Abstract: AimTo prepare lipid microsphere of sodium norcantharidin (NCTD) and then study their characters and pharmacokinetic behavior. MethodsDynamic Light Scattering, HPLC and retrodialysis technique were used to determine the in vitro characters of the NCTD loaded lipid microsphere (LM), such as the particle size, ζ-potential, content, incorporation ratio, release profile and changes after dilute. And the plasma concentration was determined by HPLC-MS, compared with NCTD aqueous solution at the same time. ResultsEvery property showed that the LM was preferable. The average diameter was about 200 nm. The ζ-potential was -38 mV. The content was close to 100%. And the incorporation ratio exceeded 80%. After i.v. administration of single dose, the pharmacodynamic parameter of LM AUC was 111.28 μg·mL^-1·h^-1. The data of plasma concentrations showed that the NCTD LM was of two compartment. There was no obvious difference between in vivo parameters of LM and reference solution. ConclusionThe NCTD LM was eligible and the character of it in vivo was not changed.