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.