Identification Test of the Ibuprofen Active Ingredient Compliant with European Pharmacopoeia and United States Pharmacopeia and Analysis of Final Product (Commercial Pharmaceutical) by ATR Method

Significance of the Topic

Infrared spectroscopy is a cornerstone technique in pharmaceutical analysis for the identification of active ingredients and finished products. Ibuprofen is a widely used nonsteroidal anti inflammatory drug whose quality control is governed by regional pharmacopeial standards. Reliable compliance with the European Pharmacopoeia and the United States Pharmacopeia ensures product safety and efficacy.

Objectives and Study Overview

This study evaluated identification tests for ibuprofen active substance and a commercial tablet using a Fourier Transform Infrared spectrophotometer of the IRSpirit X series. The goals were to apply European Pharmacopoeia compliant KBr pellet and ATR methods, United States Pharmacopeia compliant paste method, and to compare spectral differences arising from each approach.

Methodology and Instrumentation Used

The analysis employed an IRSpirit ZX FTIR spectrophotometer equipped with a diamond ATR attachment (QATR S) and a DLATGS detector. Measurement parameters included 2 cm-1 resolution, 45 scans per spectrum, and wavenumber ranges of 4000 to 550 cm-1 for EP methods and 3800 to 650 cm-1 for USP NF methods. A hydraulic press formed 7 mm diameter KBr pellets. Software control and data processing were performed with LabSolutions IR and the IR Pilot identification module.

Main Results and Discussion

The KBr pellet method produced spectra of test and reference ibuprofen samples that matched across characteristic absorption bands. ATR spectra exhibited similar features but showed slight shifts in strong peaks near 1700 cm-1 due to refractive index and penetration depth effects. The paste method generated spectra influenced by absorption bands of the mineral oil medium. Overlay comparisons confirmed that each technique reliably identifies ibuprofen provided that test and reference samples are measured under identical conditions.
Surface ATR measurement of a commercial tablet coating identified cellulose and talc components by library matching, while analysis of ground tablet powder overlaid with the ibuprofen reference spectrum revealed additional ingredients. Difference spectra and library searches detected caffeine and silicate in the formulation.

Benefits and Practical Applications

• The IRSpirit ZX model offers high sensitivity and humidity resistance in a compact design suitable for space-limited laboratories.
• Multiple sampling methods accommodate diverse pharmacopeial requirements for active ingredients and finished products.
• Automated workflows via the IR Pilot module simplify sample measurement, data analysis, and report generation.

Future Trends and Opportunities

Emerging developments may include integration of rapid ATR imaging, expanded spectral libraries with automated chemometric identification, and portable FTIR systems for at-line quality control. Further progress in quantitative FTIR modelling and multivariate calibration will enhance throughput and analytical robustness in pharmaceutical laboratories.

Conclusion

This work demonstrates that EP and USP NF identification tests for ibuprofen can be effectively conducted using the IRSpirit X series FTIR platform. Consistent use of the same measurement technique for test and reference samples is essential to avoid spectral discrepancies. The instrument’s durability, compact form factor, and software automation support efficient routine analysis in pharmaceutical quality control.

References

1. European Pharmacopoeia Supplement 11.2 2023
2. United States Pharmacopeia-National Formulary 2023 Issue 2
3. Rastogi A et al Journal of Environmental Management 300 113694 (2021)
4. FTIR Talk Letter Vol 1
5. FTIR Talk Letter Vol 2
6. FTIR Talk Letter Vol 38