Abstract: Objective To investigate the similarity of Pule’an tablets and the content of their marker compound, kaempferol. Methods The tablets were extracted with 70% ethanol before being concentrated under reduced pressure to afford crude extracts (CRs) that were then extracted with petroleum ether and ethyl acetate (EA) respectively. The analytical data including quantitative ¹H-NMR and LC-MS of the extract portion EA was collected. In order to find out about the batch-to-batch consistency of the samples, the cosine similarity calculation method was used to calculate the pre-processed data. Methyl 3,5-dinitrobenzoate was selected as the internal calibrant (IC) to calculate the content of kaempferol in Pule’an tablets using the qNMR method. Results The ¹H-NMR similarity of the 9 batches of Pule’an tablets was determined to be 0.984, while LC-MS similarity was 0.987. Using the internal calibration method of quantitative NMR, the content of kaempferol in the samples was measured to range from 2.03 mg to 12.86 mg per tablet. Conclusion The results suggest that the similarity between the 9 batches of Pule’an tablets is high, which can help guarantee the efficacy and safety of the product. The IC-qHNMR method used for content determination of kaempferol is user-friendly, fast, and accurate.

Key words: Pule’an Tablets, Kaempferol, Methyl 3,5-Dinitrobenzoate, ¹H-NMR, LC-MS, Cosine Similarity