Whey proteins analysis in aqueous medium and in artificial gastric and intestinal fluids

Whey proteins isolates (WPI) were treated in aqueous medium at various pH values. Zeta potential, turbidity and particle size measurement were determined as a function of pH. FTIR analysis was performed in ATR mode (attenuated total reflectance). Digestibility was assessed by treating whey proteins with artificial gastric and intestinal fluids. Proteolytic enzymes such as pepsin from porcine stomach mucosa was added in the gastric fluid. Pancreatin and trypsin from porcine and bile salts were added in the intestinal fluid. SDS-PAGE revealed hydrolysis of á-lactalbumin and bovine serum albumin by pepsin while â-lactoglobulin was not hydrolyzed by gastric fluid. All the proteins of WPI were easily hydrolyzed in the intestinal fluid. The zeta potential of WPI went from positive values to negative values as the pH was increased. Turbidity values indicated the presence of particles in the solution which were confirmed by the measurement of particle size. FTIR analysis determined the fingerprint of WPI macromolecule

Stabilité des suspensions reconstituées de la combinaison thérapeutique antipaludique à base d’artéméther-luméfantrine avec différents types d’eaux

Les combinaisons thérapeutiques antipaludiques à base d’artéméther-luméfantrine sous forme de poudres lyophilisées, sont des préparations multidoses destinées aux enfants pour le traitement du paludisme. Dans le but d’obtenir une bonne observance thérapeutique chez les enfants, ces poudres lyophilisées à reconstituer ont été mises sur le marché. La stabilité des suspensions obtenues après reconstitution avec différents types d’eau accessible à toutes les couches sociales dans les zones endémiques de paludisme a été évaluée. Les caractères organoleptiques et le pH des suspensions ont été recherchés. Les teneurs en artéméther et en luméfantrine ont été recherchés respectivement par chromatographie liquide et par spectrométrie UV. Les produits de dégradation de l’artéméther et de la luméfantrine ont aussi été recherchés par chromatographie sur couche mince de gel de silice. Des études microbiologiques ont été réalisées pour la recherche des germes anaérobies viables totaux et la recherche d’entérobactéries. L’étude a révélé que les caractères organoleptiques et le pH de chaque suspension ont été acceptables. Les principes actifs n’ont pas été dégradés après reconstitutions des poudres lyophilisées dans tous les échantillons durant la période d’étude. Les concentrations obtenues en artéméther et en luméfantrine de tous les échantillons analysés, étaient conformes aux normes. Les échantillons n’ont pas été contaminés par des bactéries, des levures et des moisissures au cours de cette période d’étude.© 2016 International Formulae Group. All rights reserved.Mots clés: Stabilité, artéméther, luméfantrine, suspension, spectrophotométrie, chromatographieEnglish Title: Stability of reconstituted suspension of artemether-luméfantrine lyophilized powders against malaria with different types of waterEnglish AbstractThe artemether-lumefantrine antimalarial therapeutic combinations in the form of lyophilized powders are multidoses preparations intended for the treatment of children against malaria. For obtaining a good therapeutic observance on the children, the lyophilized powders to be reconstituted were launched on the  market. The stability of the suspensions obtained after reconstitution with various types of water accessible to all sectors of society in the endemic zone of malaria was evaluated. The organoleptic characteristics and pH of the suspensions were evaluated. The concentrations of artemether and lumefantrine were respectively sought by liquid chromatography and UV spectrometry. Also the degradation products of artemether and lumefantrine were searched by thin layer chromatography. Microbiological studies were realized for the search of total viable anaerobic germs and anterobacteria. The study revealed that the organoleptic characteristics and pH of every suspension were acceptable. Active substances were not degraded after reconstitutions of lyophilized powders in all the samples during the period of study. The artemether and lumefantrine concentrations obtained were in agreement with the standards. Samples were not contaminated by bacteria, yeasts and molds during this period of study.© 2016 International Formulae Group. All rights reserved.Keywords: Stability, artemether, lumefantrine, , suspension, spectrophotometry, chromatograph

Aluminum corrosion inhibition by cefixime drug: experimental and DFT studies

Corrosion inhibition of aluminum in 1 M HCl by cefixime drug has been studied at 298-318 K using mass loss, Tafel polarization (at 298 K) and quantum chemical methods based on density functional theory (DFT) calculations. The results showed that inhibition efficiency increases up to 90.41 % with increase of the inhibitor concentration from 0.02 to 2 mM, but decreases with a rise of the solution temperature. Adsorption of cefixime molecules on the corroding aluminum surface obeys Langmuir adsorption isotherm and occurs spontaneously mostly through a physisorption process. The activation energy (Ea) as well as other thermodynamic parameters of the inhibition process are calculated and discussed. Potentiodynamic polarization data revealed that cefixime acts as mixed-type inhibitor and pointed out an agreement with mass loss results. Surface analysis is performed using scanning electron microscopy (SEM) which confirmed existence of a protective film of inhibitor molecules on the aluminum surface. In addition, global and local reactivity parameters of the studied molecule are analyzed and discussed. The computed results are found in agreement with experimental data

Études de la porosité, de la surface spécifique et des fonctions de surface de charbons actifs préparés après carbonisation artisanale des coques de noix de coco

