D. Satonin, J. D. McCulloch, F. Kuo
Jun 1, 2007
Citations
2
Influential Citations
34
Citations
Journal
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
Abstract
A sensitive bioanalytical method for the measurement of two major circulating metabolites of duloxetine [4-hydroxy duloxetine glucuronide (LY550408) and 5-hydroxy-6-methoxy duloxetine sulfate (LY581920)] in plasma is reported. This method produced acceptable precision and accuracy over the validation range of 1-1000 ng/mL. Several issues had to be addressed in order to develop an LC/MS/MS assay for these metabolites. First, 4-hydroxy duloxetine glucuronide required chromatographic resolution from the 5-, and 6-hydroxy duloxetine glucuronide isomers. Second, the glucuronide conjugate is readily ionized under positive ESI conditions, while the sulfate conjugate required negative ESI conditions to obtain adequate sensitivity. Finally, the chromatographic conditions needed to separate the glucuronide isomers were not suitable for the analysis of the sulfate conjugate. The present method addressed these challenges, and was successfully applied to multiple human pharmacokinetic studies in which subjects received oral doses of duloxetine hydrochloride.