Abstract: AIM: To improve the treatment efficacy and reduce the side effect of camptothecin (CA), the antitumor drug was incorporated into solid lipid nanoparticles (SLN). METHODS: An innovative, injectable camptothecin preparation of solid lipid nanoparticles (CA-SLN) was prepared by hot dispersion technique. Concentrations of camptothecin in plasma and various organs were determined by reversed phase high performance liquid chromatography with fluorescence detection. RESULTS: The characteristic data showed that the mean particle size of the prepared CA-SLN was d_ln=196.8 nm, drug loading was 4.8%, entrapment efficiency was 99.5%, and the particles carried negative charge. In pH 7.4 phosphate buffer solution, the in vitro release characteristics were well in accord with Weibull distribution. Compared with camptothecin control solution, CA-SLN coated with Poloxamer 188 showed high concentration in brain, heart, liver, spleen, lung, kidney and plasma, leading to a prolonged plasma mean residence time (MRT). CONCLUSION: The results indicated that CA-SLN have a good targeting efficiency _{in vivo}, and the biodegradable CA-SLN may decrease the camptothecin side effects and improve its treatment efficacy.