Analysis of Paeonol in Six Ingredient Pills with Rehmannia

Significance of the Topic

Paeonol is a key phenolic component in the widely used traditional formulation Six Ingredient Pills with Rehmannia. Accurate measurement of this compound is essential to guarantee batch‐to‐batch consistency, safety, and efficacy of herbal products.

Objectives and Study Overview

This work aimed to develop and validate a reversed‐phase HPLC method for precise quantification of paeonol in Six Ingredient Pills with Rehmannia. The study focused on optimizing the extraction procedure and chromatographic parameters to achieve reliable recovery and peak resolution.

Methodology and Instrumentation

Samples were ground to a fine powder, and 0.7 g was extracted by refluxing in 50 % methanol/water for 1 hour. After cooling and volume adjustment, the extract was filtered before injection.

A Shim-pack GIS C18 column (250 × 4.6 mm, 5 μm) was used with a binary mobile phase: A—0.3 % phosphoric acid, B—acetonitrile. The gradient program was:

1. 5 % B at 0.0 min
2. 8 % B from 5.0 to 20.0 min
3. 20 % B at 35.0 min
4. 60 % B from 45.0 to 55.0 min
5. Return to 5 % B at 55.1 min and hold to 65 min

Flow rate was 1.3 mL/min, column temperature 40 °C, detection at 274 nm, injection volume 10 µL.

Main Results and Discussion

Chromatograms of standard mix (45 µg/mL paeonol) and sample extracts displayed a single, sharp paeonol peak with consistent retention time and baseline resolution. No significant interferences from herbal matrix components were observed.

Benefits and Practical Applications

This validated method offers high sensitivity and reproducibility for routine quality control of herbal formulations. Its straightforward sample preparation and clear chromatographic separation make it suitable for pharmaceutical and nutraceutical laboratories.

Future Trends and Applications

Integration with mass spectrometric detection can enhance specificity and enable multi‐component profiling. Adoption of shorter columns and greener solvents will further increase throughput and reduce environmental impact.

Conclusion

A robust reversed‐phase HPLC method employing Shim-pack GIS C18 was established for reliable quantification of paeonol in Six Ingredient Pills with Rehmannia, supporting stringent quality assurance in herbal medicine production.

Reference

Shimadzu Corporation (2023) Analysis of Paeonol in Six Ingredient Pills with Rehmannia, Application Note ERAS-1000-0003.