References of "Dewé, Walthère"
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See detailValidation des procédures analytiques quantitatives :harmonisation des démarches - Partie III. Exemples d’application
Hubert, Philippe ULg; Nguyen-Huu, Jean-Jacques; Boulanger, Bruno ULg et al

in STP PHARMA PRATIQUES (2006), 16(2), 87-121

A harmonized approach for the validation of analytical methods based on accuracy profile was introduced by a SFSTP commission on the validation of analytical procedure. This third and last document aims ... [more ▼]

A harmonized approach for the validation of analytical methods based on accuracy profile was introduced by a SFSTP commission on the validation of analytical procedure. This third and last document aims at illustrating this methodology and the statistics used. Therefore the validation of real case methods are proposed such as methods for the quality control of drugs, for the quantitation of impurities in drug substances, for bioanalysis or for the determination of nutriments. Furthermore, different types of analytical methods are used in order to demonstrate the applicability of the proposed approach to a wide range of methods such as liquid chromatography (LC-UV, LC-MS), spectrophotometry or ELISA. [less ▲]

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See detailValidation des procédures analytiques quantitatives :Partie II - Statistiques
Hubert, Philippe ULg; Nguyen-Huu, Jean-Jacques; Boulanger, Bruno ULg et al

in STP PHARMA PRATIQUES (2006), 16(1), 28-58

In a first document, a SFSTP Commission on the Validation of Analytical Procedure has introduced a harmonized approach for the validation of analytical procedures. In order to complete this guide, the ... [more ▼]

In a first document, a SFSTP Commission on the Validation of Analytical Procedure has introduced a harmonized approach for the validation of analytical procedures. In order to complete this guide, the statistical methodology allowing to correctly conclude about the validity of a procedure is proposed in this second part of the guide. Indeed all the steps to obtain the decision tool namely the accuracy profile are described. This tool, based on the concept of total error (bias + standard deviation), allows to easily take the right decision and simultaneously minimizing the risk of the future use of the analytical procedure. [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 detailApproches par l'erreur totale en transfert analytique
Dewé, Walthère ULg; Boulanger, Bruno ULg; Govaerts, B. et al

Conference (2006)

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See detailAccuracy and precision : total error vs 4-6-30
Boulanger, Bruno ULg; Dewé, Walthère ULg; Hubert, Philippe ULg et al

Conference (2006)

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See detailLes laboratoires accrédités saisis par l'incertitude
Feinberg, Max; Laurentie, M.; Hubert, Philippe ULg et al

Conference (2006)

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See detailSynchronization of validation and estimation strategies of doubt associated as part of the accreditation in trial laboratories
Hubert, Philippe ULg; Rozet, Eric ULg; Boulanger, Bruno ULg et al

in Acta Clinica Belgica (2006), 61(Suppl. 1), 54-56

In order to achieve the harmonization of validation strategies, the interpretation of several validation criteria is proposed. Furthermore, a simple and visual decision tool to assess the validity of an ... [more ▼]

In order to achieve the harmonization of validation strategies, the interpretation of several validation criteria is proposed. Furthermore, a simple and visual decision tool to assess the validity of an analytical procedure is described: the accuracy profile based on the estimation of the total error of the measurements. This profile build with beta-expectation tolerance intervals can also compute with efficiency the uncertainty related to the results of a laboratory, which is an essential parameter for the accreditation of laboratories under ISO 17025. [less ▲]

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See detailHarmonisation des strategies de validation et estimation de l'incertitude associee dans le cadre de l'accreditation des laboratoires d'essais
Hubert, Philippe ULg; Rozet, Eric ULg; Boulanger, Bruno ULg et al

in Acta Clinica Belgica. Supplementum (2006), S1(1), 53-55

In order to achieve the harmonization of validation strategies, the interpretation of several validation criteria is proposed. Furthermore, a simple and visual decision tool to assess the validity of an ... [more ▼]

In order to achieve the harmonization of validation strategies, the interpretation of several validation criteria is proposed. Furthermore, a simple and visual decision tool to assess the validity of an analytical procedure is described: the accuracy profile based on the estimation of the total error of the measurements. This profile build with beta-expectation tolerance intervals can also compute with efficiency the uncertainty related to the results of a laboratory, which is an essential parameter for the accreditation of laboratories under ISO 17025. [less ▲]

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See detailWhat happens with adverse events during 6 months of treatment with selective serotonin reuptake inhibitors?
Demyttenaere, K.; Albert, Adelin ULg; Mesters, P. et al

in Journal of Clinical Psychiatry (2005), 66(7), 859-863

Objective: Although adverse events are a key factor in compliance, their evolution during treatment with antidepressants is poorly documented. Therefore, the time course of adverse events during 6 months ... [more ▼]

