A novel ethaselen injection formulation has been developed in our laboratory. The objective of the present study was to establish and validate a high performance liquid chromatography （HPLC） method for the determination of ethaselen in its injection formulation. Analysis was performed on an ODS column with isocratic elution at 40 ℃. Mobile phase was consisted of 0.01% phosphoric acid and methanol （60：40, v/v）. The detection wavelength was set at 320 nm and the flow rate was 1.0 mL/min. The results showed that the calibration curves of ethaselen were linear in the range of 10-50 μg/mL （r2 = 0.9999）. The limit of detection for ethaselen was 100 ng/mL. The average recovery of ethaselen was 100.14%. The labeled content of ethaselen in its injection formulation was in the range of 102%-103% of the measured content. In conclusion, this method was stable and reproducible, thus providing a useful tool for the routine analysis of this novel ethaselen injection formulation.
