Determination of related substances in guaifenesin by HPLC
Objective To establish an HPLC method for the determination of related substances in guaifenesin active pharmaceutical ingredient(API).Methods The chromatographic column was Agilent ZORBAX SB C18(250 mm×4.6 mm,5 μm),and the mobile phase was water-acetonitrile(gradient elution).The flow rate was 1.0 mL·min-1,the detection wavelength was 273 nm,the column temperature was 30℃,and the injection volume was 10 μL.Results The peaks of guaifenesin and its impurities were well separated.The linear relationships between the mass concentrations and peak areas of impurities A,B,C,and D were good(r≥0.999 7),and the average recoveries(n=9)were 98.29%,101.35%,101.81%and 101.05%,and the RSDs were 1.02%,0.65%,2.83%and 0.90%,respectively.Conclusion The method is specific and accurate,and could be used for the determination of related substances in guaifenesin API,providing technical support for the improvement of the quality of guaifenesin API in China.