Screening of Nitrosamine Impurities in Drug Products and Drug Substances Using Agilent GC/MS/MS Instrumentation

Significance of the Topic

Trace levels of nitrosamine impurities in pharmaceuticals have emerged as a critical safety concern due to their carcinogenic potential. Regulatory agencies such as the FDA and EMA require risk-based assessments and confirmatory testing to ensure patient safety and product compliance.

Goals and Study Overview

This application note presents a generic screening method for 13 nitrosamines in drug substances and products using GC/MS/MS. The approach aims to detect and estimate impurities at trace levels, providing an initial screening tool for marketing authorization holders following risk evaluations.

Methodology

Sample preparation varies with solubility: solid samples are dispersed in methylene chloride, while water-soluble matrices undergo alkaline extraction followed by liquid-liquid partitioning into methylene chloride. Deuterated internal standards (NDMA-d6, NDEA-d10, NDIPA-d14, NDBA-d18) ensure accurate quantification. Calibration spans 1–60 ppb (depending on analyte), with linearity assessed by r ≥0.98. Limit of detection (LOD) values range from 0.05 to 2 ppb, and limits of quantification (LOQ) from 1 to 10 ppb.

Used Instrumentation

• Agilent 8890 Gas Chromatograph with splitless injection
• Agilent 7693A Automatic Liquid Sampler
• Agilent 7010B Triple Quadrupole GC/MS/MS with High-Efficiency Source
• Agilent J&W DB-1701 capillary column (30 m × 0.25 mm, 1.0 μm film)
• Helium carrier gas, electron ionization at 70 eV

Main Results and Discussion

Chromatographic separation of all 13 nitrosamines was achieved without cross-talk. Recovery studies at multiple spike levels (1–60 ppb) showed accuracy between 70–130% and repeatability RSD <20%. Calibration curves were linear (r =1.00), and sensitivity allowed confident screening. Both direct dispersion and aqueous extraction protocols yielded comparable performance. Instrument diagnostics and touch-screen control facilitated routine operation.

Benefits and Practical Applications

This method provides a fast, generic screening workflow to confirm the presence or absence of nitrosamine impurities in drug products and substances. It supports regulatory risk assessments, batch testing, and informs confirmatory method development when positive findings arise.

Future Trends and Potential Applications

Advancements may include expansion to additional nitrosamine analogues, integration of high-resolution MS for enhanced selectivity, automated sample preparation systems, miniaturized platforms for on-site testing, and application to biologics and environmental monitoring.

Conclusion

The Agilent 8890 GC coupled with the 7010B GC/MS/MS demonstrates robust performance for trace-level screening of 13 nitrosamine impurities. With low detection limits, high accuracy, and reliable repeatability, this method offers an effective tool for pharmaceutical quality control and regulatory compliance.

References

• EMA/369136/2020 EMEA Assessment Report on Nitrosamines.
• EMA/409815/2020 Q&A for Marketing Authorization Holders on Nitrosamine Impurities.
• FDA Guidance: Control of Nitrosamine Impurities in Human Drugs.