Tina Kauss

Rutoside decreases human macrophage-derived inflammatory mediators and improves clinical signs in adjuvant-induced arthritis.

BackgroundDietary flavonols may play an important role in the adjunct therapy of chronic inflammation. The availability of therapeutic formulations of pentahydroxyflavone glycoside, rutoside (RU), led us to investigate the ability of this molecule to modulate the release of various proinflammatory mediators from human activated macrophages in vitro and to ameliorate arthritic markers in a rat model.MethodsRU was added simultaneously to human macrophages during their activation. Cells were then analyzed for inflammation-related gene expression using a specific array, and cell supernatants were collected to measure inflammatory mediators. RU was also injected into adjuvant-induced arthritic rats, and disease progression and body weight were evaluated until 50 days after injection. Sera and peritoneal macrophages were also collected to quantify the RU effect on various inflammatory markers.ResultsRU inhibited inflammation-related gene expression in activated human macrophages and the release of nitric oxide, tumor necrosis factor-alpha, interleukin (IL)-1, and IL-6 from these cells. In a rat model, RU inhibited clinical signs of chronic arthritis, correlating with decreased levels of inflammatory cytokines detected in rat sera and macrophage supernatants.ConclusionThus, RU may have clinical value in reducing inflammatory manifestations in human arthritis and other inflammatory diseases.

The initial pharmaceutical development of an artesunate/amodiaquine oral formulation for the treatment of malaria: a public-private partnership

BackgroundArtemisinin-based combination therapy is currently recommended worldwide for the treatment of uncomplicated malaria. Fixed-dose combinations are preferred as they favour compliance. This paper reports on the initial phases of the pharmaceutical development of an artesunate-amodiaquine (ASAQ) bilayer co-formulation tablet, undertaken following pre-formulation studies by a network of scientists and industrials from institutions of both industrialized and low income countries.MethodsPharmaceutical development was performed by a research laboratory at the University Bordeaux Segalen, School of Pharmacy, for feasibility and early stability studies of various drug formulations, further transferred to a company specialized in pharmaceutical development, and then provided to another company for clinical batch manufacturing. The work was conducted by a regional public-private not-for-profit network (TropiVal) within a larger Public Private partnership (the FACT project), set up by WHO/TDR, Médecins Sans Frontières and the Drugs for Neglected Disease initiative (DNDi).ResultsThe main pharmaceutical goal was to combine in a solid oral form two incompatible active principles while preventing artesunate degradation under tropical conditions. Several options were attempted and failed to provide satisfactory stability results: incorporating artesunate in the external phase of the tablets, adding a pH regulator, alcoholic wet granulation, dry granulation, addition of an hydrophobic agent, tablet manufacturing in controlled conditions. However, long-term stability could be achieved, in experimental batches under GMP conditions, by physical separation of artesunate and amodiaquine in a bilayer co-formulation tablet in alu-alu blisters. Conduction of the workplan was monitored by DNDi.ConclusionsCollaborations between research and industrial groups greatly accelerated the process of development of the bi-layered ASAQ tablet. Lack of public funding was the main obstacle hampering the development process, and no intellectual property right was claimed. This approach resulted in a rapid technology transfer to the drug company Sanofi-Aventis, finalizing the process of development, registration and WHO pre-qualification of the fixed-dose co-formulation together with DNDi. The bi-layered tablet is made available under the names of Coarsucam® and Artesunate amodiaquine Winthrop®, Sanofi-Aventis. The issue related to the difficulty of public institutions to valorise their participation in such initiative by lack of priority and funding of applied research is discussed.

Solid Lipid Nanoparticles for Image-Guided Therapy of Atherosclerosis

Although the application of nanotechnologies to atherosclerosis remains a young field, novel strategies are needed to address this public health issue. In this context, the magnetic resonance imaging (MRI) approach has been gradually investigated in order to enable image-guided treatments. In this contribution, we report a new approach based on nucleoside-lipids allowing the synthesis of solid lipid nanoparticles (SLN) loaded with iron oxide particles and therapeutic agents. The insertion of nucleoside-lipids allows the formation of stable SLNs loaded with prostacycline (PGI2) able to inhibit platelet aggregation. The new SLNs feature better relaxivity properties in comparison to the clinically used contrast agent Feridex, indicating that SLNs are suitable for image-guided therapy.

CD23 mediates antimycobacterial activity of human macrophages.

ABSTRACT Engagement of surface receptors contributes to the antimicrobial activity of human immune cells. We show here that infection of human monocyte-derived macrophages (MDM) with live Mycobacterium avium induced the expression of CD23 on their membrane. Subsequent cross-linking of surface CD23 by appropriate ligands induced a dose-dependent antibacterial activity of MDM and the elimination of most infected cells. The stimulation of inducible nitric oxide synthase-dependent generation of NO from MDM after CD23 activation played a major role during their anti-M. avium activity. CD23 activation also induced tumor necrosis factor alpha (TNF-α) production from MDM. Mycobacteria reduction was partially inhibited by the addition of neutralizing anti-TNF-α antibody to cell cultures without affecting NO levels, which suggested the role of this cytokine for optimal antimicrobial activity. Finally, interleukin-10, a Th2 cytokine known to downregulate CD23 pathway, is shown to decrease NO generation and mycobacteria elimination by macrophages. Therefore, (i) infection with M. avium promotes functional surface CD23 expression on human macrophages and (ii) subsequent signaling of this molecule contributes to the antimicrobial activity of these cells through an NO- and TNF-α-dependent pathway. This study reveals a new human immune response mechanism to counter mycobacterial infection involving CD23 and its related ligands.

