Knowledge popularization of medicinal glass

The main composition of glass is quartz (silica). Quartz has good water resistance (that is, it hardly reacts with water). However, due to the high melting point (about 2000°C) and high price of high-purity silica, it is not suitable for use Mass production; Adding network modifiers can lower the melting point of the glass and lower the price. Common network modifiers are sodium, calcium, etc.; but the network modifiers will exchange hydrogen ions in the water, reducing the water resistance of the glass; adding boron and Aluminum can strengthen the glass structure, the melting temperature has risen, but the water resistance has been significantly improved.

Pharmaceutical packaging materials can directly contact drugs, and their quality will affect the safety and stability of the drugs. For medicinal glass, one of the main criteria for its quality is water resistance: the higher the water resistance, the lower the risk of reaction with drugs, and the higher the glass quality.

According to the water resistance from low to high, medicinal glass can be divided into: soda lime glass, low borosilicate glass and medium borosilicate glass. In the Pharmacopoeia, glass is classified into Class I, Class II, and Class III. Class I high-quality borosilicate glass is suitable for the packaging of injection drugs, and Class III soda lime glass is used for the packaging of oral liquid and solid drugs, and is not suitable for injection drugs.

In the past, low borosilicate glass and soda-lime glass were still used in domestic pharmaceutical glass. According to the “In-depth Research and Investment Strategy Report on China’s Pharmaceutical Glass Packaging (2019 Edition)”, the use of borosilicate in domestic pharmaceutical glass in 2018 only accounted for 7-8%. However, since the United States, Europe, Japan, and Russia all mandate the use of neutral borosilicate glass for all injection preparations and biological preparations, medium borosilicate glass has been widely used in the foreign pharmaceutical industry.

In addition to classification according to water resistance, according to different manufacturing processes, medicinal glass is divided into molded bottles and controlled bottles. The molded bottle is to directly inject the glass liquid into the mold to make a medicine bottle; while the control bottle is to first make the glass liquid into a glass tube, and then cut the glass tube to make the medicine bottle

According to the Analysis Report of the Industry of Glass Packaging Materials for Injections in 2019, injection bottles accounted for 55% of the total pharmaceutical glass and are one of the main products of pharmaceutical glass. In recent years, the sales of injections in China have continued to increase, driving the demand for injection bottles to continue to rise, and changes in injection-related policies will drive changes in the pharmaceutical glass market.