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See detailModèles statistiques Bayésiens et méthodologies pour calculer le Design Space (OPTIMAL-DS)
Marini Djang'Eing'A, Roland ULg; Lebrun, Pierre ULg; Hubert, Philippe ULg

Report (2011)

La compréhension des procédés technologiques et industriels dans les secteurs (bio)pharmaceutiques, biotechnologiques, agroalimentaires et environnementaux doit permettre de se conformer aux lignes de ... [more ▼]

La compréhension des procédés technologiques et industriels dans les secteurs (bio)pharmaceutiques, biotechnologiques, agroalimentaires et environnementaux doit permettre de se conformer aux lignes de conduites initiées par la FDA ou d'autres organismes de contrôles. Notamment, le document ICH Q8 introduit les notions de "Process Analytical Technology", de "Quality by Design" et de "Design Space", ayant attraits à la qualité des procédés industriels, des procédés d'analyse ainsi qu'à la qualité des produits finis. Cependant, si les lignes de conduites pour ces exigences sont expliquées, aucune méthodologie pour les atteindre n'est donnée. Or, un nombre considérable de nouvelles entités chimiques sont synthétisées par les laboratoires pharmaceutiques, biotechnologiques ou agroalimentaires. Les producteurs de matières premières et/ou d’excipients (secteur chimique) ont également besoin de disposer rapidement de méthodes analytiques de contrôle qui leur permettront de s’assurer de la qualité de leurs produits. On comprend aisément la nécessité pour ces secteurs de disposer rapidement de résultats fiables puisque les activités de recherches mais aussi des investissements, souvent importants, sont orientés ou stoppés sur base de données chiffrées, produits par les méthodes analytiques. La production de résultats fiables et la démonstration de cette fiabilité sont donc économiquement fondamentales. Ce projet vise la mise au point de stratégies et de modèles génériques de développement automatisé de nouvelles méthodes analytiques séparatives, en se basant sur la modélisation des temps de rétention, la planification expérimentale, et le concept de Design Space. L’objectif connexe est d’appliquer cette méthodologie à l’optimisation de n’importe quel procédé. Le fait de pouvoir disposer d’une méthodologie de mise au point automatique de méthodes analytiques ou de tous procédés analytiques aura un impact significatif. Cette nouvelle technologie permettra de réduire de façon drastique le temps d’optimisation des méthodes et procédés, permettant une production plus efficiente de produits (pharmaceutique, cosmétique, agro-alimentaire ou biotechnologique) répondant aux spécifications du client. [less ▲]

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See detailContrôle qualité
Marini Djang'Eing'A, Roland ULg; Ziemons, Eric ULg; Hubert, Philippe ULg

Article for general public (2011)

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See detailLe fléau des faux médicaments
Marini Djang'Eing'A, Roland ULg; Ziemons, Eric ULg; Hubert, Philippe ULg

E-print/Working paper (2011)

The traffic in counterfeit medicines is booming. It misleads, and it kills. A University of Liège team is making Rwandan and Congolese health care workers aware of the problem, whilst informing and ... [more ▼]

The traffic in counterfeit medicines is booming. It misleads, and it kills. A University of Liège team is making Rwandan and Congolese health care workers aware of the problem, whilst informing and training them, so that they may detect and monitor these products, thanks to made to measure appropriate technical systems. [less ▲]

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See detailTotal Error and Uncertainty: Friends or Foes?
Rozet, Eric ULg; Dewe, Walthere; Rudaz, Serge et al

in Trends in Analytical Chemistry (2011), 30(5), 797-806

The guidelines ISO 17025 and ISO 15189 aim at improving the quality assurance scheme of laboratories. Reliable analytical results are of core importance due to the critical decisions that are taken with ... [more ▼]

The guidelines ISO 17025 and ISO 15189 aim at improving the quality assurance scheme of laboratories. Reliable analytical results are of core importance due to the critical decisions that are taken with them. Therefore among other topics, these documents require that analytical methods be validated and that laboratories should be able to provide measurement uncertainty of their measured routine results. To evaluate analytical methods fitness of purpose, total error has been and is more and more applied to assess reliability of results generated by analytical methods. However, the ISO requirement to estimate measurement uncertainty seems in opposition with the total error concept, leading to delays in their implementation by laboratories and increased confusion for the analysts. Thus, this article aims at clarifying the divergences between total error and measurement uncertainty, but also to discuss their main similarities and give some emphasise to their implementations. [less ▲]

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See detailModels to estimate overall analytical measurements uncertainty: assumptions, comparisons and applications
Rozet, Eric ULg; Rudaz, S.; Marini Djang'Eing'A, Roland ULg et al

in Analytica Chimica Acta (2011), 702

Evaluation of analytical results reliability is of core importance as crucial decisions are taken with them. From the various methodologies to evaluate the fitness of purpose of analytical methods ... [more ▼]

