Publications by authors named "Ruud Verrijk"

Probabilistic modeling using influence networks is an efficient, intuitive, and easy to communicate strategy in the development of complex pharmaceutical products. This study was aimed to use a risk-based approach to explore the complex interactions between product and process design parameters affecting size and shape of the particles in injectable aqueous crystalline suspensions (ACS). Based on a risk assessment, a design of experiments (DOE) was applied to evaluate the most important parameters, i.

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Solid form diversity of raw materials can be critical for the performance of the final drug product. In this study, Raman spectroscopy, image analysis and combined Raman and image analysis were utilized to characterize the solid form composition of a particulate raw material. Raman spectroscopy provides chemical information and is complementary to the physical information provided by image analysis.

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Objective: Chronic suppurative otitis media (CSOM) is a chronic infectious disease with worldwide prevalence that causes hearing loss and decreased quality of life. As current (antibiotic) treatments often unsuccessful and antibiotic resistance is emerging, alternative agents and/or strategies are urgently needed. We considered the synthetic antimicrobial and anti-biofilm peptide P60.

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The release of drugs from poly(lactic-co-glycolic acid) (PLGA) microparticles depends to a large extent on the porosity of the particles. Therefore, porosity determination of PLGA microparticles is extremely important during pharmaceutical product development. Currently, mercury intrusion porosimetry (MIP) is widely used despite its disadvantages, such as the need for a large amount of sample (several hundreds of milligrams) and residual toxic waste.

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The purpose of this study was to explore the potential of flow imaging microscopy to measure particle size and agglomeration of poly(lactic-co-glycolic acid) (PLGA) microparticles. The particle size distribution of pharmaceutical PLGA microparticle products is routinely determined with laser diffraction. In our study, we performed a unique side-by-side comparison between MFI 5100 (flow imaging microscopy) and Mastersizer 2000 (laser diffraction) for the particle size analysis of two commercial PLGA microparticle products, i.

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A potent anti-vascular endothelial growth factor (VEGF) biologic and a compatible delivery system were co-evaluated for protection against wet age-related macular degeneration (AMD) over a 6month period following a single intravitreal (IVT) injection. The anti-VEGF molecule is dimeric, containing two different anti-VEGF domain antibodies (dAb) attached to a human IgG1 Fc region: a dual dAb. The delivery system is based on microparticles of PolyActive™ hydrogel co-polymer.

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Angiogenesis induced by growth factor-releasing microspheres can be an off-the-shelf and immediate alternative to stem cell therapy for acute myocardial infarction (AMI), independent of stem cell yield and comorbidity-induced dysfunction. Reliable and prolonged local delivery of intact proteins such as VEGF is, however, notoriously difficult. Our objective was to create a platform for local angiogenesis in human-sized hearts, using polyethylene-glycol/polybutylene-terephthalate (PEG-PBT) microsphere-based VEGF165A delivery.

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Article Synopsis
  • Locteron is a new formulation of recombinant interferon-alpha2b designed for controlled release, tested on 27 volunteers with various dosages compared to pegylated interferon and placebo.
  • Serum levels of IFN-alpha2b from Locteron remained high for up to 14 days, with a longer elimination half-life than pegylated interferon.
  • Locteron showed fewer and milder side effects like flu-like symptoms compared to pegylated interferon, suggesting it could be a promising treatment for hepatitis C with bi-weekly dosing.
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Docetaxel (DCTX) and paclitaxel (PTX) are very potent anti-cancer drugs, but the currently marketed formulations, Taxotere and Taxol, respectively, are associated with vehicle-related toxicity. An attractive alternative to formulate these hydrophobic cytotoxic agents are polymeric micelles. In this study, the loading of taxanes into oligomeric micelles composed of mPEG750-b-oligo(epsilon-caprolactone)5 (mPEG750-b-OCL5) with a hydroxyl (OH), benzoyl (Bz) or naphthoyl (Np) end group was investigated.

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The chemical and enzymatic degradation of monodisperse oligo(epsilon-caprolactone) (OCL) and its amphiphilic block oligomer with methoxy poly(ethylene glycol) (mPEG) were investigated in order to obtain insight into the degradation of mPEG-b-OCL micelles. Hydrolytic degradation was studied as function of pH and dielectric constant of the medium, and enzymatic degradation was investigated at different enzyme and substrate concentrations. The degradation was monitored by HPLC and MS, and the micelle destabilization with DLS.

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Micro- and nanospheres composed of biodegradable polymers show promise as versatile devices for the controlled delivery of biopharmaceuticals. Whereas important properties such as drug release profiles, biocompatibility, and (bio)degradability have been determined for many types of biodegradable particles, information about particle degradation inside phagocytic cells is usually lacking. Here, we report the use of confocal Raman microscopy to obtain chemical information about cross-linked dextran hydrogel microspheres and amphiphilic poly(ethylene glycol)-terephthalate/poly(butylene terephthalate) (PEGT/PBT) microspheres inside RAW 264.

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The aim of this study was to investigate the in vitro degradation of hydroxyl ethyl methacrylated dextran (dex-HEMA) microspheres. Dextran microspheres were incubated in phosphate buffer pH 7.4 at 37 degrees C, and the dry mass, mechanical strength, and chemical composition of the microspheres were monitored in time.

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To optimize and predict the release of proteins from biodegradable microspheres based on crosslinked dextran, a fundamental understanding of the mechanisms controlling their release is necessary. For that purpose, a mathematical model has been developed to describe the release of proteins from these hydrogel-based microspheres. A kinetic Monte Carlo scheme for the degradation of a small domain inside the microsphere was developed.

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Methoxypoly(ethylene glycol)-b-oligo-L-lactate (mPEG-b-OLA) diblock oligomers with monodisperse OLA blocks were obtained by fractionation of polydisperse block oligomers using preparative HPLC. The fractionated oligomers were composed of an mPEG block with a molecular weight of 350, 550, or 750 and an OLA block with a degree of polymerization of 4, 6, 8, or 10. The diblock oligomers with a low PEG content were fully amorphous, with glass transition temperatures ranging from -60 to -20 degrees C, indicating that the blocks were miscible.

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New peptides for lipopolysaccharide (LPS) and lipoteichoic acid (LTA) neutralization in upper respiratory tract infections were developed and evaluated in terms of efficacy and safety for application in humans. Based on the sequence of the human antimicrobial peptide LL-37 we developed and investigated length variants, substitution analogues and modifications to stabilize the peptides to prevent enzymatic degradation and to improve efficacy. The most promising peptide appears P60.

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Biopharmaceuticals are pharmaceutical products consisting of (glyco)proteins. Nowadays a substantial part of the FDA-approved drugs belong to this class of drugs. Biopharmaceuticals deserve special attention as they have a number of characteristics that set them aside from low molecular weight drugs.

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