ESTIMATION OF GUAIFENESIN IN HUMAN PLASMA BY LIQUID CHROMATOGRAPHY COUPLED WITH TANDEM MASS SPECTROSCOPY
A simple, accurate liquid chromatography with tandem mass spectrometry (LCMS/MS) method has been developed and validated for quantification of guaifenesin in human plasma. The method employed liquid-liquid extraction (LLE) technique. Glibenclamide was used as the internal standard. Samples containing guaifenesin were chromatographed on a Kromosil C18 column (5μm, 150mm x 4.6mm) at a temperature of 40°C. The isocratic mobile phase composition was a mixture of methanol/0.1% formic acid, which was pumped at a flow rate of 0.6 mL/ min with split ratio of 90:10. The retention time under these chromatographic comditions was found to be 1.05 and 1.47 minutes for guaifenasin and glibenclamide with run time 2.2 minutes. Tert butyl methyl ether was found to be good extracting and produced a satisfactory chromatogram. The mass transition ion–pair was followed as m/z 163.000 for Guaifenesin and m/z 368.968 for Glibenclamide. The developed LC/MS-MS method was found to be selective, simple, sensitive, accurate and linear for the analysis of guaifenesin in human plasma. The proposed method has been validated with linear range 23.966 to 6001.154 ng/mL for guaifenesin. The precision and accuracy values are within 5%. The overall recovery of guaifenesin was 106.12%.