Objective: To investigate in vivo pharmacokinetics and tissue distribution of silybin gelatin microspheres in rats. Method: With silybin injection as reference

pharmacokinetic model and parameters were calculated by 3P97. In vivo tissue distribution and targeting of silybin gelatin microspheres in rats were evaluated by targeting efficiency. Result: Pharmacokinetic data fitted a two-compartment model

main pharmacokinetic parameters of silybin gelatin microspheres were as follows: t 1/2α=(0.572 8±0.108 6) h

t 1/2β=(20.686 6±1.058 8) h

CL=(0.003 8±0.001 4) mL·h·kg-1

AUC0→∞=(211.095 0±10.272 8) mg·h·L-1.Targeting efficiency of it in liver

spleen

heart and kidney were 2.093

1.986

0.634

0.259. Conclusion: Compared to silybin injection

silybin gelatin microspheres could improve tendency for liver and spleen

and help improving its therapeutic effect.