Simultaneous Analysis of Dipotassium Glycyrrhizinate and Tranexamic Acid

Importance of the Topic

The simultaneous determination of dipotassium glycyrrhizate (GK2) and tranexamic acid (TA) in cosmetic formulations addresses critical quality control and regulatory requirements. GK2, derived from licorice root, offers anti-inflammatory and skin-soothing properties, while TA serves as an effective skin-whitening agent and hemostatic compound. Reliable, rapid, and robust analytical methods enable manufacturers and laboratories to ensure product safety, efficacy, and compliance.

Objectives and Study Overview

This work demonstrates a high-performance liquid chromatography (HPLC) method using a photodiode array (PDA) detector for the simultaneous quantification of GK2 and TA in cosmetics. Key goals include simple sample preparation, adequate retention of the highly polar TA on a C18 column, and reliable peak identification in complex matrices.

Methodology and Instrumentation

• Instrument: i-Series LC-2050C 3D HPLC system
• Column: Shim-pack™ VP-ODS, 150 mm × 4.6 mm, 5 µm
• Mobile Phase: Gradient of 100 mM NaClO₄ in 10 mM phosphate buffer (pH 2.6) and 100 mM NaClO₄ in acetonitrile
• Flow Rate: 1.0 mL/min, Column Temperature: 40 °C
• Detection: PDA at 250 nm for GK2 and 220 nm for TA
• Injection Volume: 5 µL

Main Results and Discussion

Peak tailing of TA was effectively suppressed by incorporating sodium perchlorate into the mobile phase, allowing adequate retention on C18 stationary phase. Mixed standard injections (200 mg/L GK2; 4,000 mg/L TA) produced sharp, well-resolved peaks. Repeatability studies (n=5) yielded %RSD below 0.1 for TA retention time and below 0.06 for GK2. Calibration curves were linear across the tested ranges, with r² ≥ 0.9999 for both analytes. Analysis of a commercial lotion (10-fold dilution, filtration) confirmed accurate identification via retention time and UV spectra, with recoveries of 98.1% for GK2 and 97.7% for TA.

Benefits and Practical Applications

• Fast, reliable quantification of two active cosmetic ingredients in a single run
• Minimal sample preparation—dilution and filtration only
• PDA detection enhances peak confirmation even in complex matrices
• Robust method suitable for routine QC labs and regulatory testing

Future Trends and Potential Applications

Advances in column chemistries and detector technologies may further reduce analysis time and improve sensitivity. Coupling this approach with mass spectrometry could expand applicability to trace-level impurities and metabolites. Automation of sample handling and data processing will accelerate throughput in high-volume testing environments.

Conclusion

A straightforward HPLC-PDA method was developed for concurrent analysis of dipotassium glycyrrhizate and tranexamic acid in cosmetic products. The use of sodium perchlorate in the mobile phase overcame retention challenges, delivering reproducible, linear, and accurate results. This method is well suited for routine quality control and regulatory compliance.