State of knowledge of Cameroonian drug prescribers on pharmacovigilance

Introduction: the present study conducted in Cameroon from June 2013 to February 2014 aimed to estimating the level of pharmacovigilance knowledge and practice of health professionals in Cameroon.Methods: we conducted a descriptive cross-sectional survey on 149 health professionals in Cameroon from June to September 2013. Data were analyzed using software IBM SPSS 20.0. We calculated proportions and oddratio, and confident interval of their values, keeping a threshold of p of 0.05 to determine the level of significance.Results: ninety percent (90%) of declaration of side effects were made to the medical representatives and 4% to the National Pharmacovigilance Centre. Fifty four percent (54%) of physicians were not aware of the  existence of a National Pharmacovigilance system. Ten (10%) of  prescribers had never heard of pharmacovigilance, however respondents answered unanimously that they need training on pharmacovigilance. A wrong definition was given by most of the nurses and dentists (61,1% and 58,3% respectively) as compared to physicians and pharmacists  (respectively 15.2% and 26,5%). Given the results of this study, the  establishment of a National Pharmacovigilance system based on a solid legal foundation is necessary in Cameroon. This implementation must go through the involvement of all stakeholders and their awareness raising on the importance of this activity and its positive impact on the health of populations.Conclusion: pharmacovigilance is a public health problem in Cameroon, with due to lack of good knowledge and practice of prescribers, precisely physicians, pharmacists, nurses, and dentists who are not always aware of an existing pharmacovigilance system in Cameroon

Acute toxicity and antioxydant property of Striga hermonthica (Del.) Benth (Scrophulariaceae)

Plants containing flavonoids have been reported to possess strong antioxidant properties. The aqueous acetone extract of Striga hermonthica was further separated into aqueous and ethyl acetate fractions and assayed for their in vitro antioxidant properties using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Thecrude extract exhibits a weak antioxidant activity (IC50 of 95.27±2.30 ìg/ml) and an insignificant acute toxicity on mice (LD50: 1753±44 mg/kg). Luteolin was isolated and identified by mean of its spectral data as the main DPPH radical scavenger of the ethyl acetate fraction, exhibiting an IC50 value of 6.80±1.46 ìg/ml. These results suggest an antioxidant potential for S. hermonthica

Self-assembled biotransesterified cyclodextrins as potential Artemisinin nanocarriers. II: In vitro behavior toward the immune system and in vivo biodistribution assessment of unloaded nanoparticles.

In a previous study, we reported on the formulation of Artemisinin-loaded surface-decorated nanoparticles (nanospheres and nanoreservoirs) by co-nanoprecipitation of PEG derivatives (PEG1500 and PEG4000-stearate, polysorbate 80) and biosynthesized γ-CD fatty esters. In the present study, the co-nanoprecipitation was extended to the use of a PEGylated phospholipid, namely DMPE-PEG2000. As our goal was to prepare long-circulating nanocarriers for further systemic delivery of Artemisinin (ART), here, we have investigated, on the one hand, the in vitro behavior of these surface-modified γ-CD-C10 particles toward the immune system (complement activation and macrophage uptake assays) and, on the other hand, their biodistribution features in mice. These experiments showed that the in vitro plasma protein adsorption and phagocytosis by macrophage cells triggered by γ-CD-C10 nanoparticles were significantly reduced when their surface was decorated with amphiphilic PEGylated molecules, in particular PEG1500-stearate, DMPE-mPEG2000 or polysorbate 80. The prolonged blood circulation time assessed by fluorescence imaging was demonstrated for unloaded γ-CD-C10-based nanospheres and nanoreservoir particles containing DMPE-PEG2000 and polysorbate80, respectively. These nanoparticles also proved to be non-hemolytic at the concentration range used in vivo. Within the limits of the conducted experiments, the co-nanoprecipitation technique may be considered as an alternative for surface modification of amphiphilic CD-based drug delivery systems and may be applied to the systemic delivery of ART

Enhanced degradation of fluorene in soil slurry by Absidia cylindrospora and maltosyl-cyclodextrin

International audienceThis study investigates the fungal biodegradation of fluorene, a polycyclic aromatic hydrocarbon, in liquid medium and soil slurry. Fungal strains and cyclodextrins were used in order to degrade fluorene and optimize fluorene bioavailability and degradation in soil slurries. After a procedure of selection in solid and liquid media, maltosyl-cyclodextrin, a branched cyclodextrin was chosen. 47 fungal strains isolated from a contaminated site were tested for biodegradation. Results showed the greater efficiency of "adapted" fungi isolated from contaminated soil vs reference strains belonging to the collection of the laboratory. These assays allowed us to select the most efficient strain, Absidia cylindrospora, which was used in a bioaugmentation process. Bioaugmentation tests were performed in an artificially contaminated non-sterile soil. In the presence of A. cylindrospora, more than 90% of the fluorene was degraded within 288 h, while 576 h were necessary in the absence of fungal bioremediation. It also appeared that biodegradation was enhanced by amendment with previously selected maltosyl-cyclodextrin. The results of this study indicate that A. cylindrospora and maltosyl-cyclodextrin could be used successfully in fluorene bioremediation systems. (C) 2004 Elsevier Ltd. All rights reserved

Long-term shelf stability of original amphiphilic β-cyclodextrin nanosphere suspensions monitored by dynamic light scattering and cryo-transmission electron microscopy

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Size control of amphiphilic cyclodextrin nanoparticles using mixture design methodology

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Miscellaneous nanoaggregates made of β-CD esters synthesised by an enzymatic pathway

International audienceVarious β-cyclodextrin (β-CD) fatty esters with different chain lengths (C4–C14) were synthesised by transesterification of β-cyclodextrin by vinyl fatty ester using thermolysin in DMSO. For each cyclodextrin derivatives, two batches of synthesis were realized. The ability of these derivatives to form nano-organized systems was investigated through the solvent displacement technique. During the formulation step, the effects of the initial concentration of β-CD fatty esters in the organic phase and that of the final volume of the aqueous non-solvent phase were studied. Except for the β-CD C4 ester, the transesterified β-CD derivatives led to measurable nanoparticles. Cryo-electron microscopy images showed a significant morphological variability. Spherical, rod-like or more irregularly-shaped nano-objects were observed with either matricial or lamellar structures. A statistical analysis by a two-way ANOVA was computed for each class of β-cyclodextrin esters in order to determine the effects of batch and formulation on the final size of nanoparticles

Influence of chemical structure of amphiphilic β-cyclodextrins on their ability to form stable nanoparticles

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Progress in developing amphiphilic cyclodextrin-based nanodevices for drug delivery

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Influence of chemical structure of amphiphilic β-cyclodextrins on their ability to form stable nanoparticles

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