Qualitative and quantitative analyses of Tripterygium hypoglaucum in Yinning Tablets, a compound traditional Chinese herbal preparation

Abstract

To conduct qualitative and quantitative analyses of Tripterygium hypoglaucum in Yinning Tablets, a compound preparation of traditional Chinese herbal medicine. Thin-layer chromatography (TLC) was used for qualitative analysis of Tripterygium hypoglaucum in Yining Tablets and the analytical protocols were optimized. High-performance liquid chromatography (HPLC) was used to quantitatively analyze the content of triptolide (the main active ingredient of Tripterygium hypoglaucum) in Yinning Tablets. The results of TLC analysis showed that the test sample of Yinning Tablets and the positive control samples both produced clear, well separated spots without obvious interference in the blank samples. Assessment of the influences of the thin-layer plates from different manufacturers, temperature and humidity on the test results demonstrated good durability of the test. HPLC analysis of triptolide showed a good linear relationship within the concentration range of 1-100 μg/mL (regression equation: A=22.219C-19.165, r=0.9999); the contents of triptolide in 3 batches of Yinning tablets were 0.34, 0.34, and 0.28 μg per tablet, all within the range of 0.28-0.34 μg per tablet. It was finally determined that each Yinning tablet should not contain more than 0.6 μg of triptolide. TLC and HPLC are simple, accurate, durable and specific for qualitative and quantitative analyses of Tripterygium hypoglaucum in Yinning Tablets.