Abstract: 〔Abstract〕Objective：To study the plasma concentration and pharmacokinetics of 3，29-dibenzoyl-karounitriol （3，29-DK）in Gualou-Xiebai intragastric floating pellets （hereinafter referred to as "Gualou-Xiebai pellets"）at different time points in rats by liquid chromatography tandem mass spectrometry （LC-MS/MS）. Methods：12 SPF SD male rats were randomly divided into
Gualou- Xiebai pellets group（2.0 g/kg）and Gualou-Xiebai extracts group（1.4 g/ kg），the blood samples were taken from the orbit 0 h before administration and 0.5，1，2，3，4，6，8，10，12，24，36，48 h after administration in Gualou-Xiebai pellets group，the blood samples were taken from the orbit 0 h before administration and 5，10，30 min，1，1.5，2，3，4，6 and 8 h after administration in the Gualou-Xiebai extracts group，and the pharmacokinetic parameters were calculated. Results：Compared with the Gualou-Xiebai extracts group，the 3，29-DK peak time，AUC and t 1/2 in the Gualou-Xiebai pellet group were significantly prolonged（P<0.05），and MRT was significantly increased（P<0.05），CLz/F，C max was significantly reduced（P<0.05）. Conclusion： The release rate of 3，29-DK in Gualou-Xiebai pellets was stable in rats，without sudden release and rapid release，and the metabolic time was prolonged. Gualou-Xiebai pellets have sustained-release effect.

Key words: 〔Key words〕LC-MS/MS；Gualou-Xiebai intragastric floating pellets；3, 29-dibenzoyl-karounitriol；pharmacokinetics