References of "Lecomte, Frédéric"
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See detailControlled release of drugs from multi-component biomaterials
Zalfen, Alina ULg; Nizet, D.; Jérôme, Christine ULg et al

in Acta Biomaterialia (2008), 4(6), 1788-1796

In order to control their release, drugs are encapsulated into systems which are expected to provide a certain site with a predetermined amount of drug over a well-defined period of time. Here we report ... [more ▼]

In order to control their release, drugs are encapsulated into systems which are expected to provide a certain site with a predetermined amount of drug over a well-defined period of time. Here we report on a multi-component drug delivery biomaterial that consists of a hydrogel matrix in which drug-loaded biodegradable microcarriers are dispersed, and whose potential applications could be found in the design of implantable devices with long-term activity, as required by contraceptive and hormone replacement treatments. The release profile of the drug can actually be tuned by the complex interplay of several release mechanisms, including the permeability and eventually the degradation rate of the microcarriers and the diffusion through the hydrogel. The hydrogel consisted of 2-hydroxyethyl methacrylate cross-linked by ethylene glycol dimethacrylate. The microcarriers were biodegradable poly-ε-caprolactone (PCL) microspheres in which active molecules, such as levonorgestrel (LNG), were encapsulated. The hydrogels were characterized by water swelling, thermal properties, LNG diffusion through drug-free and drug-depleted hydrogel membranes and LNG release from devices with drug dispersed in the hydrogel. The PCL microspheres were observed by scanning electron microscopy; their size distribution, LNG loading and release were also investigated. The hydrogel-microsphere assemblies were characterized in terms of the distribution of the microspheres within the hydrogel, water swelling and the release of the encapsulated molecules. The developed device, due to its composite structure, has the ability to combine several release mechanisms, leading to drug release obeying zero-order kinetics for most of the time. [less ▲]

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See detailQualification de l'appareillage
Mbinze Kindenge, Jérémie; Marini Djang'Eing'A, Roland ULg; Lecomte, Frédéric ULg et al

Learning material (2008)

Fournir des bases et une information générale sur le principe de la qualification d'un équipement analytique.

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See detailUse of supercritical fluids technology (PGSS) for the production of betametazone loaded solid lipid microparticles
Nizet, Dominique; Jaspart, Séverine ULg; Brion, Michael et al

Poster (2008)

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See detailRisk-Based Approach for the Transfer of Quantitative Methods: Bioanalytical Applications
Rozet, Eric ULg; Dewé, Walthère ULg; Morello, R. et al

in Journal of Chromatography. A (2008), 1189

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate ... [more ▼]

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate step before routine implementation of the method at the receiving site. The conventional statistical approaches generally used in this domain which analyze separately the trueness and precision characteristics of the receiver do not achieve this. Therefore, this paper aims first at demonstrating the applicability of two recent statistical approaches using total error-based criterion and taking into account the uncertainty of the true value estimate of the sending laboratory, to the transfer of bioanalytical methods. To achieve this, they were successfully applied to the transfer of two fully automated liquid chromatographic method coupled on-line to solid-phase extraction. The first one was dedicated to the determination of three catecholamines in human urine using electrochemical detection, and the second one to the quantitation of N-methyl-laudanosine in plasma using fluorescence detection. Secondly, a risk-based evaluation is made in order to understand why classical statistical approaches are not sufficient to provide the guarantees that the analytical method will give most of the time accurate results during its routine use. Finally, some recommendations for the transfer studies are proposed. [less ▲]

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See detailPerformances of a multidimensional on-line SPE-LC-ECD method for the determination of three major catecholamines in native human urine: Validation, risk and uncertainty assessments
Rozet, Eric ULg; Morello, Rosa; Lecomte, Frédéric ULg et al

in Journal of Chromatography. B : Analytical Technologies in the Biomedical & Life Sciences (2006), 844(2), 251-260

A novel, multidimensional on-line SPE-LC method with electrochemical detection is described for the fully automated and direct analysis of the catecholamines norepinephrine, epinephrine and dopamine in ... [more ▼]

A novel, multidimensional on-line SPE-LC method with electrochemical detection is described for the fully automated and direct analysis of the catecholamines norepinephrine, epinephrine and dopamine in urine. The integrated extractive clean-up of the raw biofluid is based on a SPE-column packed with restricted access material (RAM) which is modified with the affinity ligand nitrophenylboronic acid. The method was fully validated according to a recent approach based on an accuracy profile. The acceptance limits were set at +/- 15% of the nominal concentration values. The method was found accurate over a concentration range from 15 to 500 mu g/l for norepinephrine, from 5 to 500 mu g/l for epinephrine and from 50 to 500 mu g/l for dopamine. The relative risk for the use of the validated method in routine analysis was also assessed based on this validation strategy. It was found that at most 3.5% of future sample measurements will fall outside the acceptance limits. This demonstrates the high reliability of the analytical method described. Moreover, the measurements uncertainties were deduced from the validation experiments without any additional effort. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailLe transfert d'une methode de dosage automatisee de la noradrenaline dans l'urine humaine: utilisation de l'erreur totale comme critere de decision
Rozet, Eric ULg; Dewé, Walthère ULg; Chiap, Patrice ULg et al

in Acta Clinica Belgica. Supplementum (2006), (1), 57-9

Two new statistical approaches based on the total error of measurements were applied to the transfer of an automated method for the determination of noradrenalin in human urine by LC-ECD coupled on-line ... [more ▼]

Two new statistical approaches based on the total error of measurements were applied to the transfer of an automated method for the determination of noradrenalin in human urine by LC-ECD coupled on-line to SPE. They showed that the receiving laboratory was mastering the analytical procedure allowing it to use the method in routine. Furthermore the risk based approach gave guarantee that the risk to have future measurements out of specification in the receiving laboratory was smaller than 5%, therefore being a risk management tool. [less ▲]

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See detailLe transfert d’une méthode de dosage automatisée de 3 catécholamines majeures dans l’urine humaine: utilisation de l’erreur totale comme critère de décision
Rozet, Eric ULg; Dewé, W.; Chiap, Patrice ULg et al

Conference (2005)

Objectif : Un transfert analytique consiste à transférer physiquement une méthode analytique précédemment validée depuis le laboratoire émetteur vers un laboratoire receveur après avoir démontré que le ... [more ▼]

Objectif : Un transfert analytique consiste à transférer physiquement une méthode analytique précédemment validée depuis le laboratoire émetteur vers un laboratoire receveur après avoir démontré que le laboratoire receveur maîtrise la méthode. Il est donc essentiel d’avoir toutes les garanties que la méthode est en effet maîtrisée par le laboratoire receveur. Deux nouvelles approches statistiques basées sur l’utilisation de l’erreur totale comme outil de décision quant à la validité d’un transfert de méthodes analytiques ont été décrites (1). Nous nous proposons ici de montrer l’applicabilité de ces deux approches au cas du transfert d’une méthode de dosage automatique de trois catécholamines majeures dans l’urine humaine. [less ▲]

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