Influence of food on bioanalytical results

Abstract

Event Abstract Back to Event Influence of food on bioanalytical results Constantin Mircioiu1* and V Anuta1 1 Carol Davila University of Medicine & Pharmacy, Romania Introduction. An essential characteristic of bioanalytical determinations in bioequivalence studies is the fact plasma samples are collected in a fasting period as well as post- prandial . Following changes in the plasma composition after ingestion of food , analytical results have to be more or less affected . Methods. Ex vivo measurements concerned determination of extraction yield of active substances ketoconazole and carbamazepine from plasma in presence of surfactant tween 80 in concentrations before and after critical micellar concentration. Clinical experiment was a bioequivalence study comparing two omeprazole formulations. Omeprazole was determined by a HPLC method using lansoprazole as internal standard. Results. Dependence of recovery of ketoconazole and carbamazepine from plasma was strongly dependent on surfactant concentrations, the extraction yield becoming double at higher concentration. On other hand, dependence was not linear, at small concentrations probably “local micellar concentrations” a decrease of recovery being observed. The phenomenon appeared at all three drug concentrations: 1, 5 and 10 µg/ml. Statistical evaluation of food effect compared the found concentrations of internal standard – lansoprazole in some 1500 pre and post prandial plasma samples. As marker and metric of food effects it was defined a “Post Prandial Matrix Effect - PPME” as the ratio of area of analytic peaks of internal standard of corresponding samples. It was found that PPME is less than 1. In fact, examination of entire time domain put in evidence a continuous increase of recovery of is maybe connected with some evolution in plasma composition connected with fasting, interrupted by the changes associated with food absorption. In the neighborhood of time of food intake appears a parabolic evolution rather than a sudden decrease. Conclusion. Food effects on results of bioanalytical determination based on liquid/liquid extractions are a resultant of surfactants effects on rate and extent of transfer of analytes, but also of some physiological changes in plasma composition and properties before and after food intake. Keywords: Food, bioanalytic results, Omeprazole Conference: 8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010, Thessaloniki, Greece, 1 Oct - 5 Oct, 2010. Presentation Type: Invited speaker Topic: Food, drugs and environmental xenobiotics Citation: Mircioiu C and Anuta V (2010). Influence of food on bioanalytical results. Front. Pharmacol. Conference Abstract: 8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010. doi: 10.3389/conf.fphar.2010.60.00167 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 Mar 2011; Published Online: 04 Nov 2010. * Correspondence: Dr. Constantin Mircioiu, Carol Davila University of Medicine & Pharmacy, Bucharest, Romania, constantin.mircioiu@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Constantin Mircioiu V Anuta Google Constantin Mircioiu V Anuta Google Scholar Constantin Mircioiu V Anuta PubMed Constantin Mircioiu V Anuta Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.