A bio-analytical hydrophilic interaction LC-MS/MS method for the simultaneous quantification of omeprazole and lansoprazole in human plasma in support of a pharmacokinetic omeprazole study in children

✍ Scribed by Julie De Smet; Koen Boussery; Pieter De Cock; Peter De Paepe; Jean-Paul Remon; Myriam Van Winckel; Jan Van Bocxlaer

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 206 KB
• Volume: 33
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.200900590

✦ Synopsis

Abstract

A hydrophilic interaction LC method with MS/MS was developed and validated for the simultaneous quantification of omeprazole and lansoprazole in human plasma. Chromatographic separation was achieved on a Betasil silica column using a high organic mobile phase (eluent A: ACN/formic acid 997.5:2.5 v/v; eluent B: water/formic acid 997.5:2.5 v/v) and gradient elution. The mass spectrometer was operated in the Multiple Reaction Monitoring mode. Prior to chromatography, liquid–liquid extraction with ethyl acetate was used and the organic layer was diluted with ACN, allowing direct injection on column. The method showed acceptable linearity, high precision (RSD%<10.5%), accuracy (88.9–109.3%) and selectivity in the two concentration ranges studied: 1.5–100 and 5–2000 ng/mL. The LOQ was established at 1.5 and 5 ng/mL for the two concentration ranges. Lack of variability in matrix effects was demonstrated and mean extraction recovery for omeprazole and lansoprazole was determined in the low (56.3–67.7%) and high (45.3–44.3%) concentration range, respectively. Additionally, plasma samples were found to be stable after three freeze–thaw cycles and for at least 15 h after extraction. This assay was successfully applied to a pharmacokinetic omeprazole study in children with cerebral palsy and mental retardation.