[The absorption kinetics of oleanolic acid self-microemulsion in rat stomach and intestine].

OBJECTIVE: To study the absorption kinetics of oleanolic acid self-microemulsion in rat stomach and intestine. METHODS: The absorption kinetics were obtained by using the in situ perfusion method in rat. The absorption of drug was determinated by the decrease in stomach and intestine with the HPLC as the detection method. RESULTS: The absorption percent of oleanolic acid microemulsion for 2 hours was 10.15% in stomach; The absorption rate constants of oleanolic acid microemulsion and micelle were 0.0901/h and 0.0486/h in small intestine, respectively; The best absorption segment in intestine was duodenum, ileum, jejunum and colon by turns. CONCLUSION: The oleanolic acid self-microemulsifying system significantly enhances the absorption of oleanolic acid in the gastrointestinal tract and improves its bioavailability.