About PermaSure+ and the world’s first Ph. Eur. 5.24 compliant FT-IR imaging

Significance of the Topic

Chemical imaging by FT-IR microscopy delivers spatially resolved molecular information critical for fields such as pharmaceutical manufacturing, materials science and quality control.
Despite its potential, reliable calibration and quantitative exploitation of image data remained challenging until the introduction of a harmonized guideline in the European Pharmacopoeia (Ph. Eur.) chapter 5.24.

Objective and Overview of the Study

This application note describes how Bruker’s novel PermaSure+ pixel-by-pixel laser calibration enables the first FT-IR imaging system compliant with Ph. Eur. 5.24 requirements.
Authors Dr. Oliver Maute and Dr. Simon Schrindwein explain the standard’s recommendations, the technical hurdles in meeting wavenumber accuracy for each detector pixel, and Bruker’s solution implemented in the LUMOS II microscope.

Methodology and Instrumentation

Ph. Eur. 5.24 calls for accurate spectral axis calibration comparable to single-element spectrometers.
Bruker tackled pixel-specific path length variations inside the interferometer by integrating PermaSure+ ― a laser-based routine that assigns precise wavenumber and intensity values to every array pixel.
Key instrumentation features:

• LUMOS II FT-IR imaging microscope with focal plane array detector
• PermaSure+ pixel-by-pixel laser calibration module
• High-speed data acquisition (>900 spectra/s)

Main Results and Discussion

Without PermaSure+, the water vapor band peak positions varied by several wavenumbers across pixels, violating Ph. Eur. 5.24 tolerances.
After calibration, the pixel-to-pixel variance collapsed to levels indistinguishable from single-element detectors, ensuring full compliance.
The improved x-axis accuracy supports both qualitative imaging and quantitative analysis across the entire field of view.

Benefits and Practical Applications

PermaSure+ compliance unlocks robust deployment of FT-IR imaging in regulated environments:

• Pharmaceutical quality control: validated particle mapping, coating uniformity checks
• Materials research: defect analysis, polymer characterization
• Process monitoring: real-time distribution of active ingredients

Future Trends and Applications

Emerging directions include coupling FT-IR imaging with automated sample handling, AI-driven spectral classification and extension into hyperspectral and Raman modalities under common validation frameworks.
Integration with manufacturing execution systems will foster inline quality assurance and predictive maintenance.

Conclusion

Bruker’s PermaSure+ innovation represents a milestone in FT-IR imaging by delivering Ph. Eur. 5.24 compliance through pixel-level calibration.
This advancement broadens the technology’s applicability in regulated sectors and paves the way for future multimodal chemical imaging solutions.

Reference

European Pharmacopoeia Chapter 5.24: ‘‘Guidelines on chemical imaging techniques for pharmaceutical analysis.’"