Pharmaceutical development and optimization of azithromycin suppository for paediatric use.

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Determination of artesunate using reversed-phase HPLC at increased temperature and ELSD detection.

Artesunate (ART) determination can be performed by evaporative light scattering detection with mobile phase composed of CH(3)CN/HCOOH 0.01 M (40:60 v/v; pH 2.85). Evaporative light scattering detection instead of UV detection allowed to improve the sensitivity and the LOD. However, the evaporative light scattering detection response of dihydro-artemisinin appears weaker than for ART, whereas with UV detection the response of ART and dihydroartemisinin seemed similar. Constant analysis time was obtained on using the mobile phase with a flow rate of 0.5 mL/min and column temperature at 60 degrees C instead of 0.7 mL/min at room temperature. This led to less solvent consumption. Moreover, decrease in the flow rate and increase in the column temperature were advantageous for higher sensitivity with both evaporative light scattering detection and UV detection. ART determination in rectal gel and suppositories were compared with these different detection modes and similar results were obtained.

Analysis of fatty acid samples by hydrophilic interaction liquid chromatography and charged aerosol detector

HILIC/CAD techniques were used in analysis of samples containing fatty acids. Amine base column appeared to be the more retentive stationary phase compared to zwitterionic and BEH silica. The retention decreased with pH mobile phases changing from 3 to 5. Acetonitrile and acetone organic modifier were compared. Acetone gave higher eluotropic strength and better peak symmetry whereas acetonitrile led to higher efficiency. The retention decreased when ammonium acetate concentration increased from 5 to 20mM. The use of sub-2μm column did not show flat Van Deemter curves at high flow rates. A rapid separation of PGI2 and its main degradation product, 6-keto prostaglandin F1α was obtained in 1.6min with a Hypersil GOLD, 50mm×2.1mm, 1.9μm with; acetonitrile/acetate ammonium pH 5 at 20mM (85/15; v/v at 0.7ml/min).

Screening paediatric rectal forms of azithromycin as an alternative to oral or injectable treatment

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SIMULTANEOUS DETERMINATION OF ARTEMETHER AND AZITHROMYCIN IN SUPPOSITORIES BY REVERSED PHASE HPLC

Chromatographic parameter assessments for RP-HPLC-UV method development for the simultaneous analysis of artemether and azithromycin for the pharmaceutical analysis of a rectal coformulation currently under development for the treatment of malaria infected children. Using methanol based mobile phase for the analysis of both artemether and azithromycin provided a more robust method in terms of resolution and peak symmetry. The method validated for suppository used 80% methanol and 20% phosphate buffer 15 mM at pH 9. The UV detection was at 210 nm. The accuracy profiles indicated a method validation between 80–120% for both active pharmaceutical ingredients. The preparation process of the suppository was validated based on theoretical values of artemether and azithromycin present in the formulation; active pharmaceutical ingredients were homogenously distributed within the suppository.

In Vitro Ceftriaxone Stability at New-borns Rectal PH Assessed by UV and HPLC Methods

This study showed the comparison of UV spectroscopy and High Performance Liquid Chromatography (HPLC) for ceftriaxone stability. UV spectroscopy using wavelength ratio between 241 and 271 nm absorbance values can be used successfully as a screening technique in ceftriaxone stability investigations. Ion paring reversed phase – High Performance Liquid Chromatography provided more precise stability characterization. The HPLC conditions developed were in isocratic mode using an YMC ODS H80, 150 x 4.6 mm, 4 μm with a mobile phase composed by 40% of methanol and 60% of phosphate buffer (10 mM; pH 7.5) where tetrabutylammonium bromide was solubilized at 18 mM. Detection was performed with a diode array detector from 200 to 400 nm. Sample injection volume was at 5 μL. Methanol was selected because better symmetry of ceftriaxone peak than acetonitrile was obtained. Both methods were validated. The calibration curve and stability study was performed over a concentration range of 7.5 to 16.5 mg.L-1. 100% corresponded to the concentration of 15 mg.L-1. Intermediate precision was tested on 6 independent samples at concentrations corresponding to 100% (15 mg.L-1) on 6 consecutive days. These values were within the acceptance criteria of 2% and showed that both methods were precise. Accuracy of the method was evaluated analyzing three independent samples at concentrations corresponding to 100%. Recovery percentage calculated between the known concentration and the calculated concentration of ceftriaxone showed that the methods were accurate. Thus both methods were linear. The stability study was performed at 40°C as infants with sepsis are generally febrile. Over the rectal pH range recorded in sick infants, the stability of ceftriaxone was maximal at pH 7.5. Over 6 hours in a pH range of 6.5 to 8.5 less than 10% of ceftriaxone is degraded. However at pH 5.5, degradation occurred more rapidly and loss of drug was significant.