Search

Natural laterite fixed-bed columns intercalated with two types of layers (inert materials, such as fine sand and gravel, and adsorbent materials, such as activated carbon prepared from Balanites aegyptiaca (BA-AC)) were used for As(III) removal from an aqueous solution. Investigations were carried out to solve the problem of column clogging, which appears during the percolation of water through a natural laterite fixed-bed column. Experimental tests were conducted to evaluate the hydraulic conductivities of several fixed-bed column configurations and the effects of various parameters, such as the grain size, bed height, and initial As(III) concentration. The permeability data show that, among the different types of fixed-bed columns investigated, the one filled with repeating layers of laterite and activated carbon is more suitable for As(III) adsorption, in terms of performance and cost, than the others (i.e. non-intercalated laterite; non-intercalated activated carbon, repeating layers of laterite and fine sand; and repeating layers of laterite and gravel). A study was carried out to determine the most efficient column using breakthrough curves. The breakthrough increased from 15 to 85 h with an increase in the bed height from 20 to 40 cm and decreased from 247 to 32 h with an increase in the initial As(III) concentration from 0.5 to 2 mg/L. The Bohart–Adams model results show that increasing the bed height induced a decrease in the kAB and N0 values. The critical bed depths determined using the bed depth service time (BDST) model for As(III) removal were 15.23 and 7.98 cm for 1 and 20% breakthroughs, respectively. The results show that the new low-cost adsorptive porous system based on laterite layers with alternating BA-AC layers can be used for the treatment of arsenic-contaminated water., SCOPUS: ar.j, info:eu-repo/semantics/published

info:eu-repo/semantics/nonPublished

Near-infrared spectroscopy (NIRS) allows innovative applications in terms of quality control, for example, in raw materials verification, in process analytical technology (PAT), and in discrimination between genuine and falsified medicines. The development of small and cheap handheld devices is expanding in the field, while trying to keep similar performances as benchtop instruments have. Considering traceability and quality control of drug compounds, this work is intended to identify 13 different paracetamol tablets on the Belgian market by using NIRS. The performances of a Fourier-transform near-infrared spectroscopy (FT-NIR) benchtop and two handheld NIR spectrometers were investigated comparatively. All spectra were collected through the blister in the reflectance diffuse mode. NIR spectral fingerprints were pretreated and analyzed using principal component analysis (PCA) and classified with soft independent modeling of class analogy (SIMCA). The performances of the spectrometers were evaluated after standardization of the reference benchtop database to the handheld spectrometers. The instrumental response of the benchtop spectrometer was standardized towards the handheld device using the piecewise direct standardization (PDS) algorithm. These investigations permitted the advantages and limitations of NIR data standardization on predictive models to be pointed out. The SIMCA models based on the spectral data of the benchtop (B), handheld 1 (H1), and handheld 2 (H2) instruments had an accuracy of 99.2%, 97.7%, and 96.2%, respectively. The same accuracy was obtained with the models of the transferred benchtop spectra for the H1 and H2 devices. However, adding handheld spectra to the transferred benchtop spectra resulted in models with improved accuracy: from 97.7% to 98.5% for the H1 instrument and from 96.2% to 97.7% for the H2 instrument. The proposed strategy highlights the potential of using a reference database collected by NIRS for pharmaceutical analyses by, SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ed.j, info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/published

info:eu-repo/semantics/nonPublished

info:eu-repo/semantics/published

Modified-release oral drug delivery dosage forms are widely used in the pharmaceutical field to overcome all the potential issues imposed by the physiological variabilities of the gastrointestinal tract as well as to maintain drug concentrations within the therapeutic window. In the market, they are available only as solid dosage forms such as capsules or tablets. The development of a liquid oral dosage form with modified-release properties has been keenly awaited. This form could increase the compliance of patients with a swallowing impairment (i.e. paediatric, older or critically ill patients) and, consequently, the efficacy of the therapeutic treatment. In this study, a new technology has been developed that consists of multi-layered particles suspended extemporaneously in a syrup. Omeprazole and budesonide have been employed as model drugs. The coating procedure was optimized to obtain a yield of minimum 90% w/w and a median diameter below 500 µm. Once the final suspension is prepared extemporaneously, it presents sufficient stability to guarantee the administration of multiple doses filled into a syrup bottle and kept for a limited storage time at room temperature (e.g. up to 10 doses to be administered within 10 days)., Doctorat en Sciences biomédicales et pharmaceutiques (Pharmacie), info:eu-repo/semantics/nonPublished

Accumulating evidence suggests that the bactericidal activity of some antibiotics may not be directly initiated by target inhibition. The activity of isoniazid (INH), a key first-line bactericidal antituberculosis drug currently known to inhibit mycolic acid synthesis, becomes extremely poor under stress conditions, such as hypoxia and starvation. This suggests that the target inhibition may not fully explain the bactericidal activity of the drug. Here, we report that INH rapidly increased Mycobacterium bovis BCG cellular ATP levels and enhanced oxygen consumption. The INH-triggered ATP increase and bactericidal activity were strongly compromised by Q203 and bedaquiline, which inhibit mycobacterial cytochrome bc 1 and F o F 1 ATP synthase, respectively. Moreover, the antioxidant N-acetylcysteine (NAC) but not 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPOL) abrogated the INH-triggered ATP increase and killing. These results reveal a link between the energetic (ATP) perturbation and INH’s killing. Furthermore, the INH-induced energetic perturbation and killing were also abrogated by chemical inhibition of NADH dehydrogenases (NDHs) and succinate dehydrogenases (SDHs), linking INH’s bactericidal activity further to the electron transport chain (ETC) perturbation. This notion was also supported by the observation that INH dissipated mycobacterial membrane potential. Importantly, inhibition of cytochrome bd oxidase significantly reduced cell recovery during INH challenge in a culture settling model, suggesting that the respiratory reprogramming to the cytochrome bd oxidase contributes to the escape of INH killing. This study implicates mycobacterial ETC perturbation through NDHs, SDHs, cytochrome bc 1 , and F o F 1 ATP synthase in INH’s bactericidal activity and pinpoints the participation of the cytochrome bd oxidase in protection against this drug under stress conditions.