Analysis of Paeoniflorin in Bazhenyimu Pill

Importance of the topic

Quality control of herbal medicines is critical to ensure both safety and efficacy. Paeoniflorin, a key monoterpene glycoside in peony root, exhibits pharmacological activity and must be accurately quantified in traditional formulations such as Bazhenyimu Pill.

Goals and overview of the study

This work aims to establish a reliable reversed-phase liquid chromatography method for the determination of paeoniflorin content in Bazhenyimu Pill. Emphasis is placed on method simplicity, reproducibility and routine applicability in quality control laboratories.

Methodology

The analytical procedure includes sample pretreatment and chromatographic analysis. Major steps are:

1. Grind the herbal pill to a fine powder.
2. Weigh 0.5 g of powder into a stoppered flask and add diluted ethanol.
3. Cap, sonicate for 40 minutes and cool.
4. Adjust the flask to its original weight with diluted ethanol.
5. Shake, centrifuge, and collect the clear supernatant for injection.

Instrumentation used

• Column: Shim-pack GIS C18 (250 x 4.6 mm I.D., 5 µm)
• Mobile phase: 0.3% phosphoric acid (A) and acetonitrile (B) in an 87:13 ratio
• Flow rate: 1.0 mL/min; Column temperature: 20 °C
• Detection: UV absorbance at 230 nm
• Injection volume: 10 µL
• Sample vials: LabTotal vial for LC/LCMS

Main results and discussion

The method produced a single, well-defined peak for paeoniflorin in both the standard and sample extracts, with consistent retention behavior. Calibration at 15 µg/mL resulted in a linear response over the tested range, demonstrating good precision and accuracy. The sample analysis confirmed the presence of paeoniflorin in the Bazhenyimu Pill matrix.

Benefits and practical applications

This protocol offers:

• Robust and reproducible quantification of target glycosides in complex herbal matrices
• Minimal solvent consumption due to isocratic elution
• Simplicity and rapid turnaround suitable for routine QA/QC in pharmaceutical and herbal product laboratories

Future trends and opportunities

Enhancement of this method could include coupling with mass spectrometry to improve sensitivity and selectivity. Adoption of greener solvents and smaller particle size columns may reduce analysis time and environmental impact. Automated sample preparation platforms could further increase throughput and reduce manual variability.

Conclusion

A straightforward and reliable liquid chromatography method was developed for the determination of paeoniflorin in Bazhenyimu Pill. The method is well-suited for routine quality control of herbal products and provides consistent, accurate results.

References

Shimadzu Corporation Application Note ERAS-1000-0004, First Edition, March 2023.