Objective: Although adverse events are a key factor in compliance, their evolution during treatment with antidepressants is poorly documented. Therefore, the time course of adverse events during 6 months of antidepressant treatment was investigated. Method: 85 psychiatric outpatients with a DSM-IV diagnosis of major depressive disorder (with the exclusion of other DSM-IV Axis I disorders) were enrolled between September 2002 and March 2003 in a multicenter, randomized, double-blind trial with selective serotonin reuptake inhibitors (fluoxetine [N = 421 and paroxetine [N = 43]). At each visit, the presence and severity of treatment-emergent adverse events were assessed systematically using the UKU Side Effect Rating Scale (UKU). General linear mixed modeling was used to investigate the predictors of the time course of adverse events. Results: Overall, the number of at least moderately severe adverse events decreased with time. More severely depressed patients reported overall more (at least moderately severe) adverse events than less severely depressed patients (p =.0002), but the decrease in reported adverse events was comparable over time. Men (N = 30) and women (N = 55) reported initially the same number of at least moderately severe adverse events, but the habituation was more rapid in men (p <.0001). Completers (N = 58) and dropouts (N = 27) did not differ initially, but completers' habituation was more rapid (p =.014). The habituation of adverse events was also more rapid in recurrent than in first-episode patients but only in men (p =.0025). Conclusion: The time course of adverse events varies with the severity of depression, sex, completer or dropout status, and recurrent versus first-episode depression. [less ▲]

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See detailInfluence of the nature of the electrolyte on the chiral separation of basic compounds in nonaqueous capillary electrophoresis using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin
Servais, Anne-Catherine ULg; Fillet, Marianne ULg; Chiap, Patrice ULg et al

in Journal of Chromatography. A (2005), 1068(1), 143-150

The influence on the enantiomeric resolution of the nature of the cationic BGE component (sodium, ammonium or potassium) and that of the anionic component (chloride, formate, methanesulfonate or ... [more ▼]

The influence on the enantiomeric resolution of the nature of the cationic BGE component (sodium, ammonium or potassium) and that of the anionic component (chloride, formate, methanesulfonate or camphorsulfonate) as well as the concentration of heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-beta-CD), the selected chiral selector, was studied in nonaqueous capillary electrophoresis (NACE). For this purpose, two D-optimal designs with 33 and 26 experimental points were applied. Three beta-blockers (atenolol, celiprolol and propranolol) and three local anesthetics (bupivacaine, mepivacaine and prilocaine) were selected as basic model compounds. Both cationic and anionic BGE components were found to have a deep impact on the enantiomeric resolution of the investigated analytes but it is the cationic component that has shown the strongest influence. Indeed, in some cases, the change of the latter led to a complete loss of enantioresolution. Based on the observed results, two NACE systems were recommended, namely ammonium formate and potassium camphorsulfonate in a methanolic solution containing HDMS-beta-CD and acidified with formic acid, in order to separate efficiently the enantiomers of basic drugs. (c) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailDevelopment of response models for optimising HPLC methods
Dewé, Walthère ULg; Marini Djang'Eing'A, Roland ULg; Chiap, Patrice ULg et al

in Chemometrics and Intelligent Laboratory Systems (2004), 74(2), 263-268

For optimizing a liquid chromatographic method, direct modeling some responses like minimum resolution is sometimes difficult to perform. By modeling the retention time at apex and the times associated to ... [more ▼]

For optimizing a liquid chromatographic method, direct modeling some responses like minimum resolution is sometimes difficult to perform. By modeling the retention time at apex and the times associated to 13.4% of the peak height, it is possible to obtain estimations of these responses using an adequate cascade of equations, these equations being the definitions of these responses. As a multi-criteria decision has to be taken in most of these optimizations, a Derringer's function can be defined for each response of interest and a overall desirability, on which the final is taken, can be derived. In addition, the chromatogram in any experimental point can be predicted. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailHarmonization of strategies for the validation of quantitative analytical procedures - A SFSTP proposal - part I
Hubert, Philippe ULg; Nguyen-Huu, J.-J.; Boulanger, Bruno ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2004), 36(3), 579-586

This paper is the first part of a summary report of a new commission of the Societe Francaise des Sciences et Techniques Pharmaceutiques (SFSTP). The main objective of this commission was the ... [more ▼]

This paper is the first part of a summary report of a new commission of the Societe Francaise des Sciences et Techniques Pharmaceutiques (SFSTP). The main objective of this commission was the harmonization of approaches for the validation of quantitative analytical procedures. Indeed, the principle of the validation of theses procedures is today widely spread in all the domains of activities where measurements are made. Nevertheless. this simple question of acceptability or not of an analytical procedure for a given application, remains incompletely determined in several cases despite the various regulations relating to the good practices (GLP, GMP,...) and other documents of normative character (ISO, ICH. FDA,...). There are many official documents describing the criteria of validation to be tested, but they do not propose any experimental protocol and limit themselves most often to the general concepts. For those reasons, two previous SFSTP commissions elaborated validation guides to concretely help the industrial scientists in charge of drug development to apply those regulatory recommendations. If these two first guides widely contributed to the use and progress of analytical validations, they present, nevertheless, weaknesses regarding the conclusions of the performed statistical tests and the decisions to be made with respect to the acceptance limits defined by the use of an analytical procedure. The present paper proposes to review even the bases of the analytical validation for developing harmonized approach, by distinguishing notably the diagnosis rules and the decision rules. This latter rule is based on the use of the accuracy profile, uses the notion of total error and allows to simplify the approach of the validation of an analytical procedure while checking the associated risk to its usage. Thanks to this novel validation approach, it is possible to unambiguously demonstrate the fitness for purpose of a new method as stated in all regulatory documents. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailNew advances in method validation and measurement uncertainty aimed at improving the quality of chemical data
Feinberg, M.; Boulanger, Bruno ULg; Dewé, Walthère ULg et al

