The principle of medicinal glass bottles mainly includes its airtightness principle and the principle of glass material adsorption on drugs.
Principle of airtightness
The sealing of medicinal glass bottles has an important impact on the quality of drugs. Glass bottles with poor sealing will cause the active ingredients in the drugs to volatilize and become ineffective, or be contaminated by external air or moisture, which will affect the stability and shelf life of the drugs. Therefore, medicinal glass bottles need to maintain good airtightness to ensure the quality and effectiveness of the drugs. The sealing of medicinal glass bottles is achieved by friction sealing between the lid and the mouth of the glass bottle. The rubber pad of the lid generates a certain friction force by pressing the mouth of the bottle, thereby achieving sealing. In addition, during the production process, its sealing can also be ensured by drying and sterilization. Drying can fully dehydrate the bottle mouth and increase friction, while sterilization can kill possible bacteria and prevent bacteria from growing in the bottle.
Principle of glass material adsorption on drugs
The material of medicinal glass bottles also has a certain impact on drugs. There are broken silicon-oxygen bonds on the surface of glass, which can adsorb various molecules, such as water molecules, cations, anions, organic acids with specific groups, enzymes, etc. This adsorption is mainly achieved through two mechanisms:
Ion exchange adsorption: In neutral or acidic solutions, alkali metal ions such as sodium ions in the glass are exchanged with hydrogen ions in the drug solution.
Adsorption caused by the reaction of certain groups in the drug with the glass: For example, certain groups in the drug will react with the broken Si-O bonds in the glass or adsorb with Si-OH after the adsorption of hydrogen ions through hydrogen bonds.