7 results on '"Arien, T."'
Search Results
2. Comparison between different nanocarriers : nanosuspension, polymeric micelles and nanoparticles
- Author
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UCL - SSS/LDRI - Louvain Drug Research Institute, Danhier, Fabienne, Ucakar, Bernard, Vanderhaegen, M., Brewster, M.E., Arien, T., Préat, Véronique, 26th Annual Meeting of the G.T.R.V., UCL - SSS/LDRI - Louvain Drug Research Institute, Danhier, Fabienne, Ucakar, Bernard, Vanderhaegen, M., Brewster, M.E., Arien, T., Préat, Véronique, and 26th Annual Meeting of the G.T.R.V.
- Published
- 2011
3. VERITAS deep observations of the dwarf spheroidal galaxy Segue 1.
- Author
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Aliu, E., Archambault, S., Arien, T., Aune, T., Beilicke, M., Benbow, W., Bouvier, A., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Collins-Hughes, E., Connolly, M. P., Cui, W., Decerprit, G., and Dickherber, R.
- Subjects
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ASTRONOMICAL observations , *ELLIPTICAL galaxies , *DWARF galaxies , *CHERENKOV radiation , *DARK matter , *PARTICLES (Nuclear physics) , *NUCLEAR cross sections - Abstract
The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report on the results of nearly 48 hours of good quality selected data, taken between January 2010 and May 2011. No significant y-ray emission is detected at the nominal position of Segue 1, and upper limits on the integrated flux are derived. According to recent studies, Segue 1 is the most dark matter-dominated dwarf spheroidal galaxy currently known. We derive stringent bounds on various annihilating and decaying dark matter particle models. The upper limits on the velocity-weighted annihilation cross-section are {&tou;v)95% CL ≤ 10-23 cm3 s_1, improving our limits from previous observations of dwarf spheroidal galaxies by at least a factor of 2 for dark matter particle masses mx S 300 GeV. The lower limits on the decay lifetime are at the level of T95%CI- > 1024 s. Finally, we address the interpretation of the cosmic ray lepton anomalies measured by ATIC and PAMELA in terms of dark matter annihilation, and show that the VERITAS observations of Segue 1 disfavor such a scenario. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
4. A toolbox for mimicking gastrointestinal conditions in children: Design and evaluation of biorelevant dissolution media for mimicking paediatric gastric- and small intestinal conditions.
- Author
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Freerks L, Arien T, Mackie C, Inghelbrecht S, and Klein S
- Subjects
- Adult, Child, Humans, Child, Preschool, Administration, Oral, Solubility, Fasting, Stomach, Intestine, Small
- Abstract
The goal of the present work was to develop an in vitro toolbox to evaluate the oral administration of dosage forms to children of different age groups and under different administration conditions (fasted/fed). Based on current data on the gastrointestinal physiology of children, a set of new biorelevant media was designed to mimic the composition and physicochemical properties of resting gastric and resting small intestinal fluid in children of different age groups. In addition, guidelines were developed on how to generate fasted and fed state gastric and small intestinal fluids by combining these media with age-specific drinking volumes or portions of already established simulated paediatric breakfast meals, respectively. These fluids can simulate the conditions in the paediatric stomach and small intestine after administration of a dosage form in the fasting state or after a breakfast. The in vitro toolbox was evaluated using the example of pre-school children with a total of five paediatric medicines. Results from the corresponding set of in vitro studies highlight the importance of addressing patient-specific characteristics rather than downscaling existing adult in vitro models., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
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5. A Toolbox for Mimicking Gastrointestinal Conditions in Children: Simulated Paediatric Breakfast Media (SPBM) for Addressing the Variability of Gastric Contents After Typical Paediatric Breakfasts.
- Author
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Freerks L, Zielke C, Tarnow MJ, Arien T, Mackie C, Inghelbrecht S, and Klein S
- Subjects
- Adult, Child, Drug Liberation, Humans, Solubility, Stomach, Breakfast, Food-Drug Interactions
- Abstract
Since co-administration of dosage forms with food can impact drug exposure, food effect studies became an integral part of oral drug product development. Studies are usually performed in healthy adults and the dosage form is co-administered with a high-fat high-calorie standard breakfast meal to mimic worst-case dosing conditions. A corresponding study design for children is lacking but would be essential for a proper risk-assessment in this vulnerable patient group. To protect healthy children from unnecessary in vivo studies, it would be even more desirable to predict food effects based on other than in vivo studies in the target age group. In the present study, typical children's breakfasts in different parts of the world were identified, prepared and physicochemical properties were assessed. Subsequently, Simulated Paediatric Breakfast Media (SPBM) resembling breakfast composition and properties were designed and applied in in vitro dissolution experiments mimicking the initial composition of the postprandial stomach after breakfast ingestion. Study results indicate the impact of different simulated gastric conditions on drug release. SPBM enabled to better estimate the variability of in vivo drug release in fed dosing conditions and their use will aid in better assessing food effects in children in different parts of the world., Competing Interests: Declaration of Competing Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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6. Characterisation of fasted state gastric and intestinal fluids collected from children.