Evaluation of analytical results reliability is of core importance as crucial decisions are taken with them. From the various methodologies to evaluate the fitness of purpose of analytical methods, overall measurement uncertainty estimation is more and more applied. Overall measurement uncertainty allows to combine simultaneously the remaining systematic influences to the random sources of uncertainty and allows assessing the reliability of results generated by analytical methods. However there are various interpretations on how to estimate overall measurement uncertainty, and thus various models for estimating it. Each model together with its assumptions has great impacts on the risks to abusively declare that analytical methods are suitable for their intended purpose. This review paper aims at i) summarizing the various models used to estimate overall measurement uncertainty, ii) provide their pros and cons, iii) review the main areas of application and iv) as a conclusion provide some recommendations when evaluating overall measurement uncertainty. [less ▲]

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See detailInnovative high-performance liquid chromatography method development for the screening of 19 antimalarial drugs based on a generic approach, using design of experiments, independent component analysis and design space
Debrus, Benjamin ULg; Lebrun, Pierre ULg; Mbinze Kindenge, Jérémie et al

in Journal of Chromatography. A (2011), 1218

An innovative methodology based on design of experiments (DoE), independent component analysis (ICA) and design space (DS) was developed in previous works and was tested out with a mixture of 19 ... [more ▼]

An innovative methodology based on design of experiments (DoE), independent component analysis (ICA) and design space (DS) was developed in previous works and was tested out with a mixture of 19 antimalarial drugs. This global LC method development methodology (i.e. DoE–ICA–DS) was used to optimize the separation of 19 antimalarial drugs to obtain a screening method. DoE–ICA–DS methodology is fully compliant with the current trend of quality by design. DoE was used to define the set of experiments to model the retention times at the beginning, the apex and the end of each peak. Furthermore, ICA was used to numerically separate coeluting peaks and estimate their unbiased retention times. Gradient time, temperature and pH were selected as the factors of a full factorial design. These retention times were modelled by stepwise multiple linear regressions. A recently introduced critical quality attribute, namely the separation criterion (S), was also used to assess the quality of separations rather than using the resolution. Furthermore, the resulting mathematical models were also studied from a chromatographic point of view to understand and investigate the chromatographic behaviour of each compound. Good adequacies were found between the mathematical models and the expected chromatographic behaviours predicted by chromatographic theory. Finally, focusing at quality risk management, the DS was computed as the multidimensional subspace where the probability for the separation criterion to lie in acceptance limits was higher than a defined quality level. The DS was computed propagating the prediction error from the modelled responses to the quality criterion using Monte Carlo simulations. DoE–ICA–DS allowed encountering optimal operating conditions to obtain a robust screening method for the 19 considered antimalarial drugs in the framework of the fight against counterfeit medicines. Moreover and only on the basis of the same data set, a dedicated method for the determination of three antimalarial compounds in a pharmaceutical formulation was optimized to demonstrate both the efficiency and flexibility of the methodology proposed in the present study. [less ▲]

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See detailAdvances in validation, risk and uncertainty assessment of bioanalytical methods
Rozet, Eric ULg; Marini Djang'Eing'A, Roland ULg; Ziemons, Eric ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2011), 55

Bioanalytical method validation is a mandatory step to evaluate the ability of developed methods to provide accurate results for their routine application in order to trust the critical decisions that ... [more ▼]

Bioanalytical method validation is a mandatory step to evaluate the ability of developed methods to provide accurate results for their routine application in order to trust the critical decisions that will be made with them. Even if several guidelines exist to help perform bioanalytical method validations, there is still the need to clarify the meaning and interpretation of bioanalytical method validation criteria and methodology. Yet, different interpretations can be made of the validation guidelines as well as for the definitions of the validation criteria. This will lead to diverse experimental designs implemented to try fulfilling these criteria. Finally, different decision methodologies can also be interpreted from these guidelines. Therefore, the risk that a validated bioanalytical method may be unfit for its future purpose will depend on analysts personal interpretation of these guidelines. The objective of this review is thus to discuss and highlight several essential aspects of methods validation, not only restricted to chromatographic ones but also to ligand binding assays owing to their increasing role in biopharmaceutical industries. The points that will be reviewed are the common validation criteria, which are selectivity, standard curve, trueness, precision, accuracy, limits of quantification and range, dilutional integrity and analyte stability. Definitions, methodology, experimental design and decision criteria are reviewed. Two other points closely connected to method validation are also examined: incurred sample reproducibility testing and measurement uncertainty as they are highly linked to bioanalytical results reliability. Their additional implementation is foreseen to strongly reduce the risk of having validated a bioanalytical method unfit for its purpose. [less ▲]

