Kim John, Ji HyeYoung, Kim Sook Jin, Lee Hye Won, Lee Seung-Seok, Kim Dong Sung, Yoo Moohi, Kim Won Bae, Lee Hye Suk
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
J Pharm Biomed Anal. 2003 Jun 1;32(2):317-22. doi: 10.1016/s0731-7085(03)00088-8.
A liquid chromatography-tandem mass spectrometric method for the simultaneous determination of sildenafil and its active N-demethylated metabolite, UK-103,320 in human plasma was developed. Sildenafil, UK-103,320 and the internal standard (DA-8159) were extracted from human plasma with dichloromethane at basic pH. A reverse-phase LC separation was performed on Luna phenylhexyl column with the mixture of acetonitrile-ammonium formate (10 mM, pH 6.0) (60:40, v/v) as mobile phase. The detection of analytes was performed using an electrospray ionization tandem mass spectrometry in the multiple reaction-monitoring mode. The lower limits of quantification for sildenafil and UK-103,320 were 2.0 ng/ml. The method showed a satisfactory sensitivity, precision, accuracy, recovery and selectivity.
