A new method for the determination of omeprazole in human plasma was developed. Omeprazole was extracted from plasma with toluene-isoamylalcohol (95:5, v/v), the organic phase was evaporated, dissolved in the mobile phase and injected into a reversed-phase C18 column. Flunitrazepam was used as an internal standard. The mobile phase consisted of 47% methanol and 53% of 0.1 M dipotassium hydrogenphosphate, pH 7.8. The spectrophotometric detection was performed at 302 nm. Limit of quantitation was 9.7 ng/ml and the calibration curve was linear up to 1240 ng/ml.

• MeSH
• flunitrazepam MeSH
• indikátory a reagencie MeSH
• lidé MeSH
• omeprazol krev   MeSH
• pentanoly MeSH
• reprodukovatelnost výsledků MeSH
• rozpouštědla MeSH
• senzitivita a specificita MeSH
• stabilita léku MeSH
• toluen MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• flunitrazepam MeSH
• indikátory a reagencie MeSH
• isopentyl alcohol MeSH Prohlížeč
• omeprazol MeSH
• pentanoly MeSH
• rozpouštědla MeSH
• toluen MeSH

A rapid, sensitive and reliable method was developed to quantitate omeprazole in human plasma using liquid chromatography-tandem mass spectrometry. The assay is based on protein precipitation with acetonitrile and reversed-phase liquid chromatography performed on an octadecylsilica column (55 mm x 2mm, 3 microm particles), the mobile phase consisted of methanol-10 mM ammonium acetate (60:40, v/v). Omeprazole and flunitrazepam, the internal standard, elute at 0.80+/-0.10 min with a total run time 1.35 min. Quantification was through positive ion mode and selected reaction monitoring mode at m/z 346.1-->197.9 for omeprazole and m/z 314.0-->268.0 for flunitrazepam, respectively. The lower limit of quantitation was 1.2 ng/ml using 0.25 ml of plasma and linearity was observed from 1.2 to 1200 ng/ml. Within-day and between-day precision expressed by relative standard deviation was less than 5% and inaccuracy did not exceed 12%. The assay was applied to the analysis of samples from a pharmacokinetic study.

• MeSH
• chemická precipitace MeSH
• hmotnostní spektrometrie metody   MeSH
• inhibitory enzymů krev   farmakokinetika   MeSH
• krevní proteiny metabolismus   MeSH
• lidé MeSH
• omeprazol krev   farmakokinetika   MeSH
• protivředové látky krev   farmakokinetika   MeSH
• referenční standardy MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• validační studie MeSH
• Názvy látek
• inhibitory enzymů MeSH
• krevní proteiny MeSH
• omeprazol MeSH
• protivředové látky MeSH