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See detailCombination of Partial Least Squares regression and Design of Experiments to model the retention of pharmaceuticals in Supercritical Fluid Chromatography
Andri, Bertyl ULg; Dispas, Amandine ULg; Marini Djang'Eing'A, Roland ULg et al

in Journal of Chromatography. A (2017)

This work presents a first attempt to establish a model of the retention behaviour for pharmaceutical compounds in gradient mode SFC. For this purpose, multivariate statistics were applied on the basis of ... [more ▼]

This work presents a first attempt to establish a model of the retention behaviour for pharmaceutical compounds in gradient mode SFC. For this purpose, multivariate statistics were applied on the basis of data gathered with the Design of Experiment (DoE) methodology. It permitted to build optimally the experiments needed, and served as a basis for providing relevant physicochemical interpretation of the effects observed. Data gathered over a broad experimental domain enabled the establishment of well-fit linear models of the retention of the individual compounds in presence of methanol as co-solvent. These models also allowed the appreciation of the impact of each experimental parameter and their factorial combinations. This approach was carried out with two organic modifiers (i.e. methanol and ethanol) and provided comparable results. Therefore, it demonstrates the feasibility to model retention in gradient mode SFC for individual compounds as a function of the experimental conditions. This approach also permitted to highlight the predominant effect of some parameters (e.g. gradient slope and pressure) on the retention of compounds. Because building of individual models of retention was possible, the next step considered the estab- lishment of a global model of the retention to predict the behaviour of given compounds on the basis of, on the one side, the physicochemical descriptors of the compounds (e.g. Linear Solvation Energy Relationship (LSER) descriptors) and, on the other side, of the experimental conditions. This global model was established by means of partial least squares regression for the selected compounds, in an experimental domain defined by the Design of Experiment (DoE) methodology. Assessment of the model’s predic- tive capabilities revealed satisfactory agreement between predicted and actual retention (i.e. R2 = 0.942, slope = 1.004) of the assessed compounds, which is unprecedented in the field. [less ▲]

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See detailOptimization and validation of a fast Supercritical Fluid Chromatography method for the quantitative determination of vitamin D3 and its related impurities.
Andri, Bertyl ULg; Lebrun, Pierre ULg; Dispas, Amandine ULg et al

in Journal of Chromatography. A (2017)

In the uprising context of green analytical chemistry, Supercritical Fluid Chromatography (SFC) is often suggested as an alternative to Normal Phase Liquid Chromatography. Indeed, SFC provides fast ... [more ▼]

In the uprising context of green analytical chemistry, Supercritical Fluid Chromatography (SFC) is often suggested as an alternative to Normal Phase Liquid Chromatography. Indeed, SFC provides fast, efficient and green separations. In this report, the quantitative performances of SFC were challenged on a real-life case study: the Quality Control (QC) of vitamin D3. A rapid and green SFC method was optimized thanks to the Design of Experiments–Design Space (DoE–DS) methodology. It provided robust and high quality separation of the compounds within a 2 min timeframe, using a gradient of ethanol as co-solvent of the carbon dioxide. The analytical method was fully validated according to the total error approach, demon- strating the compliance of the method to the specifications of U.S. Pharmacopeia (USP: 97.0–103.0%) and European Pharmacopeia (EP: 97.0–102.0%) for an interval of [50–150%] of the target concentration. In order to allow quantification of impurities using vitamin D3 as an external standard in SFC-UV, correction factors were determined and verified during method validation. Thus, accurate quantification of impu- rities was demonstrated at the specified levels (0.1 and 1.0% of the main compound) for a 70.0–130.0% dosing range. This work demonstrates the validity of an SFC method for the QC of vitamin D3 raw material and its application to real samples. Therefore, it supports the switch to a greener and faster separative technique as an alternative to NPLC in the pharmaceutical industry. [less ▲]

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See detailQualité des médicaments antipaludéens et caractéristiques des pharmacies des territoires périurbains de Kinshasa
Mavungu Landu, Don Jethro ULg; Liégeois, Sophie; Manzambi Kuwekita, Joseph ULg et al

