Evaluating the quality consistency of Keteling capsules by three-dimensional quantum fingerprints and HPLC...

Keteling capsules (KCs), as a kind of Traditional Chinese Medicine (TCM), have been widely used in curing cough and relieving asthma. However, the complicated compositions make it challenging to evaluate their quality consistency by common methods. Herein, we explored comprehensive and efficient strategies by combining the multiple techniques to monitor and assess the characteristics of KCs. We employed the fingerprints and corresponding quantum fingerprints by fourier transform infrared spectroscopy (FT-IR), ultraviolet (UV), and differential scanning calorimetry (DSC). The antioxidant activity profiles were also studied combined with the result of three-dimensional quantum fingerprints and showed a good correlation with the internal structure and physical-chemical state. Furthermore, the 17 samples were separated and identified simultaneously by HPLC quantitative fingerprint, of which four active ingredients (chlorogenic acid, p-coumaric acid, vitexin and isovitexin) were quantitatively determined. The 17 samples were successfully classified into different grades by the systematically quantified fingerprint method (SQFM) and the quality of the samples was integrated according to the mean algorithm. The mean algorithm fusion of different evaluation techniques was compared to reveal the relationship between them, which indicated the effective improvement in accuracy and integrality. The combination of multiple analytical techniques developed in this study would effectively improve the existing single analytical methods and provide new strategy for drug quality consistency control.