[Study on HPLC-characteristic chromatogram for evaluation of quality of Scutellaria Extract and influencing factors of preparations]

This work was carried out to establish and validate the specific characteristic chromatography of Scutellaria Extract and evaluate the quality of commercial Scutellaria Extract and optimize production process parameters. Scutellaria Extract and formulation samples collected from different manufacturers were analyzed using HPLC-characteristic chromatogram. The HPLC characteristic peaks were considered to be the index for the parameters optimization in preparations of Scutellaria Extract. The chemical pattern recognization was applied for the analysis of characteristic peak data. The established characteristic fingerprint method possessed a good precision, repeatability, and stability. Ten common characteristic peaks were determined and identified in the specific chromatogram of 31 batches of Scutellaria Extract and 4 batches of formulation. The process parameters influenced the characteristic peaks area significantly. The similarity analysis results showed that after removing baicalin peak, the similarity of the characteristic chromatography of 9 samples were less than 0.90, indicating that the quality of commercial Scutellaria Extract was inconsistent. Non-parametric test result showed that the relative peaks area of the number 4, 6, 7 characteristic peaks had significant differences(P<0.05), indicating the differences of the Scutellaria Extract quality were mainly reflected in the characteristic peaks 4, 6 and 7(norwogonin-7-O-glucuronide, oroxylin A-7-O-glucuronide, wogonoside, respectively). The cluster analysis accurately classified 31 extract samples and 4 formulation samples into five categories based on 10 characteristic peaks. The quality of Scutellaria Extracts was comprehensively evaluated and ranked by PCA. The result showed that the higher content of baicalin, the score value of quality(F value) was lower, and the quality of the Scutellaria Extract should be evaluated by multi-components instead of a single baicalin component. The optimized characteristic peaks method is stable and reliable. It is advantageous for the extract and formulations integrative quality control by combining the chemical pattern recognization.