Poster (2016, December 14)

Contexte: Le paludisme causé par le Plasmodium falciparum demeure un problème majeur de santé publique. Le traitement avec des antipaludiques de bonne qualité est une composante importante dans le ... [more ▼]

Contexte: Le paludisme causé par le Plasmodium falciparum demeure un problème majeur de santé publique. Le traitement avec des antipaludiques de bonne qualité est une composante importante dans le contrôle de cette maladie. Cependant en Afrique centrale, plus de 25% des médicaments serait contrefaits ou de qualité inférieure, situation qui serait encore plus dramatique dans les territoires périurbains. Méthode: Dans le contexte ci-mentionné, une étude préliminaire et prospective a été menée dans la zone de santé de Mont Ngafula 1 située dans les territoires périurbains de la Ville de Kinshasa durant la période allant du 22 février au 17 mars 2016. Treize échantillons de poudre pour suspension d’artéméther et de luméfantrine ont été collectés. L’analyse de la qualité de ces médicaments a été réalisée au moyen de méthodes séparatives génériques utilisant la technique de chromatographie liquide à haute performance couplé à un détecteur à barrettes de diodes. Une caractérisation a été également effectuée dans 127 établissements pharmaceutiques sur base des normes édictées par le Ministère de la Santé Publique congolais. Résultats: Les résultats des analyses des échantillons d’antimalariques (ou antipaludéens) montre que presque la moitié des poudres pour suspension d’artéméther et de luméfantrine ne contenait pas la concentration prévue en artéméther et/ou en luméfantrine. Par ailleurs, le résultat des observations évoque qu’aucun établissement pharmaceutique ne respecte l’ensemble des normes du Ministère de la Santé Publique. [less ▲]

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See detailL’Assurance Qualité dans un laboratoire
Marini Djang'Eing'A, Roland ULg; Widart, Joëlle ULg; Hubert, Philippe ULg

Learning material (2016)

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See detailQuality Control Laboratories involved in the WHO Prequalification
Marini Djang'Eing'A, Roland ULg

Conference (2016, October)

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See detailFingerprinting and validation of a LC-DAD method for the analysis of biflavanones in Garcinia kola-based antimalarial improved traditional medicines
Tshisekedi Tshibangu, Pascal ULg; Mutwale Kapepula, Paulin ULg; Kabongo Kapinga, Marie Josée et al

in Journal of Pharmaceutical & Biomedical Analysis (2016), 128(2016), 382-390

African populations use traditional medicines in their initial attempt to treat a range of diseases. Nevertheless, accurate knowledge of the composition of these drugs remains a challenge in terms of ... [more ▼]

African populations use traditional medicines in their initial attempt to treat a range of diseases. Nevertheless, accurate knowledge of the composition of these drugs remains a challenge in terms of ensuring the health of population and in order to advance towards improved traditional medicines (ITMs). In this paper chromatographic methods were developed for qualitative and quantitative analyses of a per os antimalarial ITM containing Garcinia kola. The identified analytical markers were used to establish TLC and HPLC fingerprints. G. kola seeds were analysed by HPLC to confirm the identity of the extract used by the Congolese manufacturer in the ITM. The main compounds (GB1, GB2, GB-1a and Kolaflavanone) were isolated by preparative TLC and identified by UPLC–MS and NMR. For the quantification of the major compound GB1, a simple and rapid experimental design was applied to develop an LC method, and then its validation was demonstrated using the total error strategy with the accuracy profile as a decision tool. The accurate results were observed within 0.14–0.45 mg/mL range of GB1 expressed as naringenin. The extracts used in several batches of the analysed oral solutions contained GB1 (expressed as naringenin) within 2.04–2.43%. Both the fingerprints and the validated LC-DAD were found suitable for the quality control of G. kolabased raw material and finished products, respectively. [less ▲]

