Holistically assessing the quality consistency of compound liquorice tablets from similarities of both all chemical fingerprints and the integrated dissolution curves by systematically quantified fingerprint method

In recent years, traditional analytical methods have failed to meet the widespread use of multi-component Chinese pharmaceutical formulations. To solve this problem, this study proposed a comprehensive analytical strategy using compound liquorice tablets (CLTs) as an example, both in terms of chemical quality and dissolution curve consistency. Firstly, the peak purity of the two wavelengths was checked using dual-wavelength absorbance coefficient ratio spectra (DARS) to avoid the fingerprint bias caused by peak purity. Secondly, liquid-phase dual-wavelength tandem fingerprint (DWTF) of 38 batches of CLTs was established for the first time. The two analytical methods were also evaluated using the systematically quantified fingerprint method (SQFM), and the 38 batches of samples were classified into two grades with good quality consistency. Quantitative analysis of the five markers of CLTs was performed simultaneously using the standard curve method (SCM) and the quantitative analysis of multiple components by single marker (QAMS). The results showed no significant differences between the two analytical methods (p > 0.5). In addition, the in vitro dissolution of CLTs in two media (pure water and pH = 4.5 medium) was determined by the total UV fingerprint dissolution assay. The similarity of the dissolution curves was also analyzed by combining the f2 factor and the dissolution-systematically quantified fingerprint method (DSQFM). The result showed that most of the samples had f2 > 50 and Pm satisfied the range of 70-130%. Finally, a principal component analysis (PCA) model was developed to combine the evaluation parameters of chemical fingerprint and dissolution curves for comprehensive analysis of the samples. In this study, a chromatographic and dissolution-based quality analysis method was proposed, which effectively overcomes the shortcomings of previous analytical methods and provides a scientific analytical method for the quality control of natural drugs.