The results of this study report the novel use of electrostatic layer-by-layer nanoassembly of biocompatible nanoparticulate TiO2 multilayers to coat irregular nifedipine (NF) microcrystals to increase the photostability of the drug when exposed to simulated sunlight and to increase the dissolution rate and possibly the bioavailability of the drug after oral administration. The photostability of NF microcrystals (35 microm) coated with multiple bilayers of positively charged PDDA and negatively charged nanosized TiO2 particles (20-25 nm) was measured when exposed to an illuminance of 12 W/m2 corresponding to a light dose of 30 k lux or 25 W/m2 corresponding to light dose of 60 k lux. The dissolution rate of nifedipine from the coated microcrystals was measured in simulated gastric fluid containing 0.05% w/v polysorbate 80. Coating with one TiO2 layer increased the shelf life of nifedipine by 30 hours independent of the intensity of the light exposure. With an increase in the number of TiO2 layers; the photostability of the drug was enhanced even more. A TiO2 monolayer decreased the contact angle by 20 degrees for water and 33 degrees for the dissolution medium as compared with uncoated NF surfaces. This increase in wettability due to a decrease in contact angle increased the dissolution rate of nifedipine microcrystals coated with 1 PDDA/TiO2 bilayer 13-fold after 10 minutes, 5-fold after 1 hour, and 2-fold after 12 hours when compared to uncoated microcrystals. It is assumed that TiO2 increased the photostability because the nanoparticulate multilayers acts as a potential filter protecting the drug from damaging light rays reaching the drug crystals. The dissolution rate was increased because the hydrophilic TiO2 nanoparticles increased the aqueous wettability of the drug crystals thereby preventing aggregation in the dissolution medium. This ensured that the maximum drug surface area was exposed to the dissolution medium.
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http://dx.doi.org/10.1166/jnn.2006.421 | DOI Listing |
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January 2025
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
The scarcity of cost-effective and durable iridium-free anode electrocatalysts for the oxygen evolution reaction (OER) poses a significant challenge to the widespread application of the proton exchange membrane water electrolyzer (PEMWE). To address the electrochemical oxidation and dissolution issues of Ru-based electrocatalysts, an electron-donating modification strategy is developed to stabilize WRuO under harsh oxidative conditions. The optimized catalyst with a low Zirconium doping (Zr, 1 wt.
View Article and Find Full Text PDFInt J Nanomedicine
January 2025
Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, 72079, USA.
Poor aqueous solubility and bioavailability limit the translation of new drug candidates into clinical applications. Nanocrystal formulations offer a promising approach for improving the dissolution rate and saturation solubility. These formulations are applicable for various routes of administration, with each presenting unique opportunities and challenges posed by the physiological barriers.
View Article and Find Full Text PDFNature
January 2025
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, China.
The amount of methane released to the atmosphere from the Nord Stream subsea pipeline leaks remains uncertain, as reflected in a wide range of estimates. A lack of information regarding the temporal variation in atmospheric emissions has made it challenging to reconcile pipeline volumetric (bottom-up) estimates with measurement-based (top-down) estimates. Here we simulate pipeline rupture emission rates and integrate these with methane dissolution and sea-surface outgassing estimates to model the evolution of atmospheric emissions from the leaks.
View Article and Find Full Text PDFEnviron Technol
January 2025
Tekirdağ Metropolitan Municipality, TESKİ, Water and Sewerage Administration, Tekirdağ, Turkey.
This study explores variations in groundwater (GW) pH, conductivity, ammonium, iron, and manganese parameters to reveal prospective interactions having an impact on the dissolved metal concentrations. To this end, bivariate and partial correlation procedures were applied to the data to obtain incisive evaluation. Besides characterisation efforts, photocatalytic iron and manganese removal experiments were also carried out with Ni-doped TiO nano-composite thin films (TFs) on real GW samples.
View Article and Find Full Text PDFNanotechnol Sci Appl
January 2025
Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Universitas Padjadjaran, Sumedang, 45363, Indonesia.
Purpose: Improving drug solubility is crucial in formulating poorly water-soluble drugs, especially for oral administration. The incorporation of drugs into mesoporous silica nanoparticles (MSN) is widely used in the pharmaceutical industry to improve physical stability and solubility. Therefore, this study aimed to elucidate the mechanism of poorly water-soluble drugs within MSN, as well as evaluate the impact on the dissolution and physical stability.
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