This study demonstrates the development and validation of a non-aqueous capillary electrophoresis (NACE) method for enantiomeric determination of omeprazole and its metabolite 5-hydroxyomeprazole. Heptakis-(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-beta-CD) was chosen as the chiral selector in an ammonium acetate buffer acidified with formic acid in methanol. Parameters such as CD concentration, concentration of buffer electrolyte, voltage and temperature were studied in order to optimize both the enantioresolution and migration times. An experimental design was utilized for method optimization, using software Modde 5.0. Validation of the developed method showed good linearity, which was tested over a concentration range of 2.5-500 microM. The regression coefficients for S-omeprazole, S-5-hydroxyomeprazole, R-omeprazole and R-5-hydroxyomeprazole were between 0.996 and 0.997. The limits of detection for the four enantiomers were in the range from 45 to 51microM and the limits of quantification were between 149 and 170 microM with UV detection at 301nm. Using a reduced temperature of 16 degrees C gave improved resolution values, reproducibility and also decreased the occurrence of current loss within the capillary. RSD values for peak migration time were calculated to be between 0.41 and 1.48% using an inter-day study.
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http://dx.doi.org/10.1016/j.chroma.2006.07.001 | DOI Listing |
Clin Pharmacokinet
December 2024
Clinical Pharmacology, AbbVie Inc., Dept R4PK, Bldg AP31-3, 1 North Waukegan Road, North Chicago, IL, 60064-1802, USA.
Background And Objective: The objective of this study was to characterize the effects of risankizumab on the pharmacokinetics of cytochrome P450 (CYP) 1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A substrates in patients with moderately to severely active Crohn's disease (CD) or ulcerative colitis (UC) using a cocktail approach.
Methods: Patients with CD or UC (n = 20) received single doses of probe substrates for CYP1A2 (caffeine 100 mg), CYP2C9 (warfarin 10 mg), CYP2C19 (omeprazole 20 mg), CYP2D6 (metoprolol 50 mg), and CYP3A (midazolam 2 mg) before and after intravenous infusions of risankizumab 1800 mg once every 4 weeks for four doses. Serial blood samples were collected for determination of concentrations of the CYP probe drugs and metabolites with and without risankizumab.
Metabolites
September 2024
Center of Excellence in Drug Interaction Science, Certara USA, 4 Radnor Corporate Center, Suite 350, Radnor, PA 19087, USA.
Background/objectives: Index substrates are used to understand the processes involved in pharmacokinetic (PK) drug-drug interactions (DDIs). The aim of this analysis is to review metabolite measurement in clinical DDI studies, focusing on index substrates for cytochrome P450 (CYP) enzymes, including CYP1A2 (caffeine), CYP2B6 (bupropion), CYP2C8 (repaglinide), CYP2C9 ((S)-warfarin, flurbiprofen), CYP2C19 (omeprazole), CYP2D6 (desipramine, dextromethorphan, nebivolol), and CYP3A (midazolam, triazolam).
Methods: All data used in this evaluation were obtained from the Certara Drug Interaction Database.
J Vet Intern Med
November 2024
Washington State University, Pullman, Washington, USA.
Background: Some studies in humans show that the concurrent use of clopidogrel and omeprazole decreases plasma clopidogrel active metabolite (CAM) concentrations and clopidogrel antiplatelet effects. Whether this drug interaction occurs in cats is unknown.
Hypothesis: We hypothesized that administration of clopidogrel with omeprazole would decrease plasma CAM concentrations and decrease clopidogrel antiplatelet effects in healthy cats.
Curr Drug Metab
September 2024
Shanghai Bioduro Biologics Co., Ltd, China.
Background: Ferrets exhibit similar lung physiology to humans and display similar clinical signs following influenza infection, making them a valuable model for studying high susceptibility and infection patterns. However, the metabolic fate of several common human CYP450 probe substrates in ferrets is still unknown and has not been studied.
Objective: The purpose of this study was to investigate the metabolism of nine human CYP450 probe substrates in ferret hepatocytes and explore their metabolic rate differences between ferrets and other species.
Eur J Pharm Sci
November 2024
Division of Clinical Pharmacology & Toxicology, University Hospital Basel, Switzerland; Department of Biomedicine, University of Basel, Switzerland; Department of Clinical Research, University Hospital Basel, Switzerland. Electronic address:
Phenotyping serves to estimate enzyme activities in healthy persons and patients in vivo. Low doses of enzyme-specific substrates are administered, and activities estimated using metabolic ratios (MR, calculated as AUC/AUC). We administered the Basel phenotyping cocktail containing caffeine (CYP1A2 substrate), efavirenz (CYP2B6), flurbiprofen (CYP2C9), omeprazole (CYP2C19), metoprolol (CYP2D6) and midazolam (CYP3A) to 36 patients with liver cirrhosis and 12 control subjects and determined free and total plasma concentrations over 24 h.
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