Precision in Every Mix – The Science of Batch Homogeneity — Where Medical Glass Begins to Take Shape

Precision in Every Mix – The Science of Batch Homogeneity

— Where Medical Glass Begins to Take Shape

In pharmaceutical glass manufacturing, every syringe starts long before the furnace—with a precisely blended batch. At SCHOTT, batch mixing isn’t just a step — it’s a science.

⚙️ Gravimetric Mixing for Consistency

Our batching system uses high-precision gravimetric mixers, accurate to ±0.3%, to weigh and feed raw materials in a strict heavy-to-light sequence. To prevent agglomeration, all powders are pre-sieved using a 200 μm mesh.

The mixture is then dynamically blended for at least 40 minutes, ensuring uniform particle distribution across the entire batch.

How Do We Validate Mixing Quality?

After mixing, Near-Infrared Spectroscopy (NIR) is used to evaluate batch homogeneity. A Relative Standard Deviation (RSD) ≤5% is required to pass — ensuring each syringe tube drawn from the batch maintains chemical and optical uniformity.

What If We Don’t Get It Right?

Poorly mixed batches can lead to:

• Localized melting defects

• Optical haze in tubing

• Chemical instability during sterilization

That’s why we treat mixing as a Critical-To-Quality (CTQ) step in our production.

✅ Key Takeaways

• Gravimetric mixers enable dosing accuracy of ±0.3%

• Pre-sieving eliminates clumps before blending

• NIR analysis confirms homogeneity with RSD ≤5%

• A well-mixed batch sets the foundation for defect-free glass

Want to learn more about our upstream precision process?
Contact us to explore SCHOTT-based OEM glass syringe solutions.

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