1. Purpose of Preparation
1. Master the general process of preparing small pill forms.
2. Understand the usage of the small pill preparation machine and the quality inspection methods for small pills.
2. Principle of Preparation
Dripping pills refer to the preparation made by heating and melting solid or liquid medicines with a matrix, then dripping them into a non-miscible cooling liquid, which shrinks and condenses to form the dosage form. The process of making these dripping pills is essentially about forming solid dispersions into pill forms. They can be taken orally or applied externally. The main characteristics include rapid efficacy, high bioavailability, and minimal side effects. They can also be made into various types of sustained-release and controlled-release dripping pills. Dripping pills can convert liquid medicines into solid forms, enhance the stability of the drugs, and the production equipment is simple and easy to operate.
3. Experimental Content and Operation
Preparation of **Yunxiang Oil** Dripping Pills
1. Formula
**Yunxiang Oil** (Citrus aurantium) 835g (equivalent to 948.9ml)
**Sodium Stearate** 100g
**Beeswax** 25g
**Water** 40g
2. Preparation: Add the first three ingredients into a flask and shake well, then add water and shake again. Insert a rubber stopper with a reflux condenser into the flask, and while shaking continuously, heat to about 100°C until completely melted. Cool to 77°C, then transfer to the storage bottle of the Yunxiang oil pill machine. The inner diameter of the glass tube is 4.9mm, outer diameter 8.04mm, and the temperature of the incubator is about 65°C, with a dripping speed of 120 pills/min. Drip into a 1% sulfuric acid solution, retrieve the pills, briefly immerse them in cold water, and place them on a tray lined with absorbent paper to remove moisture before packaging.
3. Operational Notes:
This product utilizes the principle of wax pills, where **Yunxiang Oil** is combined with **Sodium Stearate** and **Beeswax** to form a molten oil liquid when heated, which is then dripped into a 1% (ml/g) sulfuric acid cooling liquid. Due to interfacial tension, it shrinks and condenses into pills. Using 1% sulfuric acid as the cooling liquid allows the sodium stearate to react with the acid to form stearic acid, resulting in a layer of stearic acid and beeswax on the surface of the pills, which does not dissolve in gastric fluid but dissolves in the alkaline environment of the intestine, forming enteric-coated pills and overcoming side effects such as nausea and vomiting associated with **Yunxiang Oil** tablets.
The method for preparing sodium stearate is: dissolve 1 part of anhydrous sodium carbonate in distilled water, heat, and slowly add finely ground stearic acid while stirring continuously. Once boiling stops and the reaction is complete, evaporate, dry, and grind to a 60-mesh powder.
Due to sodium stearate’s ability to form a gel with **Yunxiang Oil**, the oil content reaches 94.9% (V/W).
Using acidic water as the cooling liquid ensures that the surface layer of sodium stearate on the pills becomes insoluble stearic acid, preventing the pills from dissolving in the cooling water.
Preparation of **Glycerin Gelatin** Blank Dripping Pills
1. Formula
**Glycerin** 14g
**Gelatin** 4g
**Water** 2g
2. Preparation: Mix glycerin, gelatin, and water, heat to dissolve, and transfer to a storage device for dripping at 80°C, controlling the dripping speed to 30 pills/min. Drip into a cooling liquid of dimethyl siloxane cooled with ice water. After dripping is complete, let sit for 0.5 hours, retrieve the pills, place them on a tray lined with absorbent paper to remove moisture, and dry to control moisture content before quality inspection and packaging.
Operational Notes:
For dripping, either dimethyl siloxane or liquid paraffin can be used as the cooling liquid. The density of dimethyl siloxane is 0.930-0.975, while liquid paraffin has a relative density of 0.86-0.89. Dripping pills in dimethyl siloxane allows for slower sedimentation, facilitating pill formation.
The dripping machine used is a downward dripping machine.
Quality Inspection and Evaluation:
Evaluate the appearance of the pills.
Take 20 pills and measure according to the methods outlined in the Chinese Pharmacopoeia, ensuring compliance with requirements.
Dissolution rate measurement: according to the methods outlined in the Chinese Pharmacopoeia, ensuring compliance with requirements.
Sterility check: according to the methods outlined in the Chinese Pharmacopoeia, ensuring compliance with requirements.