Objective To prepare paclitaxel-natural borneol complex,and to explore the prescription and preparation process of paclitaxel-natural borneol complex drug-loaded submicroemulsion,and its in vitro anti-tumor effect.Methods The Paclitaxel-natural borneol complex was prepared by grinding method and identified by Fourier Transform infrared spectroscopy(FT-IR)and differential scanning calorimetry(DSC).The compound drug-loaded submicroemulsion was prepared using a two-step high-pressure emulsification method.The single-factor investigation and the orthogonal experimental design were applied to optimize the formulation and preparation process.MTT assay,cell cloning assay,and cell scratch assay were used to evaluate the effect of this preparation on HCT-116 cells.Results The infrared spectral absorption peaks of taxol-natural borneol complex at 3 312.76 cm-1 and 3 513.92 cm-1 disappeared,and DSC analysis showed that a new absorption peak of taxol-natural borneol complex appeared at 154.56 ℃,indicating that taxol be coupled with natural borneol to form a new complex.The optimal prescription was 0.44％active pharmaceutical ingredient[paclitaxel-natural borneol(1∶3)],10％medium chain triglyceride,3％emulsifier[egg yolk lecithin-Poloxam 188(1∶2)],2％glycerol,0.3％oleate.The optimal process was emulsification at 80 ℃,60 MPa high pressure homogenization 10 times.The half inhibitory concentration(IC50)was 0.75 μg·mL-1 by MTT asssy in cell.In the cell cloning assay,the scratch healing area of blank control group,paclitaxel raw material and paclitaxel/natural borneol submicroemulsion were(36.44±3.35)％,(13.59±9.28)％,(8.30±4.09)％,respectively.The results were statistically significant(P＜0.05).In the plate cloning experiment,the cell cloning rates of blank control group,paclitaxel bulk drug group and submicroemulsion group were(37.92±0.729)％,(9.16±1.335)％and(3.36±1.065)％,respectively,the differents were statistically significant(P＜0.05).Conclusion This submicroemulsion has reasonable prescription,feasible process and good stability.Cell experiments showed that the submicronemulision effectively inhibits the proliferation and migration of HCT-116 cells,suggesting its potential as a promising antitumor agent.