Determination of Crude Drug 4-O-Methyl-benzenesulfonyl-2(3H)-benzoxazolone and Its Related Substances by HPLC

OBJECTIVE To establish an HPLC method for determining the content of non-steroidal anti-inflammatory compound 4-O-methyl-benzenesulfonyl-2(3H)-benzoxazolone(MBB) and its related substances. METHODS The chromato- graphic separation was performed on an Odyssil C₁₈ column (150 mm×4.6 mm, 5 μm). The mobile phase was consisted of methanol-water(65∶35) at a flow rate of 0.8 mL·min^?1. The detection wavelength was set at 273 nm and the column temperature was 25 ℃. RESULTS MBB was completely separated from impurities. The linear range was 1-150 μg·mL^?1, and the regression equation was A=3 959.8C-283 1(r=0.999 7). The average recovery was 99.2%(RSD=1.1%, n=9). The limit of detection was 1 ng. CONCLUSION The analytical method was simple, accurate and selective for the analysis of crude drug MBB and its related substances.