Abstract: Common cationic nanostructure lipid carriers (cNLCs) and bovine serum albumin-coated cationic nanostructure lipid carriers (BSA-cNLCs) were prepared by solvent evaporation method.Particle size of cNLCs and BSA-cNLCs were 69.9 nm and 80 nm,with zeta potential of +12.5 mV and +5.02 mV,respectively.Both NLCs were approximately spherical in shape,and BSA layer on the surface of BSA-cNLCs was obvious.The PTX encapsulation efficiencies of both NLCs were above 97%,with drug loading efficiency of above 3.7%.After being incubated with plasma for 24 h,the particle size of cNLCs and BSA-cNLCs increased by 70% and 10%,respectively,indicating improved stability of BSA-cNLCs in comparison with cNLCs.The pharmacokinetics in rat and biodistribution in tumor-bearing mice of PTX-loaded NLCs after intravenous injection were investigated by HPLC.PTX concentration in rat blood was 0.64 μg/mL 12 h after injection of BSA-cNLCs,while no PTX could be detected in cNLCs group.In tumor-bearing mice received PTX-loaded BSA-cNLCs and cNLCs injection,c_max in tumor tissue was 8.36 μg/mL and 2.52 μg/mL,and decreased to 1.56 μg/mL and 0.57 μg/mL,respectively,12 h later.In comparison with cNLCs,the residence time in blood of BSA-cNLCs increased significantly,displaying longer circulating capability and better tumor-targeting efficiency.