ICP-OES ELEMENTAL IMPURITY ANALYSIS IN PHARMACEUTICALS

Importance of the topic

The control of elemental impurities in pharmaceutical products is essential to ensure patient safety and comply with international regulatory standards. New ICH Q3D and USP<232>/<233> guidelines define permissible daily exposure (PDE) limits for 24 elements, including arsenic, cadmium, mercury and lead. Reliable, quantitative techniques are required to replace outdated colorimetric and precipitation tests, delivering accurate results across diverse sample matrices.

Objectives and overview of the study

This white paper evaluates the performance of the Agilent 5110 ICP-OES system for direct analysis of oral drug products and raw materials under the new ICH and USP methods. The goal is to demonstrate the instrument’s ability to meet “J” value requirements for elemental impurities without extensive sample dilution or complex preparation.

Methodology and instrumentation used

The study employed the Agilent 5110 ICP-OES with a vertical torch, coupled to the Vista Chip II detector and ICP Expert software. Key methodological features include:

• Direct aspiration of organic and aqueous matrices with up to 25% total dissolved solids.
• Sample dilution (10×) of an oil-based pharmaceutical matrix in kerosene.
• Simultaneous multi-wavelength acquisition from 167 to 785 nm for interference avoidance.
• Automated Fitted Background Correction and FAST Automated Curve Fitting Technique (FACT) for spectral deconvolution.

Main results and discussion

The instrument achieved clear resolution of the Cd emission line at 226.502 nm in a complex oil matrix at 35 µg/L, exceeding the target J value of 50 µg/L after dilution. An in-method verification using two Cd wavelengths (214.439 nm and 226.502 nm) yielded consistent concentrations across triplicate measurements, confirming accuracy and robustness. Automated background fitting reduced development time and minimized analyst intervention.

Benefits and practical applications

The Agilent 5110 ICP-OES offers:

• High throughput and minimal gas consumption for routine QA/QC.
• Excellent stability on high-matrix samples without frequent torch maintenance.
• Quantitative compliance with ICH Q3D and USP<232> for oral formulations.
• Reproducible performance across laboratories and analysts.

Future trends and potential applications

Advancements may include integration with ICP-MS for ultra-trace determinations, further automation of sample handling, real-time process monitoring in manufacturing, and application of machine learning algorithms for spectral interpretation. Expansion of validated methods to dietary supplements and biologics will broaden the workflow’s applicability.

Conclusion

The Agilent 5110 ICP-OES system, with its vertical torch design, Vista Chip II detector and advanced software, meets the stringent requirements of current pharmacopeial guidelines. It delivers accurate, reliable and reproducible elemental impurity analyses in challenging pharmaceutical matrices.

Reference

• Agilent Technologies, Application Note 5991-5403EN, May 9, 2017