Abstract: AimTo investigate the tissue distribution and pharmacokinetics of oridonin-solid lipid nanoparticles in animals. MethodsHPLC method was established to determine the concentration of oridonin in serum of rabbits and in different tissues of mice. The results after tail iv administration of oridonin and oridonin solid lipid nanoparticles were compared. ResultsThe relative tissue content of oridonin of solid lipid nanopaticles in the liver, spleen, lung, heart and kidney were 4.25%, 3.44%, 1.19%, 0.52% and 0.60%, respectively. The concentration-time curves of oridonin and oridonin solid lipid nanoparticles were both fitted to the three-compartment model. T_1/2π=0.087 h, T_1/2α=1.65 h, T_1/2β=32.36 h, V_C=0.66 mL·kg^-1. ConclusionSolid lipid nanoparticles could increase the hepatic and lienic targeting efficiency of oridonin in mice and improve its bioavailability. Solid lipid nanoparticles were helpful for oridonin to reach a long circulation time and were hopeful to be its novel drug carrier.