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See detailMédicaments usage de faux
Sacre, Pierre-Yves ULg; Ziemons, Eric ULg; Hubert, Philippe ULg et al

Article for general public (2016)

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See detailOverview of the Analytical Lifecycle of Supercritical Fluid Chromatography Methods
Andri, Bertyl ULg; Dispas, Amandine ULg; Marini Djang'Eing'A, Roland ULg et al

in American Journal of Analytical Chemistry (2016), 7

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See detailAnalytical Tools and Strategic Approach to Detect Poor Quality Medicines, Identify Unknown Components, and Timely Alerts for Appropriate Measures: Case Study of Antimalarial Medicines
Habyalimana, Védaste ULg; Mbinze Kindenge, Jérémie; Kalenda Tshilombo, Nicodème ULg et al

in American Journal of Analytical Chemistry (2015), 6

Nowadays, the circulation of poor quality medicines is becoming an alarming worldwide phenomenon with serious public health and socio-economic concerns. The situation is particularly critical in ... [more ▼]

Nowadays, the circulation of poor quality medicines is becoming an alarming worldwide phenomenon with serious public health and socio-economic concerns. The situation is particularly critical in developing countries where drug quality assurance and regulatory systems for drug manufacturing, importation, distribution and sales are weak. A sustained vigilance on poor quality medicines that regroup counterfeit/falsified, substandard and degraded medicines is therefore required to ensure patient safety and genuine medicines integrity. A case situation is illustrated including a strategic approach and analytical tools that were found useful to detect poor quality medicines, identify unknown components, and timely alerts for appropriate measures against the spread of those harmful products. Several suspected medicines randomly sampled in several strategic Rwandan areas were firstly check-controlled by means of visual inspection and then applying several analytical techniques from simple to more complex ones. The following medicines were studied: quinine sulfate tablets, artemisinin-based combination tablets, and artesunate powders for injection. Taking into account the pharmaceutical forms and the chemical characteristics, the following tests were applied: uniformity of mass, friability, disintegration, fluorescence, identification and assay. They were followed by more complex analytical techniques that allowed more comprehension of abnormal findings among which the presence of a wrong active pharmaceutical ingredient in quinine sulfate tablets which is mainly discussed in this paper to illustrate a strategic approach and various analytical tools that can be used in detecting and identifying unknown component in poor quality medicines. [less ▲]

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See detailVALIDATION RELEVANCE OF ANALYTICAL METHODS IN BIOTECHNOLOGY
Marini Djang'Eing'A, Roland ULg; Hubert, Philippe ULg

Conference (2015, September 24)

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See detailDevelopment, validation and comparison of NIR and Raman methods for the identification and assay of poor-quality oral quinine drops.
Mbinze Kidenge, Jérémie; Sacre, Pierre-Yves ULg; Yemoa, Achille et al

in Journal of Pharmaceutical & Biomedical Analysis (2015), 111

Poor quality antimalarial drugs are one of the public’s major health problems in Africa. The depth of this problem may be explained in part by the lack of effective enforcement and the lack of efficient ... [more ▼]

Poor quality antimalarial drugs are one of the public’s major health problems in Africa. The depth of this problem may be explained in part by the lack of effective enforcement and the lack of efficient local drug analysis laboratories. To tackle part of this issue, two spectroscopic methods with the ability to detect and to quantify quinine dihydrochloride in children’s oral drops formulations were developed and validated. Raman and Near Infrared (NIR) spectroscopy were selected for the drug analysis due to their low cost, non-destructive and rapid characteristics. Both of the methods developed were successfully validated using the total error approach in the range of 50-150% of the target concentration (20% W/V) within the 10% acceptance limits. Samples collected on the Congolese pharmaceutical market were analyzed by both techniques to detect potentially substandard drugs. After a comparison of the analytical performance of both methods, it has been decided to implement the method based on NIR spectroscopy to perform the routine analysis of quinine oral drop samples in the Quality Control Laboratory of Drugs at the University of Kinshasa (DRC). [less ▲]

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