Determination of Content of Dextromethorphan Hydrobromide Tablets Based on Quantitative Proton Nuclear Magnetic Resonance

OBJECTIVE to determine the content of dextromethorphan hydrobromide tablets based on quantitative proton nuclear magnetic resonance(qHNMR). METHODS Proton signal peaks at δ 7.05-7.15 ppm of dextromethorphan hydrobromide and δ 5.38 ppm of benzyl benzoate were served as quantitative peaks and internal standard peaks, respectively. The spectra of the mixture were collected at 300 K with 4.01 s acquisition time, 10 s relaxation delay and 32 scanning times. The results of qHNMR and HPLC were also been compared. RESULTS The speciality of qHNMR was very high. There was a linear relationship for dextromethorphan hydrobromide in the range of 5.88-23.08 mg·mL^-1. The recoveries were in the range of 98.4%-99.7%. The limit of quantitation was 0.45 mg·mL^-1 and the limit of detection was 0.10 mg·mL^-1. The content determination results of qHNMR were generally consistent with those of HPLC. CONCLUSION The qHNMR can be used for the quantitative determination of dextromethorphan hydrobromide tablets.