Objective: To optimize preparation process of baicalin nanocrystallines and investigate its stability. Method: Taking mean particle size and polydispersity index(PDI) as indicators

preparation process of baicalin nanosuspensions was optimized by single factor tests.Baicalin nanocrystallines was then collected by centrifugation and freeze-dried

morphology of obtained nanocrystals were analyzed

initial stability of nanosuspensions and its freeze-dried powder were also observed.Equilibrium solubility of coarse baicalin and nanocrystals was compared by shaking flask method. Result: Nanosuspensions were prepared by injecting 1 mL of baicalin solution in DMSO(50 g·L-1) into 20 mL of 0.5% lecithin solution by a high shear of 30 000 r·min-1 for 8 min under ice-water bath.These obtained nanocrystals showed an average particle size of 280.6 nm (PDI=0.047) and that of 583.6 nm (PDI=0.12) after freeze-drying

these nanocrystals were investigated as sphere-like particles;Particle size of nanosuspensions increased up to 672.0 nm after stored at room temperature for 30 d

but no significant change was found for freeze-dried powder of nanocrystals.Equilibrium solubility of nanocrystals showed as 1.64-fold of coarse baicalin. Conclusion: Precipitation method showed to be a simple and feasible approach to prepare baicalin nanosuspensions with solubility increased

but more attention should be paid to collection and drying process which affect particle size and stability of nanocrystals.