Abstract: OBJECTIVE To establish a method for the determination of entrapment efficiency of bezafibrate nanostructured lipid carriers. METHODS Free bezafibrate was separated from the nanostructured lipid carriers by Sephadex gel, with HPLC on analysis for determination of entrapment efficiency of bezafibrate nanostructured lipid carriers. An Agilent ZORBAX SB-C₁₈ column(250 mm×4.6 mm, 5 μm) was used, and 0.01 mol·L^-1 phosphate buffer (pH 3.0)-methanol(30∶70) was used as the mobile phase. The flow rate was 1.0 mL·min^-1. The detection wavelength was 230 nm. The sample volume was 20 μL. RESULTS The peak of bezafibrate and impurity could be separated well. The linear range of bezafibrate was 4.44-177.6 μg·mL^-1(r=0.999 9). The recovery of bezafibrate was 99.23%(RSD=0.68%). The entrapment efficiency of 3 batches of bezafibrate nanostructured lipid carriers were all >75%. CONCLUSION The proposed method is simple, applicable and accurate for determination of entrapment efficiency of bezafibrate nanostructured lipid carriers.