Determination of Nitrosamine Impurities and NDSRI in Anti-diabetic Drugs on Shimadzu LCMS-8060NX

Importance of the Topic

The detection and quantification of nitrosamine impurities in pharmaceuticals is essential due to their recognized carcinogenic potential. Regulatory authorities worldwide have set strict limits for these compounds in drug products, driving the need for robust, sensitive, and efficient analytical methods to safeguard patient health and comply with quality standards.

Study Objectives and Overview

This work presents the development of a streamlined LC-MS/MS methodology using atmospheric pressure chemical ionization (APCI) in multiple reaction monitoring (MRM) mode on the Shimadzu LCMS-8060NX platform. The goal was to quantify ten common nitrosamine impurities and nitrosamine-related substances in anti-diabetic drugs with minimal sample preparation and high analytical performance.

Methodology

Drug samples were weighed, crushed, and extracted in water at a ratio corresponding to 100 mg API per milliliter. After sonication and centrifugation, extracts were filtered through a 0.22 µm nylon membrane prior to injection. Calibration standards (0.1–10 ng/mL) were prepared in methanol. Chromatographic separation employed a C18 column (150 × 3.0 mm, 1.9 µm) with a 28-minute gradient of 0.1 % formic acid in water and methanol at 0.4 mL/min, 45 °C, and 10 µL injection volume. MS detection used APCI in positive-ion MRM mode, optimized for each analyte to achieve limits of quantitation (LOQ) well below regulatory thresholds.

Used Instrumentation

• Shimadzu Nexera™ XS LC-40 ultra-high-performance liquid chromatograph
• Shim-pack™ Scepter C18-120 column (150 mm × 3.0 mm I.D., 1.9 µm)
• Shimadzu LCMS-8060NX triple-quadrupole mass spectrometer with APCI interface
• LabSolutions™ and LabSolutions Insight™ software for data acquisition and analysis

Main Results and Discussion

Calibration curves for all ten nitrosamines exhibited excellent linearity (R2 > 0.999). Accuracy ranged from 92 % to 104 % and precision (RSD) was below 10 % at the LOQ for each analyte. Spiked recovery studies in two anti-diabetic drug matrices yielded recoveries between 74 % and 120 % at LOQ levels. Analysis of nine commercial samples detected N-nitrosopyrrolidine (NPYR) in two products at up to 19.4 ppb and nitroso-sitagliptin (NTTP) in several samples with concentrations as high as 170 ppb, demonstrating the method’s capability to uncover trace nitrosamines in real formulations.

Benefits and Practical Applications

• Simple sample preparation without extensive clean-up steps
• Low injection volume and rapid chromatography for high throughput
• Sensitive detection well below regulatory action limits
• Applicability to quality control and stability testing in pharmaceutical laboratories

Future Trends and Applications

Advances may include automation of sample handling, extension of the method to additional nitrosamine analogs, and integration with high-resolution mass spectrometry for enhanced specificity. Emerging regulatory requirements could drive adaptation to other drug classes and tighter detection limits, while digital data management will support streamlined compliance and reporting.

Conclusion

The APCI-MRM LC-MS/MS method on the Shimadzu LCMS-8060NX provides a robust, high-sensitivity approach for quantifying ten nitrosamine impurities in anti-diabetic drugs. Its combination of minimal sample preparation, excellent analytical performance, and adaptability to various drug products makes it a valuable tool for pharmaceutical quality assurance.

Reference

1. FDA. Nitrosamines as Impurities in Drugs – Health Risk Assessment and Mitigation Public Workshop; 2021.
2. European Medicines Agency. Nitrosamine Impurities; 2024.
3. FDA. Control of Nitrosamine Impurities in Human Drugs Guidance; 2020.
4. Health Sciences Authority (Singapore). Nitrosamine Impurities in Medicines; 2018.