The aim of the present study was to evaluate the importance of matrix flexibility of hot-melt extruded (HME) ethylene vinyl acetate (EVA) matrices (with vinyl acetate (VA) contents of 9%, 15%, 28% and 40%), through the addition of hydrophilic polymers with distinct swelling capacity. Polyethylene oxide (PEO 100K, 1M and 7M) was used as swelling agent and metoprolol tartrate (MPT) as model drug. The processability via HME and drug release profiles of EVA/MPT/PEO formulations were assessed. Solid state characteristics, porosity and polymer miscibility of EVA/PEO matrices were evaluated by means of DSC, X-ray tomography and Raman spectroscopy. The processability via HME varied according to the VA content: EVA 40 and 28 were extruded at 90°C, whereas higher viscosity EVA grades (EVA 15 and 9) required a minimum extrusion temperature of 110°C to obtain high-quality extrudates. Drug release from EVA matrices depended on the VA content, PEO molecular weight and PEO content, matrix porosity as well as pore size distribution. Interestingly, the interplay of PEO leaching, matrix swelling, water influx and changes in matrix porosity influenced drug release: EVA 40- and 28-based matrices extruded with PEO of higher MW accelerated drug release, whereas for EVA 15- and 9-based matrices, drug release slowed down. These differences were related to the distinct polymer flexibility imposed by the VA content (lower VA content presents higher crystallinity and less free movement of the amorphous segments resulting in a higher rigidity). In all cases, diffusional mass transport seems to play a major role, as demonstrated by mathematical modeling using an analytical solution of Fick's second law. The bioavailability of EVA 40 and 28 matrices in dogs was not significantly different, independent of PEO 7M concentration.
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http://dx.doi.org/10.1016/j.ejpb.2012.08.008 | DOI Listing |
Viruses
December 2024
Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK.
Seaweed-derived compounds are a renewable resource utilised in the manufacturing and food industry. This study focuses on an enriched seaweed extract (ESE) isolated from The ESE was screened for antiviral activity by plaque reduction assays against influenza A/Puerto Rico/8/1934 H1N1 (PR8), A/X-31 H3N2 (X31) and A/England/195/2009 H1N1 (Eng195), resulting in the complete inhibition of infection. Time of addition assays and FACS analysis were used to help determine the modes of action.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Research Group for Implantable Microsystems, Faculty of Information Technology & Bionics, Pázmány Péter Catholic University, H-1083 Budapest, Hungary.
The aim of this work is to incorporate lanthanide-cored upconversion nanoparticles (UCNP) into the surface of microengineered biomedical implants to create a spatially controlled and optically releasable model drug delivery device in an integrated fashion. Our approach enables silicone-based microelectrocorticography (ECoG) implants holding platinum/iridium recording sites to serve as a stable host of UCNPs. Nanoparticles excitable in the near-infrared (lower energy) regime and emitting visible (higher energy) light are utilized in a study.
View Article and Find Full Text PDFPharmaceutics
December 2024
Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA.
This study evaluates the efficacy of twin screw melt granulation (TSMG), and hot-melt extrusion (HME) techniques in enhancing the solubility and dissolution of simvastatin (SIM), a poorly water-soluble drug with low bioavailability. Additionally, the study explores the impact of binary polymer blends on the drug's miscibility, solubility, and in vitro release profile. SIM was processed with various polymeric combinations at a 30% / drug load, and a 1:1 ratio of binary polymer blends, including Soluplus (SOP), Kollidon K12 (K12), Kollidon VA64 (KVA), and Kollicoat IR (KIR).
View Article and Find Full Text PDFPharmaceutics
December 2024
Department of Pharmacy, Xuzhou Hospital of Traditional Chinese Medicine, Xuzhou 221003, China.
To design a multifunctional nanozyme hydrogel with antibacterial, photo-responsive nitric oxide-releasing, and antioxidative properties for promoting the healing of infected wounds. We first developed ultra-small silver nanoparticles (NPs)-decorated sodium nitroprusside-doped Prussian blue (SNPB) NPs, referred to as SNPB@Ag NPs, which served as a multifunctional nanozyme. Subsequently, this nanozyme, together with geniposide (GE), was incorporated into a thermo-sensitive hydrogel, formulated from Poloxamer 407 and carboxymethyl chitosan, creating a novel antibacterial wound dressing designated as GE/SNPB@Ag hydrogel.
View Article and Find Full Text PDFPharmaceutics
December 2024
College of Pharmacy, Dongguk University-Seoul, Dongguk-ro-32, Ilsan-Donggu, Goyang 10326, Republic of Korea.
Background/objectives: A sustained-release formulation of fenofibrate while enhancing drug dissolution with minimal food effect is critical for maximizing the therapeutic benefits of fenofibrate. Therefore, this study aimed to develop an effective solid dispersion formulation of fenofibrate for simultaneous enhancement in the extent and duration of drug exposure.
Methods: Fenofibrate-loaded solid dispersions (FNSDs) were prepared using poloxamer 407 and Eudragit RSPO at varied ratios via solvent evaporation.
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