Abstract: The purpose of this study was to prepare dabigatran etexilate nanoemulsion to improve bioavailability of dabigatran etexilate, a poorly water-soluble drug. The physicochemical properties and the stability of dabigatran etexilate nanoemulsion were investigated. Equilibrium solubility of dabigatran etexilate in commonly used oil materials for nanoemulsion were determined for selection. Then, surfactant and co-surfactant were chosen based upon the plooted pseudo-ternary diagrams. The formulation and preparation process were further optimized with orthogonal design. As a result, the dabigatran etexilate nanoemulsion was formulated based on the system consisting of Oil Acid/Labrafac Lipophile WL1394/Cremophor RH40/Transcutol P/H₂O. The dabigatran etexilate nanoemulsion was found to have a mean diameter of(57. 5±0. 2)nm, Zeta potential of -(20. 9±1. 4)mV, and the drug encapsulation efficiency of(85. 2±1. 0)%. Besides, the droplet size, stability constant and drug content of the nanoemulsion was found to have no significant changes in at least 3 months under room temperature. In conclusion, the uniform and stable dabigatran etexilate nanoemulsion with a clear and translucent appearance was obtained after the optimization of formulation and preparation process. Thus nanoemulsion could be a promising way for the improvement of bioavailability of dabigatran etexilate and other poorly water-soluble drugs.