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Transmission fourier transform Raman spectroscopy of pharmaceutical tablet cores
Michael J Pelletier1, Peter Larkin, Matthew Santangelo
1Analytical Technology, Pharmaceutical Sciences, Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, USA. michael.pelletier@pfizer.com
Applied Spectroscopy
|March 28, 2012
Summary
Transmission Fourier transform (FT) Raman spectroscopy offers enhanced precision for pharmaceutical tablet analysis compared to backscattering methods. While self-absorption can cause spectral distortions, key pharmaceutical regions show minimal impact, enabling reliable analysis.
Area of Science:
- Analytical Chemistry
- Pharmaceutical Analysis
- Spectroscopy
Background:
- Raman spectroscopy is a valuable technique for analyzing pharmaceutical formulations.
- Traditional backscattering Raman spectroscopy has limitations in precision and sample volume.
- Transmission Fourier transform (FT) Raman spectroscopy presents an alternative approach.
Purpose of the Study:
- To demonstrate the application of transmission FT Raman spectroscopy for pharmaceutical tablet core analysis.
- To evaluate the precision benefits of transmission FT Raman spectroscopy over backscattering methods.
- To investigate the impact of self-absorption on spectral data and probe volume.
Main Methods:
- Utilized unmodified commercial instrumentation for transmission FT Raman spectroscopy.
- Acquired spectra from pharmaceutical tablet cores.
- Surveyed near-infrared (NIR) absorption spectra of relevant molecules.
- Performed statistical analysis of spectral noise and self-absorption effects.
Main Results:
- Transmission FT Raman spectroscopy demonstrated improved precision due to increased sample volume compared to backscattering.
- Self-absorption effects were observed, influencing analyte band ratios and probe volume.
- Key pharmaceutical spectral regions (0–600 cm⁻¹ and 1400–1900 cm⁻¹) showed low self-absorption for most organic materials.
Conclusions:
- Transmission FT Raman spectroscopy is a viable technique for pharmaceutical tablet analysis with enhanced precision.
- Understanding and accounting for self-absorption is crucial for accurate spectral interpretation.
- The method provides valuable insights into spectral distortion and sampling volume limitations.
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