- Author
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Pawar G, Papadatou-Soulou E, Mason J, Muhammed R, Watson A, Cotter C, Abdallah M, Harrad S, Mackie C, Arien T, Inghelbrecht S, and Batchelor H
- Subjects
- Administration, Oral, Adolescent, Age Factors, Child, Child, Preschool, Drug Liberation physiology, Endoscopy, Gastrointestinal, Female, Gastrointestinal Absorption, Humans, Hydrogen-Ion Concentration, Infant, Infant, Low Birth Weight metabolism, Infant, Newborn, Infant, Premature metabolism, Male, Osmolar Concentration, Solubility, Fasting metabolism, Gastric Mucosa metabolism, Gastrointestinal Contents chemistry, Intestinal Mucosa metabolism
- Abstract
Fundamental knowledge about the composition of intestinal fluids in paediatric populations is currently unavailable. This study aimed to characterise gastric and intestinal fluid from paediatric populations. Gastric and intestinal fluid samples were obtained during routine clinical endoscopy from paediatric patients at a large teaching hospital. These fluids were characterised to measure the pH; buffer capacity; osmolality; bile acid concentration and composition. A total of 55 children were recruited to the study aged from 11 months to 15 years of age where 53 gastric fluid samples and 40 intestinal fluid samples were obtained. pH values recorded ranged from pH 0.57 to 11.05 (median: 2.50) in gastric fluids and from 0.89 to 8.97 (median: 3.27) in intestinal fluids. The buffer capacity did not change significantly between gastric and intestinal fluids with median values of 12 mM/L/ΔpH for both fluids. Gastric fluid osmolality values ranged from 1 to 615 mOsm/kg, while intestinal fluid values ranged from 35 to 631 mOsm/kg. Gastric fluid bile acid concentrations ranged from 0.002 to 2.3 mM with a median value of 0.017 mM whilst intestinal fluid bile acid concentrations ranged from 0.0008 to 3.3 mM with a median value of 0.178 mM. Glycocholate; taurocholic acid; glycochenodeoxycholate and taurochenodeoxycholate were the most commonly identified bile acids within paediatric intestinal fluids. All compositional components were associated with large inter-individual variability. Further work is required to develop simulated paediatric media and to explore the impact of these media on drug solubility and dissolution., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
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7. Nanosuspension for the delivery of a poorly soluble anti-cancer kinase inhibitor.
- Author
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Danhier F, Ucakar B, Vanderhaegen ML, Brewster ME, Arien T, and Préat V
- Subjects
- Administration, Oral, Animals, Antineoplastic Agents chemistry, Area Under Curve, Drug Screening Assays, Antitumor, Humans, Hydrogen-Ion Concentration, Maximum Tolerated Dose, Mice, Mice, Nude, Micelles, Nanoparticles chemistry, Neoplasm Transplantation, Neoplasms drug therapy, Polymers chemistry, Solubility, Suspensions, Antineoplastic Agents administration & dosage, Drug Delivery Systems, Macrocyclic Compounds administration & dosage, Protein Kinase Inhibitors administration & dosage, beta-Cyclodextrins chemistry
- Abstract
We hypothesized that nanosuspensions could be promising for the delivery of the poorly water soluble anti-cancer multi-targeted kinase inhibitor, MTKi-327. Hence, the aims of this work were (i) to evaluate the MTKi-327 nanosuspension for parenteral and oral administrations and (ii) to compare this nanosuspension with other nanocarriers in terms of anti-cancer efficacy and pharmacokinetics. Therefore, four formulations of MTKi-327 were studied: (i) PEGylated PLGA-based nanoparticles, (ii) self-assembling PEG₇₅₀-p-(CL-co-TMC) polymeric micelles, (iii) nanosuspensions of MTKi-327; and (iv) Captisol solution (pH=3.5). All the nano-formulations presented a size below 200 nm. Injections of the highest possible dose of the three nano-formulations did not induce any side effects in mice. In contrast, the maximum tolerated dose of the control Captisol solution was 20-fold lower than its highest possible dose. The highest regrowth delay of A-431-tumor-bearing nude mice was obtained with MTKi-327 nanosuspension, administered intravenously, at a dose of 650 mg/kg. After intravenous and oral administration, the AUC₀₋∞ of MTKi-327 nanosuspension was 2.4-fold greater than that of the Captisol solution. Nanosuspension may be considered as an effective anti-cancer MTKi-327 delivery method due to (i) the higher MTKi-327 maximum tolerated dose, (ii) the possible intravenous injection of MTKi-327, (iii) its ability to enhance the administered dose and (iv) its higher efficacy., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
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