yellow wine, etc. Concentrated pills and paste pills (A is correct) should completely disintegrate within 2 hours. Drop pills (B is incorrect) should completely disintegrate within 30 minutes. Small honey pills, water-honey pills, and water pills should completely disintegrate within 1 hour (CE is incorrect).
Xiao Zhou, the Pharmacist, says:
There are many types of pills, including water pills, honey pills, water-honey pills, concentrated pills, paste pills, wax pills, sugar pills, drop pills, etc. However, the focus is on a few points: first, the selection of tender honey, processed honey, and old honey for honey pills. Tender honey is thin, while old honey is thick and sticky, so tender honey is better for highly viscous medicinal materials, while old honey is suitable for those with low stickiness and high fiber content. Medium honey is generally used for honey pills. Next, the characteristics of drop pills are known; for example, Suoyao Jiuxin Wan is a drop pill, and the greatest feature of drop pills is their use in emergencies. In contrast, wax pills and paste pills release drugs slowly. Additionally, the coatings for pills include Xionghuang for detoxification and insecticidal purposes, Baicao Frost and Qingdai for clearing heat and detoxifying, and vermilion for calming and soothing the heart. Finally, the quality requirements for pills include two important checks: moisture content and disintegration time. The moisture content for medium honey pills and concentrated honey pills is up to 15%, water-honey pills and concentrated water-honey pills 12%, and water pills and paste pills 9%. Drop pills and wax pills are not checked. The disintegration time for drop pills is the fastest, within half an hour. After coating, drop pills take an additional half hour, completing disintegration within one hour. Small honey pills, water-honey pills, and water pills should completely disintegrate within one hour; concentrated pills and paste pills have the longest time, completing disintegration within two hours.