Medicinal glass containers (such as penicillin bottles, ampoules, cartridges, etc.) come into direct contact with drugs, and their internal surface chemical stability directly affects the safety and effectiveness of the drugs. The evaluation of internal surface tolerance isGlass testing of drug packaging materialsOne of the core projects is mainly used to determine whether glass will undergo delamination, precipitation, or corrosion when in contact with aqueous or acidic liquids, which may lead to particle pollution or element migration risks.
At present, relevant tests are mainly conducted domestically and internationally based on standards such as the Chinese Pharmacopoeia, YBB (National Standard for Pharmaceutical Packaging Materials), USP<660>, and EP 3.2.1. Among them, Hydrolytic Resistance of Glass Particles and Surface Test for Hydrolytic Resistance are commonly used methods.
1. Particle method (powder method)
Suitable for unformed glass particles or debris. Place a certain amount of glass particles (usually 4-8 g, particle size between 425-850 μ m) in a high-pressure steam sterilizer, add an appropriate amount of purified water, and heat at 121 ℃ for 30 minutes. After cooling, titrate the alkaline substance released (calculated as Na ₂ O) and calculate the amount of alkali released per gram of sample (mg Na ₂ O/g). This method is used to determine the type of glass (such as borosilicate glass ≤ 32 μ g Na ₂ O/g in type 1).
2. Surface method (whole bottle method)
More closely related to actual usage scenarios. Take a complete medicinal glass container, inject the specified volume of injection water, seal it, and process it at 121 ℃ for 30 minutes. After cooling, measure the pH value change of the leachate or analyze the leaching amount of boron, sodium, aluminum and other elements by inductively coupled plasma mass spectrometry (ICP-MS). Some standards also require scanning electron microscopy (SEM) observation of the inner surface to assess the presence of etching, cracking, or delamination.
In recent years, with the widespread use of high-risk formulations such as biologics and high pH injections, accelerated detachment tests and long-term compatibility studies have gradually been incorporated into the internal surface evaluation system. For example, long-term storage under 40 ℃/75% RH conditions, or using simulated drug solutions for multi time point sampling analysis.
Attention: Glass containers need to be cleaned before testing to remove processing residues; The experimental water must meet the standards for injection water; All operations should be carried out in a clean environment to avoid interference from external particles.
In summary, the assessment of internal surface tolerance is not only a key step in the compliance and admission of pharmaceutical packaging materials, but also an important defense line to ensure the quality of the entire life cycle of drugs. Scientific selection of testing methods and strict control of experimental conditions are prerequisites for ensuring accurate and reliable evaluation results.