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See detailReliable low cost capillary electrophoresis device for drug quality control and counterfeit medicines
Marini Djang'Eing'A, Roland ULg; Rozet, Eric ULg; Montes De Lourdes Aja, Maria et al

in Journal of Pharmaceutical & Biomedical Analysis (2010), 53(5), 1278-1287

The proportion of counterfeit medicines is dramatically increasing these last few years. According to numerous official sources, in some pharmaceutical wholesalers in African countries, the proportion has ... [more ▼]

The proportion of counterfeit medicines is dramatically increasing these last few years. According to numerous official sources, in some pharmaceutical wholesalers in African countries, the proportion has reached 80%. Unfortunately, this situation is far to be improved due to lack of suitable analytical equipment allowing rapid actions of the Regulatory Agencies based on scientific consideration, at affordable cost and all over the drug supply chain. For that purpose, a network group considered that mater by building a low-cost original capillary electrophoresis (CE) equipment equipped with a new deep UV detector based on LED technology. The generic conditions for analysis were investigated: capillary zone electrophoresis (CZE) performed at acidic pH for basic drug molecules (i.e., quinine, highly used as the last antimalarial rampart), basic pH for compounds such as furosemide (a common diuretic drug) and at neutral pH for a well known antibiotic combination, trimethoprim/sulfamethoxazol. To evaluate the ability of the CE equipment for quantification, a full validation and a method comparison study were carried out for the CZE method dedicated to quinine determination. The validation involved the use of accuracy profile and total error concept to monitor the adequacy of the results obtained by the new prototype. The method comparison was based on the Bland and Altman approach by comparing results obtained by the low-cost CE and a conventional set-up. Subsequent validation studies were realized with neutral and acidic drug molecules, each focusing on a single concentration level calibration curve in order to maintain as low as possible the expenses due to reagents and thus the cost of analysis, as important advantages of CE for drug quality control. [less ▲]

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See detailPlans expérimentaux
Boulanger, Bruno ULg; Govaerts, B.; Le Boulengé, E. et al

Learning material (2010)

Vidéos du cours intitulé "Plans expérimentaux"

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See detailTransfer of a conventional LC method for the screening of conterfeit antimalarial medicines to UHPLC
Nistor, Iolanda ULg; Lecomte, Frédéric ULg; Mbinze Kindenge, Jérémie et al

Poster (2010, September)

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See detailA DESIGN SPACE APPROACH TO DEVELOP A GENERIC CE METHOD FOR THE SEPARATION OF 19 ANTIMALARIAL DRUGS
Lamalle, Caroline ULg; Marini Djang'Eing'A, Roland ULg; Debrus, Benjamin ULg et al

Poster (2010, September)

This project consists in analysing different molecules used against malaria by capillary electrophoresis (CE).

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See detailAnalytical tools to fight against counterfeit medicines
Marini Djang'Eing'A, Roland ULg; Mbinze Kindenge, J.; Montes, M. L. A. et al

in Chimica Oggi = Chemistry Today (2010), 28(5), 10-14

Counterfeiting has been dramatically increasing this last decade throughout the world and particularly in developing countries, with many consequences such as adverse impacts on public health, economics ... [more ▼]

Counterfeiting has been dramatically increasing this last decade throughout the world and particularly in developing countries, with many consequences such as adverse impacts on public health, economics and negative reputation for the pharmaceutical industry. Recognizing the magnitude of the issue, health authorities at national, regional and international levels are trying to fight against this scourge using various strategies including the setting-up of effective quality control that need to be reinforced through generic, fast and specific detection methods. To illustrate this topic, we will present several analytical tools, including liquid chromatography, low cost capillary electrophoresis and near infrared spectroscopy, developed and applied to the detection and quantification of counterfeit drugs. [less ▲]

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See detailTOLERANCE INTERVALS AS CONTROL CHART: COMPARISON TO CLASSIC SHEWHART X̅-R CONTROL CHART
Marini Djang'Eing'A, Roland ULg; Lambert, Véronique; Denooz, Raphael ULg et al

Poster (2010, September)

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See detailTotal error as natural decision criteria for analytical methods validation and transfer
Rozet, Eric ULg; Boulanger, Bruno ULg; Dewe et al

Conference (2010, September)

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See detailContribution to fight against counterfeit medecines applying several analytical tools
Marini Djang'Eing'A, Roland ULg; Mbinze Kindenge, Jérémie; Montes, M. L. A. et al

Poster (2010, September)

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See detailOut Of Specification ou Non-Conformité
Marini Djang'Eing'A, Roland ULg; Ziemons, Eric ULg; Hubert, Philippe ULg

Learning material (2010)

Detailed reference viewed: 76 (13 ULg)