Analysis on intestinal absorption of paeoniflorin lipid liquid crystalline nanoparticles via everted intestinal sacs

To study the absorption kinetics of paeoniflorin lipid liquid crystalline nanoparticles (Pae-LLCN) in different intestinal segments of rats and compare them with paeoniflorin(Pae) solution. Rat everted gut sac models were adopted for intestinal absorption test, and Pae content was determined by HPLC method to study the absorption characteristics of Pae-LLCN in rat duodenum, jejunum, ileum and colon, and investigate the effects of different drug concentrations on intestinal absorption. Results showed that Pae-LLCN and Pae were well absorbed at different intestine segments and different concentrations. The absorption constant Ka was increased with the increasing of the drug concentration, indicating possible passive absorption. The accumulative absorption volume Q and absorption constant Ka of Pae-LLCN were higher than those of Pae at each intestinal segment(P<0.05). The results revealed that Pae-LLCN and Pae could be well absorbed in whole intestinal segments and its mechanism may be passive absorption. LLCN can effectively improve the intestinal absorption of Pae.