Search results for "absorption."

Targeting metabolomics analysis of the sunscreen agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate in human urine by automated on-line solid-phase ext…

2011

The in vivo metabolism of the xenobiotic agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP), a UV filter commonly used in sunscreen cosmetic products, was studied by targeting metabolomics analysis in human urine. The metabolomic study involved the use of urine from male and female volunteers before and after application of an EDP-containing sunscreen cosmetic. The metabolism of EDP in urine was studied by using the triple quadrupole detector in a combination of Precursor Ion Scanning and Neutral Loss Scanning modes, with and without enzymatic hydrolysis. Detected metabolites were subsequently confirmed as glucuronide conjugates of 4-(N,N-dimethylamino)benzoic acid and 4-(N-methylamino)…

Characteristics of l-carnitine import into heart cells

2007

Abstract l -carnitine is an essential cofactor for the transport of fatty acids across the mitochondrial membranes. l -carnitine can be provided by food products or biosynthesized in the liver. After intestinal absorption or hepatic biosynthesis, l -carnitine is transferred to organs whose metabolism is dependent upon fatty acid oxidation, such as the skeletal muscle and the heart. The intracellular transport of l -carnitine into the cell requires specific transporters and today, several of these have been characterized. Most of them belong to the solute carrier family. Heart is one of the major target for carnitine transport and use, however basic properties of carnitine uptake by heart ce…

Intestinal transport of cefuroxime axetil in rats: absorption and hydrolysis processes.

2002

Studies were performed using three cefuroxime axetil solutions (11.8, 118 and 200 microM) in three selected intestinal segments and one cefuroxime axetil solution (118 microM) in colon of anaesthetized rats. First-order absorption rate pseudoconstants, k(ap) and effective permeability coefficients, P(eff), were calculated in each set. Absorption of cefuroxime axetil can apparently be described as a carrier-mediated transport, which obeys Michaelis-Menten and first order kinetics in the proximal segment of the small intestine and a passive diffusion mechanism in the mean and distal segments. The absorption kinetic parameters for cefuroxime axetil were obtained: Vm=0.613 (0.440) microM min-1;…

Controlled Iontophoretic Delivery in Vitro and in Vivo of ARN14140—A Multitarget Compound for Alzheimer’s Disease

2019

ARN14140 is a galantamine-memantine conjugate that acts upon both cholinergic and glutamatergic pathways for better management of Alzheimer's disease. Poor oral bioavailability and pharmacokinetics meant that earlier preclinical in vivo studies employed intracerebroventricular injection to administer ARN14140 directly to the brain. The aim of the present study was to evaluate the feasibility of using constant current transdermal iontophoresis for the noninvasive systemic delivery of ARN14140 and to quantify the amounts present in the blood and the brain. Preliminary experiments in vitro were performed using porcine skin and validated with human skin. Cumulative ARN14140 permeation across th…

Fruit and Vegetable Consumption is Inversely Associated with Plasma Saturated Fatty Acids at Baseline in Predimed Plus Trial

2021

I.D.-L. is supported by the [FI_B 00256] from the FI-AGAUR Research Fellowship Program, Generalitat de Catalunya and M.M.-M is supported by the FPU17/00513 grant. a.-H. is supported by the [CD17/00122] grant and S.K.N. is supported by a Canadian Institutes of Health Research (CIHR) Fellowship. We also thank all the volunteers for their participation in and the personnel for their contribution to the PREDIMED-Plus trial. This research was funded by CiCYT [AGL2016-75329-R] and CIBEROBN from the Instituto de Salud Carlos III, ISCIII from the Ministerio de Ciencia, Innovacion y Universidades, (AEI/FEDER, UE), Generalitat de Catalunya (GC) [2017SGR196]. The PREDIMED-Plus trial was supported by t…

Kinetic study of acamprosate absorption in rat small intestine.

2000

Acamprosate (calcium bis acetyl-homotaurine), a homotaurine derivative, a structural analogue of gamma-aminobutyric acid (GABA) and an upper homologue of taurine, is a relatively new drug used to prevent relapse in weaned alcoholics. When administered orally as enteric-coated tablets at relatively high doses, this drug has a bioavailability of about 11%; however, the intestinal absorption mechanism has not been studied in depth. The present study was therefore planned to characterize the intestinal transport of acamprosate in the rat and the effect of chronic alcohol treatment on this process, quantifying its kinetic parameters and investigating possible inhibitors. Using an in vitro techni…

Effect of surfactants on Albendazole absorption

1991

Pharmacokinetic models for the saturable absorption of cefuroxime axetil and saturable elimination of cefuroxime.

2004

Since oligopeptidic drugs such as beta-lactam antibiotics share the same carriers in humans and animals, the absorption and elimination kinetics of cefuroxime (C) were investigated in rats. Plasma C concentrations were measured by liquid chromatography. Pharmacokinetics and bioavailability of C in the rat were examined after intravenous (i.v.) administration at three doses (1.78, 8.9 and 17.8mg) of cefuroxime sodium and oral administration at two doses (2.02 and 8.9mg) of cefuroxime axetil (CA). Preliminary fits using data from intravenous administration of C showed that the drug disposition kinetics were clearly nonlinear, with an increase in plasma clearance as the intravenous dose increa…

Transdermal iontophoresis of dexamethasone sodium phosphate in vitro and in vivo: effect of experimental parameters and skin type on drug stability a…

2010

The aim of this study was to investigate the cathodal iontophoresis of dexamethasone sodium phosphate (DEX-P) in vitro and in vivo and to determine the feasibility of delivering therapeutic amounts of the drug for the treatment of chemotherapy-induced emesis. Stability studies, performed to investigate the susceptibility of the phosphate ester linkage to hydrolysis, confirmed that conversion of DEX-P to dexamethasone (DEX) upon exposure to samples of human, porcine and rat dermis for 7 h was limited (82.2+/-0.4%, 72.5+/-4.8% and 78.6+/-6.0% remained intact) and did not point to any major inter-species differences. Iontophoretic transport of DEX-P across dermatomed porcine skin (0.75 mm thic…

Labetalol absorption kinetics: Rat small intestine and colon studies

2006

Labetalol is a widely used drug for the management of hypertension, which is preferably administered by the oral route despite its low bioavailability. The objective of this study is to ascertain the mechanisms underlying its absorption as an approach to help in predicting the influence of dosage changes, possible drug-drug and drug-fruit juice interactions. Perfusion experiments have been performed in rats in two sites of absorption: the intestine and the colon. The nonlinearity of the process has been established by means of the assay of a wide range of concentrations (2-2000 microM). Fitting of the concentration versus time data allows the estimation of passive diffusion constant in the …