Physico-Chemical and Mineralogical Characterizations of Tchiky Clays (Thies, Senegal) for Pharmaceutical Uses

Our study focused on the valuation of Tchiky clays. This work aims to evaluate its properties to explore possible uses in pharmacy. Physico-chemical and mineralogical characterizations were carried out, as well as pharmacopoeial tests and an evaluation of the antioxidant activity. Thus, chemical analysis by X-ray fluorescence spectrometry gave silicon (55.65%), iron (15.73%), aluminum (13.53%), potassium (6.05%), titanium (3.98%), magnesium (2.10%), and calcium (0.82%). X-ray diffraction showed the presence of kaolinite, quartz and illite. This study also revealed that the sample studied was essentially a plastic clay of hard consistency, with average flowability. The evaluation of the antioxidant activity gave a percentage inhibition of 62.97% for a concentration of 7.5 g/l with an IC50 of 5.5 g/l. These results should allow use as an excipient in pharmacy, particularly in liquid, semi-liquid and pasty formulations.

Assessment of Poultry Feed Contamination Level by Aflatoxin B1: Quantification by Two Chromatographic Analysis Methods

Aflatoxin B1 is a mycotoxin that can contaminate a wide feedstuffs variety. Ingestion of contaminated feed by poultry can lead to impaired health and zootechnical performances but also a human diet safety problem related to residues presence in animal origin products. Aflatoxin B1 contamination of poultry feed samples marketed in Dakar city and in peri-urban areas (Gorom, Sangalkam) was studied. A total of 15 samples were collected from Dakar city markets as well as from poultry farms in Gorom and Sangalkam areas. Aflatoxin B1 quantification was performed by high performance liquid chromatography and thin-layer chromatography. HPLC results showed that all samples were contaminated with levels ranging from 0.15 to 22 ppb, 0.099 to 2.05 ppb and 0.099 to 4.95 ppb respectively for Gorom, Sangalkam and Dakar. Only the finishing feed from Gorom had an aflatoxin B1 level above the maximum limit set by regulations. TLC is a suitable method for aflatoxins detection. However, it was associated with overestimation for aflatoxin B1 quantification. Results suggest that poultry feed represents a real source of human diet contamination. In addition, HPLC remains the most reliable quantification technique for quality control.

Validation of a Capillary Electrophoresis Method for Analyzing Chlorphenamine Maleate-Based Drugs Using the Accuracy Profile Approach

This study aimed at validating an analytical method, using the accuracy profile approach, for the assay of chlorphenamine maleate by capillary electrophoresis. The validation was done using concentrations ranging between 75% and 125% of the target concentration of 600 mg/ml. Validation standards were prepared separately in triplicate for each series. Studied validation criteria were selectivity, linearity, trueness, precision (repeatability and intermediate precision), accuracy and limits of detection and quantification. The method was selective, with recoveries ranging between 99.55% and 99.84%. The relative standard deviations of repeatability and intermediate precision were <5%. The accuracy profile confirmed the performance of the assay method between 75% and 100% of the target concentration of 600 mg/ml. The detection and quantification limits were 5 mg/l and 15 mg/l respectively. This ecological and economical method was applied to identify and quantify chlorphenamine maleate in 3 samples of chlorphenamine maleate-based drugs provided by the Senegalese National Medicines Control Laboratory. All analyzed samples were in accordance with official standards.

Evaluation of Mineral Elements Content of Senegal Fruits

This study determined mineral value and antioxidant activity of Senegal fruits for contributing to improving healthy diet and preventing some chronic diseases. Mineral element contents of Dialium guineense, Landolphia heudelotti, Mangifera indica, Cyperus esculentus and Saba senegalensis, which are widely available and consumed, were studied. The results by ICP-OES spectrophotometry after acid mineralization showed highest levels of (per 100 g fruits), calcium (158 mg), potassium (1018 mg), magnesium (532 mg), zinc (26 mg) with juice of Landolphia heudelotti fruit pulp. Mangifera indica pulp is richer in sodium (89 mg), phosphorus (556 mg), sulphur (384 mg) and silicon (110 mg). Dialium senegalensis pulp is richer in iron (23 mg) and manganese (19 mg). Lyophilized Cyperus esculentus rhizomes analyzed by atomic absorption spectrophotometry gave highest concentrations of (per 100 g fruits), calcium (2550 mg), potassium (11,843 mg) and magnesium (7669 mg) but sodium content (22 mg) is lower. In vitro antioxidant activity evaluation with the DPPH radical showed for 10 mg/ml concentration, highest inhibition percentage for Saba senegalensis 4.03%, followed by Landolphia heudelotti and Dialium guineense, which were significantly similar 2.29% and 2.20% respectively, Mangifera indica 1.7% and finally Cyperus esculentus 0.5%, but much lower compared to the ascorbic acid equal to 96.32% used as a reference.

Effect of Water Content and Grains Size Distribution on the Characteristic Resilient Young’s Modulus (<i>E_c</i>) Obtained Using Anisotropic Boyce Model on Gravelly Lateritic Soils from Tropical Africa (Burkina Faso and Senegal)

This research was carried out to determine the rheological parameters of lateritic soils in order to contribute to the improvement of the technical documents used for pavement design in tropical Africa. The study is based on the loading repeated of cyclic triaxial tests (LRT) performed at University Gustave Eiffel (formerly Institut Français des Sciences et Technologies des Transports de l’Aménagement et des Réseaux (IFSTTAR)) in Nantes with the application of the European standard EN 13286-7: 2004 [1]. The tests were performed at constant confinement stress and using the stepwise method to determine the resilient axial () and radial () deformation as a function of the axial and radial stresses. Four gravel lateritic soils from different sites selected in Burkina Faso and Senegal were the subject of this research for the triaxial tests. These materials have a maximum diameter of 20 mm and a percentage of fines less than 20%. The LRT tests were carried out on samples compacted at three moisture contents (wopm - 2%, wopm and wopm + 2%) and at 95% and 100% of optimal dry density (γdopm). Test results showed that the characteristic resilient Young’s modulus (Ec) of gravelly laterites soils depends on the compacted water content and the variation of the grains size distribution (sand (ø < 2 mm), motor (ø < 0.5 mm) and fines content (ø < 0.063 mm) obtained after (LRT). Materials with a high percent of fines (>20%), mortar and sand (Sindia and Lam-Lam) are more sensitive to variations in water content. The presence of water combined with the excess of fines leads to a decrease in modulus around 25% for Lam-Lam and 20.2% for Sindia. Materials containing a low percent of fines, mortar and sand (Badnogo and Dedougou) behave differently. And the resilient modulus increases about 225.67% for Badnogo and 312.24% for Dedougou with the rise of the water content for approximately unchanged the percentage of fines, mortar and sand. Granularity therefore has an indirect influence on the resilient modulus of the lateritic soils by controlling the effects of water on the entire system. Results of statistical analysis and coefficients of correlation (0.659 to 0.865) showed that the anisotropic Boyce’s model is suitable to predict the volumetric () and deviatoric strain () with stress path (Δq/Δp) of the lateritic soils. The predicted Er resilient Young’s modulus from anisotropic Boyce’s model varies according to the evolution of the bulk stress (). A correlation around 0.9 is obtained from the power law model.