The coconut shells as residues of the Ivorian agriculture were valued in activated carbons (C3 and C4) from raw coconut shells. The physical activation in the presence of CO2 and N2 was the method used. The BET surface areas obtained were 522 m2g-1 for C3 and 581 m2g-1 for C4. The average pore size was comprised between 20 Å and 500 Å. Total acidity (2.76 meqg-1 for C3 and 4.40 meqg-1 for C4) and total basicity (1.11 meqg-1 for C3 and 1.70 meqg-1 for C4) were assessed. These activated carbons present good specific surfaces compared with literature data. Their use as adsorbents in the degradation of organic and inorganic pollutants in aqueous media should be considered.Les coques de noix de coco en tant que résidus de l’agriculture ivoirienne ont été valorisées en charbons actifs. Les charbons actifs C3 et C4 ont été activés à partir des charbons issus de coques de coco, par la méthode d’activation physique en présence de CO2 et de N2. Les surfaces spécifiques BET obtenues sont de 581 m2g-1 pour C3 et 522 m2g-1 pour C4, la taille moyenne des pores est comprise entre 20 Å et 500 Å, l’acidité totale est de 2,76 méqg-1 pour C3 et 4,40 méqg-1 pour C4, et la basicité totale de 1,11 méqg-1 pour C3 et 1,70 méqg-1 pour C4. Ces charbons actifs présentent de bonnes surfaces spécifiques comparées aux données de la littérature. Leur utilisation comme agents adsorbants dans la captation de polluants organiques et inorganiques dans les milieux aqueux est à envisager

Encapsulation in an alginate–goats’ milk–inulin matrix improves survival of probiotic Bifidobacterium in simulated gastrointestinal conditions and goats’ milk yoghurt

In this work, a new encapsulating matrix, alginate–goats’ milk–inulin, was used to encapsulate Bifidobacterium animalis subsp. lactis BB‐12. The addition of inulin resulted in capsules with a compact structure, and a higher probiotic cell count under simulated gastrointestinal conditions and in probiotic goats’ milk yoghurt during refrigerated storage. Encapsulation of the probiotic bacteria led to slower post‐acidification yoghurts. The results of this study showed that the alginate–goats’ milk–inulin matrix has potential to be used as a new encapsulation material to encapsulate probiotics for use in goats’ milk‐based probiotic fermented dairy products, avoiding the cross‐contamination caused by using capsules based on cows’ milk

CLSM method for the dynamic observation of pH change within polymer matrices for oral delivery

If acid-sensitive drugs or cells are administered orally, there is often a reduction in efficacy associated with gastric passage. Formulation into a polymer matrix is a potential method to improve their stability. The visualization of pH within these materials may help better understand the action of these polymer systems and allow comparison of different formulations. We herein describe the development of a novel confocal laser-scanning microscopy (CLSM) method for visualizing pH changes within polymer matrices and demonstrate its applicability to an enteric formulation based on chitosan-coated alginate gels. The system in question is first shown to protect an acid-sensitive bacterial strain to low pH, before being studied by our technique. Prior to this study, it has been claimed that protection by these materials is a result of buffering, but this has not been demonstrated. The visualization of pH within these matrices during exposure to a pH 2.0 simulated gastric solution showed an encroachment of acid from the periphery of the capsule, and a persistence of pHs above 2.0 within the matrix. This implies that the protective effect of the alginate-chitosan matrices is most likely due to a combination of buffering of acid as it enters the polymer matrix and the slowing of acid penetration

Physicochemical aspects of encapsulation and release of probiotics

Mon travail de thèse s'est inscrit dans une démarche de développement de méthodes d'encapsulation en vue de protéger des probiotiques contre les effets de l'acidité gastrique. Divers matériaux d'encapsulation (alginate de sodium, acide pectique, kappa-carThis thesis developed an encapsulation method to protect probiotics against gastric acidity effects. Various encapsulation materials (sodium alginate, pectic acid, kappa-carrageenan, whey proteins) were studied. The encapsulation method by extrusion/gela

Deficiency of alpha-Tocopherol in Seminal Fluid as a Probable Factor in Low Fertility in Côte d’Ivoire

To evaluate the level of alpha-Tocopherol in seminal fluid of patients with low fertility, forty subjects with low fertility (17 with asthenospermia and 32 with oligoasthenospermia) and 21 subjects with normal sperm parameters were recruited into this study for assessing their alpha-Tocopherol seminalfluid level. The mean level of alpha-Tocopherol in subjects with normal sperm profile was 0.62 ìmol/l compared to those with pathological profile such as asthenospermia (0.29 ìmol/l) and oligoasthenospermia (0.28 ìmol/l). The determination of alpha-Tocopherol in human seminal fluidprovides useful information concerning the exploration of low fertility in Cote d’Ivoire (Afr J Reprod Health 2009; 13[3]:123-125)

Probiotic Encapsulation Technology: From Microencapsulation to Release into the Gut

Probiotic encapsulation technology (PET) has the potential to protect microorgansisms and to deliver them into the gut. Because of the promising preclinical and clinical results, probiotics have been incorporated into a range of products. However, there are still many challenges to overcome with respect to the microencapsulation process and the conditions prevailing in the gut. This paper reviews the methodological approach of probiotics encapsulation including biomaterials selection, choice of appropriate technology, in vitro release studies of encapsulated probiotics, and highlights the challenges to be overcome in this area