Analysis of Residual solvents USP 467 Class 2 MixB in pharmaceuticals

Importance of the Topic

Accurate determination of residual solvents in pharmaceuticals is essential to ensure patient safety and regulatory compliance. Gas chromatography with headspace sampling offers high sensitivity and selectivity for volatile compounds. The use of a polar wax phase column enhances separation of water-soluble and polar solvents, making it a valuable tool in quality control laboratories.

Objectives and Study Overview

This application note evaluates the performance of a GC-2010 Plus system equipped with an HS-20 headspace sampler and an SH-PolarWax column for analysis of eight Class 2 residual solvents in pharmaceuticals according to USP 467 Procedure B. The goal is to demonstrate separation, peak shape, and reproducibility under specified conditions.

Methodology and Instrumentation

The system configuration included:

• Gas chromatograph: Shimadzu GC-2010 Plus
• Headspace sampler: HS-20
• Column: SH-PolarWax, 30 m × 0.32 mm I.D., 0.25 μm film
• Carrier gas: Helium at 35 cm/s linear velocity
• Oven program: 50 °C hold 20 min, ramp 6 °C/min to 165 °C, hold 20 min
• Headspace conditions: 80 °C equilibrium for 60 min, 75 kPa vial pressure, 20 mL vial volume
• Detector: Flame ionization at 250 °C with H2 40 mL/min, air 400 mL/min, He make-up 30 mL/min

Key Results and Discussion

All eight solvents (hexane, 1,2-dimethoxyethane, trichloroethene, chloroform, methylbutylketone, nitromethane, pyridine, tetraline) were baseline-resolved. Retention times increased in polarity order, and peak symmetries met USP acceptance criteria. The polar wax phase reduced coelution of polar analytes and provided consistent response factors.

Benefits and Practical Applications

• Regulatory compliance: Fulfills USP 467 requirements for Class 2 residual solvents.
• Enhanced separation: Effective resolution of both nonpolar and polar compounds.
• Operational robustness: Stable performance supports high-throughput QC environments.

Future Trends and Potential Applications

Integration with mass spectrometric detection could lower detection limits and increase specificity. Automated sample handling and real-time monitoring through process analytical technology (PAT) frameworks may further streamline residual solvent analysis in pharmaceutical manufacturing.

Conclusion

The described GC-HS-FID method on an SH-PolarWax column offers a validated, reliable approach for quantifying Class 2 residual solvents in compliance with USP 467 Procedure B, supporting rigorous pharmaceutical quality control.

References

USP 467 Pharmaceutical Residual Solvents; Shimadzu Corporation, ERAS-1000-0490, First Edition Sep. 2023