A simple HPLC method for simultaneous analysis of 7 bioactive constituents for Liuwei Dihuang Pill and its application in quality consistency evaluation

A combinative method using HPLC fingerprinting and quantitative analysis was developed and validated for manufacturer-to-manufacturer quality consistency evaluation of Liuwei Dihuang pills (LDP). Seven bioactive constituents of LDP, including gallic acid, 5-hydroxymethyl furfural, morroniside, paeoniflorin, sweroside, loganin and paeonal, were selected as markers to evaluate the similarities of 20 samples from 16 manufacturers. The similarity values for the 20 LDP samples were all greater than 0.92, indicating that there is a general quality consistency for different manufacturers. Additionally, the 7 selected bioactive compounds were in accordance with the compatibility principle of "the monarch drug, the ministerial drug, the adjunctive drug and the messenger drug" of Traditional Chinese Medicine (TCM) prescription and the multi components quality evaluation requirements of TCM as well. The detection and quantification limits for these 7 bioactive components were all less than 0.11 mu g mL(-1) and 0.38 mu g mL(-1), respectively. The mean recovery for all the investigated constituents was acceptable with an accuracy of 98-102%. The intra-and inter-day precisions of this method were less than 4.73%, and stability and repeatability were less than 3.23%. This method is simple and reliable, and also shows that the combination of the chromatographic fingerprint and quantitative analysis offers an efficient solution to quality consistency evaluation of herbal preparations.