Objective      To develop a high performance liquid chromatography (HPLC) method for detecting benactyzine hydrochloride and its related substances in the injection.       Methods      HPLC was performed to detect benactyzine and its related substances under the wave length of 210 nm under 30 ℃. The chromatographic conditions were as follow: the mixed solvent of acetonitrile and buffer of potassium dihydrogen phosphate (each 1 000 mL containing 6.80 g of potassium dihydrogen phosphate

0.556 g sodium heptanesulfonate) (35∶65) was used as mobile phase

flow rate was 1 mL/min

injection volume was 20 μL.       Results      The total peak areas of related substances did not exceed 1% of the main peak area of reference solution. The linear ranges of benactyzine hydrochloride were 1 to 200 μg/mL (r=0.999 5). The average recoveries of high

medium and low concentrations were 98.99%（RSD=0.67%）

99.96%（RSD=0.10%）

and 101.21%（RSD=0.11%）respectively. The RSD of intra-day (n=3) and inter-day assay (n= 5) were less than 2%. The limit of quantitation was 1.7 ng

and the limit of detection was 0.4 ng.       Conclusion      Our HPLC method is proved to be highly selective

accurate and suitable for the quality control of benactyzine hydrochloride injection.