In vitro release behavior and in situ absorption of evodiamine loaded microemulsion / 中国药理学通报

ABSTRACT

Aim To study the characteristics of in vitro release and in situ absorption of evodiamine load-ed microemulsion (EDM).Methods EDM was pre-pared, its release in pH 1.2 HCl solution and pH 6.8 phosphate buffer solution were studied by dialysis , and the cumulative release rates were calculated .The sin-gle-pass intestinal perfusion was used to study the ab-sorption of EDM in duodenum , jejunum , ileum and co-lon, the absorption in stomach was also studied , and the absorption rate constant ( Ka ) and effective perme-ability (Pef ) of the drug were calculated.The concen-tration of ED was measured by HPLC .Results The cumulative release rate of EDM and ED in pH 1.2 HCl solution was ( 64.76 ±0.73 )％, ( 13.98 ±0.49 )％, respectively , and that of EDM was 4.63 times of ED . In pH 6.8 phosphate buffer solution the cumulative re-lease rate was ( 91.72 ± 0.51 )％, ( 18.34 ± 0.20)％, respectively, which was 5.01 times of ED. The Ka of EDM was more than 3 times of ED, and Pef was more than 2 times of ED .Conclusion Microe-mulsion can improve in vitro release and in situ absorp-tion of ED.