Production of pharmaceutical glass packaging containers

As an important member of pharmaceutical packaging materials, glass packaging has withstood the test of time, meeting the vast majority of requirements from the early stages of drug development (such as physical and chemical properties, pharmaceutical compatibility, etc.), through production scale-up (process adaptability, etc.), to clinical trials and market launch (safety, etc.). Despite its long history, however, there is still a lack of understanding about glass packaging materials among pharmaceutical professionals or packaging professionals to some extent. Therefore, we will share knowledge with you based on industry literature and reviews, hoping it will be helpful to everyone.

I. The production process of pharmaceutical glass

The production process of pharmaceutical glass can be divided into two parts: obtaining the glass melt based on the glass formula, and shaping the glass melt into glass containers through different methods. The former is analogous to the process of producing flour (from wheat and other additives), while the latter is akin to the process of making steamed buns (transforming flour into steamed buns through various methods). For pharmaceutical glass, the biggest difference from other types of glass lies in its formula and the strict control over raw materials and production processes (due to its pharmaceutical use, which requires relatively stringent standards). Then, different processes are used to convert pharmaceutical glass into containers. Below, starting from the basics, I will introduce the entire production process.

II. The raw materials for glass production

The raw materials for glass production are, colloquially speaking, sand (primarily composed of silicon dioxide) and other mineral raw materials (including elements such as boron, sodium, potassium, etc.). These are melted in a high-temperature furnace. Depending on the process, if it is for molded bottles, the molten glass is poured into molds for shaping; if it is for tubular bottles, the molten glass is first drawn into hollow glass tubes, which are then processed into tubular bottles on a later forming machine.

Figure 1: Preparation of Glass Melt

III. The processes for molded bottles and tubular bottles
The processing processes for molded bottles and tubular bottles are shown in Figure 2.

Figure 2: Production Process of Molded and Tubular Bottles

Explanation:
-1-2 represents the diagram and process for the production of molded bottles.
-3-4 represents the diagram and process for the production of tubular bottles.

Ⅳ. The differences between molded bottles and tubular bottles

Due to the differences in the aforementioned processes, there are some distinctions in certain functional aspects between the tubular bottles and molded bottles obtained, as shown in Figure 3.

Item	Tubular Bottles	Molded Bottles
Wall Thickness & Uniformity	Very consistent wall thickness	Consistent (but more difficult to maintain due to process reasons)
Chemical Resistance	Higher chemical resistance	Lower chemical resistance
Manufacturing Process	Produced by drawing glass tubes and then processing	Produced by pouring molten glass into molds (making it difficult to control shape and precision, especially inner
Process precision	The dimensions and shapes can be controlled very consistently due to the manufacturing process of first producing glass tubes and then processing	It is difficult to control the shape and precision (especially the inner surface
Optical Transparency	Very uniform and transparent	Large differences in optical transmittance
Thermal Stability	Higher thermal stability	Lower thermal stability

                Figure 3: Comparison of Tubular Bottles and Molded Bottles.

Explanation:

 - The two on the left are tubular bottles, and the one on the right is a molded bottle.

- Tubular bottles have uniform transparency, while molded bottles have uneven light transmission and distortion.

Ⅴ. Conclusion

l  Pharmaceutical glass bottles are divided into tubular bottles and molded bottles.

l  Compared to molded bottles, tubular bottles have certain advantages in terms of transparency and thermal stability.