RESUMO
OBJECTIVE: To establish an HPLC method for the simultaneous determination of butorphanol tartrate, dextroisomer and benzethonium chloride which works as the bacteriostatic agent in butorphanol tartrate injection on a cyclodextrin chiral column. METHODS: The HPLC analysis was performed on an Astec Cyclobond II cyclodextrin chiral column (4.6 mm×250 mm, 5 μm), with mobile phase consisting of 0.05 mol·L-1 ammonium acetate solution (pH was adjusted to 4.1 by acetic acid) and acetonitrile using gradient elution at a flow rate of 1.0 mL·min-1. The detection wavelength was set at 280 nm. RESULTS: The method showed good linearity for the three components to be measured. The linear ranges were 0.04-2.0 mg·mL-1 for butorphanol tartrate (r=0.999 9), 0.01-2.0 mg·mL-1 for dextroisomer (r=1.000 0), and 0.02-1.0 mg·mL-1 for benzethonium chloride (r=0.999 9), respectively. The average recoveries were 100.2%, 100.7%, and 99.4%, respectively. CONCLUSION: The method is simple, accurate and reproducible. It can be used for the quality control of butorphanol tartrate injection.