in Analytical and Bioanalytical Chemistry (2004), 380(3), 502-514

The implementation of quality systems in analytical laboratories has now, in general, been achieved. While this requirement significantly modified the way that the laboratories were run, it has also ... [more ▼]

The implementation of quality systems in analytical laboratories has now, in general, been achieved. While this requirement significantly modified the way that the laboratories were run, it has also improved the quality of the results. The key idea is to use analytical procedures which produce results that fulfil the users' needs and actually help when making decisions. This paper presents the implications of quality systems on the conception and development of an analytical procedure. It introduces the concept of the life-cycle of a method as a model that can be used to organize the selection, development, validation and routine application of a method. It underlines the importance of method validation, and presents a recent approach based on the accuracy profile to illustrate how validation must be fully integrated into the basic design of the method. Thanks to the beta-expectation tolerance interval introduced by Mee (Technometrics (1984) 26(3):251-253), it is possible to unambiguously demonstrate the fitness for purpose of a new method. Remembering that it is also a requirement for accredited laboratories to express the measurement uncertainty, the authors show that uncertainty can be easily related to the trueness and precision of the data collected when building the method accuracy profile. [less ▲]

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See detailDevelopment of an antidepressant compliance questionnaire
Demyttenaere, K.; Bruffaerts, R.; Albert, Adelin ULg et al

in Acta Psychiatrica Scandinavica (2004), 110(3), 201-207

Objective: The development of the Antidepressant Compliance Questionnaire (ADCQ), assessing patients' attitudes and beliefs on depression and antidepressants. Method: A 51-item questionnaire was applied ... [more ▼]

Objective: The development of the Antidepressant Compliance Questionnaire (ADCQ), assessing patients' attitudes and beliefs on depression and antidepressants. Method: A 51-item questionnaire was applied to 85 psychiatric out-patients with a DSM-IV diagnosis of major depressive disorder (MDD). This data set was used to assess psychometric properties of the ADCQ. The questionnaire was also applied to 272 primary care out-patients with MDD. Results: A principal component analysis revealed four dimensions with good internal consistency and acceptable test-retest reliability: 'perceived doctor-patient relationship', 'preserved autonomy', 'positive beliefs on antidepressants' and 'partner agreement', resulting in a final questionnaire comprising 33-items. Responses were independent from depression severity and patient age. The response patterns of both psychiatric and primary care patients are provided and illustrate the many erroneous beliefs on antidepressants. Conclusion: The ADCQ has good psychometric properties; further investigation should investigate whether this questionnaire is predictive of patient compliance. [less ▲]

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See detailEnantiomeric separation of basic compounds usin heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin in combination with potassium camphorsulfonate in nonaqueous capillary electrophoresis: Optimization by means of an experimental design
Servais, Anne-Catherine ULg; Fillet, Marianne ULg; Chiap, Patrice ULg et al

in Electrophoresis (2004), 25(16), 2701-2710

The enantiomeric separation of a series of basic pharmaceuticals (beta-blockers, local anesthetics, sympathomimetics) has been investigated in nonaqueous capillary electrophoresis (NACE) systems using ... [more ▼]

The enantiomeric separation of a series of basic pharmaceuticals (beta-blockers, local anesthetics, sympathomimetics) has been investigated in nonaqueous capillary electrophoresis (NACE) systems using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-P-CD) in combination with potassium camphorsulfonate (camphorSO(3)(-)). For this purpose, a face-centered central composite design with 11 experimental points was applied. The effect of the concentrations of HDMS-beta-CD and camphorSO(3)(-) on enantioresolution was statistically evaluated and depended largely on the considered analyte. The presence of camphorSO(3)(-) was found to be particularly useful for the enantioseparation of compounds with high affinity for the anionic CD. CamphorSO(3)(-) seems to act as a competitor, reducing the affinity for the CD, probably by ion-pair formation with these analytes. For compounds with lower affinity for HDMS-beta-CD, the combination of camphorSO(3)(-) and the CD appeared to have a favorable effect on enantioresolution only if the optimal CD concentration could be reached. On the other hand, for compounds characterized by a very low affinity for the anionic CD, the association of camphorSO(3)(-) and HDMS-beta-CD is always unfavorable. Finally, experimental conditions were selected by means of the multivariate approach in order to obtain the highest resolution (R-s) value for each studied compound. [less ▲]

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