Determination of pseudoephedrine hydrochloride in human plasma by HPLC

AIM To establish a HPLC method for the determination of pseudoephedrine hydrochloride in human plasma.METHODS The analytical column was packed with ZORBAX SB-C18.The mobile phase was acetonitrile- 0.15 mol·L~(-1)NaH_2PO_4(pH=3.0)-water-0.5 % SDS(33:15:42:10).The flow rate was 1.0 mL·min~(-1).The detection wavelength was 206 nm.Plasma samples were extracted with ethyl acetate and N-hexane.The organic phase was separat- ed and acidified with 0.1 mL 1.5 % HCl,and detected at 206 nm.RESULTS The liner range of pseudoephedrine hy- drochloride in human plasma was 5.0-400μg·L~(-1)(r=0.999 9).The limit of detection was 5.0μg·L~(-1).Intra-day and inter-day RSD for assaying the plasma sample containing three concentration of pseudoephedrine hydrochloride were both lower than 10%.Relative recovery rate was at 85%-115% and absolute recovery rate was more than 75%. CONCLUSION The HPLC method to determine pseudoephedrine hydrochloride in plasma is simple,high selectivity and sensitivity.