[Preparation of silymarin-loaded amphiphilic chitosan micelle and its in situ absorption in rat intestine].

To improve the oral bioavailability of silymarin, the silymarin-loaded amphiphilic chitosan micelles (SM-OGC) were prepared. The absorption of SM-OGC in rat intestine was investigated. SM-OGC was prepared by dialysis method. The size and zeta potential of SM-OGC were investigated. Compared to silymarin suspension, the absorption of SM-OGC was investigated using in situ single pass perfusion model. The diameters and zeta potential SM-OGC were (162.4 +/- 3.0) nm and (+32.6 +/- 0.98) mV, respectively. The encapsulation efficiency was (39.17 +/- 0.98)% and the drug loading of SM-OGC was (28.15 +/- 0.43)%. The absorption of SM-OGC at different segments of intestine was significantly higher than that of silymarin suspension (P < 0.05). The apparent absorption rate (K(a)) and effective permeation coefficient (P(eff)) at the duodenum were the largest. K(a) and P(eff) had no significant difference between jejunum, ileum and colon. OGC micelles might significantly promote the absorption of silymarin in the intestine tract.