The Agilent Cary 630 FTIR Spectrometer Quickly Identifies and Qualifies Pharmaceuticals

Importance of the Topic

Rapid and reliable identification of raw materials and finished products is essential in pharmaceutical quality control to prevent the use of counterfeit, contaminated, or mislabeled ingredients. Fourier transform infrared spectroscopy offers a non-destructive, fast approach to confirm identity and purity at multiple checkpoints.

Study Objectives and Overview

This study demonstrates a sensitive classification workflow combining Agilent Cary 630 FTIR spectroscopy with partial least squares–discriminant analysis to distinguish pure acetylsalicylic acid from samples contaminated with common excipients at levels down to 0.5%. The goal is to establish a robust method for routine QA/QC applications.

Methodology and Instrumentation

A compact Agilent Cary 630 FTIR spectrometer equipped with a single-reflection diamond attenuated total reflectance accessory was used. No sample preparation or grinding was required; small quantities were placed directly on the diamond sensor. Spectra were collected from 4 000 to 650 cm⁻¹, co-adding 74 scans per spectrum at 4 cm⁻¹ resolution in 30 seconds.

The calibration set comprised pure acetylsalicylic acid and mixtures spiked with corn starch, microcrystalline cellulose, or lactose monohydrate at 1–20 % w/w. Validation standards included new mixtures and unrelated excipients. Spectral preprocessing involved mean centering and a nine-point Savitzky–Golay first derivative. Partial least squares–discriminant analysis models were built separately for each excipient with cross-validation to select optimal factor numbers.

Key Results and Discussion

Each PLS-DA model clearly separated pure and contaminated classes, achieving coefficients of determination above 0.91. Combined logic settings in Agilent MicroLab software enabled a unified decision method. Application to blind validation samples yielded 100 % correct classification, reliably flagging contamination levels as low as 0.5 %. The visual pass/fail display highlights compliant materials in green and rejects in red.

Benefits and Practical Applications

• Fast, non-destructive analysis with minimal sample handling
• Portable and robust spectrometer meeting global pharmacopoeia standards
• ATR interface requires no preparation and yields high-quality spectra
• Integrated software supports regulatory compliance, data security, and automated performance checks
• Intuitive method-driven workflow reduces training and user error

Future Trends and Potential Applications

Advances may include expanding FTIR-based classification to additional active ingredients and excipients, integrating real-time process monitoring, and combining multivariate chemometrics with artificial intelligence for enhanced sensitivity. Enhanced spectral libraries and on-line sampling modules could further streamline pharmaceutical manufacturing and release testing.

Conclusion

The combination of Agilent Cary 630 FTIR spectroscopy and PLS-DA classification in MicroLab software provides a sensitive, specific, and user-friendly approach for verifying the identity and purity of pharmaceutical materials. This workflow supports regulatory requirements and can be tailored to a wide range of compounds.

References

• Higgins F, Seelenbinder J. Cary 630 FTIR Pharmacopoeia compliance; Application Note, Agilent Technologies, Inc., 2011.
• Dziki W, Doddi J. Pharmaceutical applications of mid-infrared spectroscopy in GMP compliance. Journal of GXP Compliance 2008;12:48–55.
• Long FH. Spectroscopic qualitative analysis methods for pharmaceutical development and manufacturing. American Pharmaceutical Review 2011;14.
• Higgins F, Seelenbinder J. Quantitative measurement of active pharmaceutical ingredients using the diffuse reflectance Cary 630 FTIR; Application Note, Agilent Technologies, Inc., 2011.