NIR Technology: A Non-Destructive Alternative for Lyo Defect Detection

Near Infrared Spectroscopy (NIRS) is a non-destructive, efficient, and environmentally friendly method, which is transforming quality control for lyophilized products, offering advantages over traditional techniques like visual inspection and Karl Fischer Titration.

What is Near Infrared Spectroscopy?

NIRS is an analytical technique that uses the near-infrared region of the electromagnetic spectrum (780 – 2500 nm) to analyze substances. By observing the overtones and vibrational combinations of molecular bonds such as OH-, NH-, SH- and CH-, NIRS can detect subtle changes in a product’s composition or structure.

This versatile method is widely applied across industries such as pharmaceuticals, food, and beverages, offering flexible deployment options including off-line, at-line, and in-line setups.

Why NIR Inspection Matters

For lyophilized products, residual moisture is a critical quality attribute that impacts long-term stability. Traditional methods like Karl Fischer Titration require sample destruction, limiting their utility for 100 % inspection. Other surface-level defects, such as meltbacks or shrunken cakes, may be identified visually, but this approach is limited in accuracy and scope.

NIR spectroscopy bridges these gaps, providing a comprehensive, non-destructive solution for inspecting lyophilized products.

How NIRS Works in Lyophilized Product Inspection

The NIR inspection process involves illuminating a vial of lyophilizate with a tungsten halogen lamp. Light is scattered from the lyophilizate. The scattered light is captured via an optical fiber and directed to a diode array spectrometer. This digitized output is analyzed to detect moisture concentration and other parameters.

With its ability to detect subtle changes in cake conditions more sensitively than visual systems, NIRS has become an ideal method for identifying meltback defects and other internal inconsistencies in lyophilized products.

NIR as an Alternative to Visual Inspection

Traditional quality control methods for lyophilized products, such as manual visual inspections, often fall short due to human variability or technological limitations. These approaches can result in high rejection rates and missed defects.

NIRS offers an automated, accurate alternative, capable of detecting defects within the cake without disrupting its structure. By leveraging chemometric models validated with known defect samples, NIRS ensures reliable and repeatable results.

The WILCO Advantage: SPECTRA NIV for High-Speed NIR Inspection

Our SPECTRA NIV platform exemplifies the power of NIRS for lyophilized product inspection.

This high-speed system delivers unparalleled benefits:

• Non-destructive Inspection: Preserves product integrity.
• Rapid Results: Measurement results below one second.
• Environmentally Friendly: No sample preparation or chemical waste.
• High Throughput: Capable of inspecting up to 600 vials per minute.
• Comprehensive Analysis: Simultaneously detects moisture levels, structural defects, and product identity.
• Automated and Reliable: Minimizes human intervention and delivers results comparable to established methods like Karl Fischer Titration.

Case Study: Solving Cake Defect Challenges

A customer approached us with concerns about lyo cake defects caused by humidity variations during the freeze-drying process. These defects, while not always visible, posed risks to product reliability and aesthetics.

Using NIRS, we developed and validated a chemometric model to classify defective cakes accurately. The resulting automated inspection platform ensured 100 % non-destructive testing at production speeds, significantly improving quality control outcomes.

Read more about the case study here.

The Future of Lyophilized Product Inspection?

As regulatory requirements tighten and demand for higher-quality products grows, Near Infrared Spectroscopy is emerging as the gold standard for lyophilized product inspection. With its ability to deliver precise, non-destructive, and high-throughput analysis, NIRS is setting a new benchmark in pharmaceutical quality control.

At WILCO AG, our commitment to innovation ensures we remain at the forefront of this transformative technology, providing our customers with solutions that are not only efficient but also environmentally responsible.