Novel applications of multi-detector HPLC systems in pharmaceutical analysis

Significance of the Topic

In pharmaceutical development and quality control, accurate detection and quantitation of extractables and leachables from polymeric materials, as well as detailed profiling of excipients such as polysorbate 80, are essential to ensure product safety and efficacy.

Study Objectives and Overview

This work presents novel UHPLC methods incorporating simultaneous charged aerosol detection (CAD) and mass spectrometry (MS) to address two key applications:

• Monitoring extractables and leachables (E/L) from materials including polyurethane, nylon, and PVC.
• Characterizing polysorbate 80 composition and its enzyme-induced degradation pathways.

Methodology and Instrumentation

The study employs a reversed-phase UHPLC system with an inverse gradient post-column to maintain constant solvent composition for CAD. Flow is split equally between CAD and single-quadrupole MS or 10:1 to CAD and Orbitrap Exploris™ 120 MS for high-resolution analysis. Key parameters include:

• Columns: Hypersil GOLD C18 (3.0×100 mm, 1.9 µm) for E/L and Accucore C18 (2.1×100 mm, 2.6 µm) for polysorbate.
• Column temperatures: 60 °C for E/L, 50 °C for polysorbate (forced-air with active pre-heating).
• Mobile phases: ammonium acetate or formate buffers in water and organic solvents; gradients tailored for sample types.
• Detection: CAD evaporation at 35–50 °C with optimized power functions; MS full scans in positive and negative modes across relevant m/z ranges.

Results and Discussion

CAD quantitation using a single surrogate standard achieved relative standard deviations of ~15% for non-volatile compounds, markedly better than UV (105%) or MS (109%). A volatility screening criterion (Q50/35 > 0.85) distinguished compounds reliably. E/L analysis detected and quantified nylon oligomers (trimers to octamers) and polyurethane fragments, with 10 of 12 peaks confirmed as non-volatile. Polysorbate profiling resolved sub-class components (sorbitan vs. isosorbide esters) and demonstrated lipase-induced hydrolysis by the appearance of free oleic acid and polyol peaks. Inverse gradient compensation provided linear calibration curves and stable detector response by efficient mixing of analytical and make-up flows.

Benefits and Practical Applications

• Streamlined E/L screening workflow with single-standard CAD quantitation and MS confirmation reduces analysis time and cost.
• Comprehensive polysorbate 80 characterization supports batch comparison, stability studies, and degradation mechanism elucidation.
• Improved quantitation accuracy and reduced uncertainty through volatility classification, inverse gradient use, and optimized flow mixing.

Future Trends and Applications

Advancements may include integration of additional detectors (e.g., light scattering), expanded high-resolution MS libraries, AI-driven data processing for rapid profiling, miniaturized systems for higher throughput, and real-time monitoring in manufacturing. Regulatory adoption of multidetector strategies will further standardize safety assessments.

Conclusion

The UHPLC platform combining CAD with single-quadrupole and high-resolution MS delivers robust, sensitive, and comprehensive analysis for pharmaceutical extractables, leachables, and excipient profiling, enhancing quality assurance and research capabilities.

References

• Groh KJ et al. (2018). Mass list for oligomers of caprolactam. Science of the Total Environment. doi:10.1016/j.scitotenv.2018.10.015
• Eckardt J et al. (2018). Screening for nonvolatile behavior in CAD. Journal of Chromatography A. doi:10.1016/j.chroma.2018.08.051
• Thermo Fisher Scientific. Application Note 1630: E/L with CAD, Single Quad MS, UV.
• Thermo Fisher Scientific. Application Note 1401 and AN 1950: E/L with CAD, HRAM MS, UV.
• Thermo Fisher Scientific. Application Note 73979: Polysorbate with CAD, SQ MS, UV.