Determination of UV Filters in Sunscreens Using Agilent Captiva EMR—Lipid Cleanup by HPLC

Significance of the Topic

Sunscreens rely on UV‐absorbing compounds to prevent sunburn and DNA damage. Accurate quantification of these filters ensures product safety, regulatory compliance, and consistent performance. The high lipid content in sun care matrices poses chromatographic challenges and risks system contamination without effective cleanup.

Study Objectives and Overview

This work develops and validates a robust HPLC method for quantifying five FDA‐approved UV filters in over‐the‐counter sunscreens and a lip balm. Key aims include streamlining sample preparation, removing lipid interferences, and demonstrating reproducible performance across multiple commercial products.

Methodology

• Sample Extraction: 100 mg of product mixed with hot water (85–95 °C) and isopropanol, followed by vortexing, sonication, and centrifugation.
• Lipid Cleanup: Supernatant passed through Agilent Captiva EMR‐Lipid cartridges to selectively remove matrix lipids.
• Post‐Cleanup Filtration: Eluate filtered using 0.2 µm glass fiber/nylon syringe filters into amber vials prior to injection.

Used Instrumentation

• Agilent 1260 Infinity II LC system with quaternary pump, vacuum degasser, autosampler, and column heater.
• Diode Array Detector set at 238 nm.
• Agilent InfinityLab Poroshell 120 EC‐C18 column (3.0×50 mm, 2.7 µm) with guard column.
• Agilent Captiva EMR‐Lipid 6 mL cartridges.

Main Results and Discussion

Direct injection of crude extracts led to retention time drift, baseline shifts, peak shape distortion, and column fouling after only six matrix injections. Incorporation of EMR‐Lipid cleanup restored excellent baseline separation of six analytes, with retention time RSD ≤ 0.11% and peak area RSD < 0.41%. Calibration curves were linear (R² > 0.999) over 0.125–2 mg/mL. Recoveries across seven products ranged from 95.0 to 103.5% with RSD ≤ 2.19%. The method enabled over 600 injections on the same column without performance loss.

Benefits and Practical Applications

• Enhanced chromatographic reproducibility and peak integrity in complex cosmetic matrices.
• Extended column lifetime and reduced maintenance costs.
• High accuracy and recovery suitable for regulatory QA/QC testing.
• Applicable to diverse personal care formulations.

Future Trends and Potential Applications

Future developments may include integration of automated EMR‐Lipid cleanup modules, coupling with mass spectrometry for expanded analyte panels, adoption of greener solvents, and application to broader cosmetic or pharmaceutical matrices.

Conclusion

The Agilent Captiva EMR‐Lipid cleanup combined with HPLC‐DAD provides a reliable, accurate, and high‐throughput solution for UV filter analysis in sunscreen products. This workflow minimizes matrix interferences, safeguards column performance, and supports regulatory and quality control demands.

References

1. U.S. FDA Center for Drug Evaluation and Research. Labeling and Effectiveness Testing: Sunscreen Drug Products for Over-the-Counter Human Use—Small Entity Compliance Guide; 2019.
2. U.S. FDA. Sunscreen: How to Help Protect Your Skin from the Sun; 2019.
3. Joseph S.; Woodman M. Agilent 1290 Infinity LC with Agilent Poroshell Columns for Simultaneous Determination of Eight Organic UV Filters in under Two Minutes. Agilent Technologies Application Note; 2010.