Query: magnesium dihydroxide

title: Resveratrol Supported on Magnesium DiHydroxide (Resv@MDH) Represents an Oral Formulation of Resveratrol With Better Gastric Absorption and Bioavailability Respect to Pure Resveratrol
abstract: Resveratrol attracts great interest because of the plethora of in vitro effects at the micromolar concentration range. Unfortunately, these effects are difficult to establish in vivo, due to the low concentration of resveratrol reached. This discrepancy is due to the molecules low solubility in water that favors the propensity for an intestinal absorption rather than in the gastric compartment. To address these challenges, we developed a Solid Dispersion of Resveratrol Supported by Magnesium Di Hydroxide formulation (Resv@MDH) This formulation displays increased water solubility and better bioavailability relative to pure resveratrol in the rabbit animal model. In our study, we evaluated the pharmacokinetics profile of resveratrol in six healthy human subjects following 180 mg of oral resveratrol administration, derived from Resv@MDH or pure resveratrol. Free resveratrol was evaluated in the whole blood sample by using HPLC MS/MS. In comparison with pure resveratrol that displays an increase of the maximum plasma concentration, Cmax at about 90 min and 2 mM, Resv@MDH displays an earlier peak of resveratrol concentration with an increase of Cmax at about 30 min and 6 mM. The different kinetics suggest a main gastric route for resveratrol absorption from Resv@MDH, where, because of its improved dissolution rate, there seems to be a higher propensity for an acidic environment, as opposed to that with pure resveratrol. This conclusion is also supported by the numerical simulation analysis, which considers the principal steps during the oral route administration. Moreover, there is a 2 fold increase in the amount of free resveratrol with respect to pure resveratrol confirming a better bioavailability observed in the animal model. The characteristic feature of the pharmacokinetic profile of Resv@MDH implies that the beneficial properties of resveratrol in human health should be capitalized on it.

title: Resveratrol supported on magnesium DiHydroxide (Resv@MDH, REVIFAST) represents an improved formulation of resveratrol with fast absorption and bioavailability in humans

title: Solid Dispersion of Resveratrol Supported on Magnesium DiHydroxide (Resv@MDH) Microparticles Improves Oral Bioavailability
abstract: Resveratrol, because of its low solubility in water and its high membrane permeability, is collocated in the second class of the biopharmaceutical classification system, with limited bioavailability due to its dissolution rate. Solid dispersion of resveratrol supported on Magnesium DiHydroxide (Resv@MDH) was evaluated to improve solubility and increase bioavailability of resveratrol. Fluorimetric microscopy analysis displays three types of microparticles with similar size: Type 1 that emitted preferably fluorescence at 445 nm with bandwidth of 50 nm, type 2 that emitted preferably fluorescence at 605 nm with bandwidth of 70 nm and type 3 that is non fluorescent. Micronized pure resveratrol displays only microparticles type 1 whereas type 3 are associated to pure magnesium dihydroxide. Dissolution test in simulated gastric environment resveratrol derived from Resv@MDH in comparison to resveratrol alone displayed better solubility. A 3 fold increase of resveratrol bioavailability was observed after oral administration of 50 mg/kg of resveratrol from Resv@MDH in rabbits. We hypothesize that type 2 microparticles represent magnesium dihydroxide microparticles with a resveratrol shell and that they are responsible for the improved resveratrol solubility and bioavailability of Resv@MDH.

title: Thermal degradation of polyesters filled with magnesium dihydroxide and magnesium oxide
abstract: Magnesium dihydroxide (MDH) was evaluated as char promoter into different polymers exhibiting various chemical structures. Char promotion was characterized using thermogravimetric analysis and pyrolysis combustion flow calorimetry. Gases released during pyrolysis were identified using pyrolysis coupled gas chromatography/mass spectrometry and thermogravimetric analysis coupled Fourier transform infrared spectroscopy. Relationships between the MDH effect (according to the char content and its thermal stability) and the chemical structure of the host polymers were identified. It was shown that MDH can be a good char promoter for aromatic polyesters such as polybutylene terephtalate and polyethylene terephtalate. Char promotion can be considered as one of the main mode of action of MDH at low or moderate filler content. An optimum was observed at approximately 20wt. of MDH. Magnesium oxide was also studied as substitute to MDH to avoid hydrolysis phenomena due to the water release. But it was demonstrated that MDH was more efficient as a char promoter for polybutylene terephtalate than magnesium oxide.

title: Effect of Magnesium Dihydroxide on Bleaching of Thermomechanical Pulp Made from Pinus densiflora

title: Effect of Sodium Hydroxide and Magnesium Dihydroxide on Bleaching of Chemithermomechanical Pulp Made from Pinus densiflora

title: Effect of magnesium dihydroxide nanoparticles on thermal degradation and flame resistance of PMMA nanocomposites
abstract: The influence of magnesium dihydroxide (MDH) nanoparticles on thermal degradation and fire behavior of poly(methyl methacrylate) (PMMA) has been investigated by thermogravimetric analysis (TGA) cone calorimeter, and pyrolysis combustion flow calorimeter (PCFC) tests, respectively. MDH nanoparticles with either lamellar or fibrous shape have been synthesized via a sol gel technique and characterized by transmission electron microscopy (TEM) and X ray diffraction analysis. PMMA MDH nanocomposites have been prepared by melt blending the recovered MDH nanoparticles within PMMA at different loadings (5, 10, and 20 wt% MDH) According to TGA results, the incorporation of lamellar or fibrous MDH nanoparticles into PMMA leads to a significant improvement in PMMA thermal stability, both under air and inert atmosphere. The results obtained by PCFC and cone calorimeter tests show an important decrease in the peak of heat release rate (pHRR) concomitant with charring during the combustion. Lamellar MDH nanoparticles were found to be more efficient than fibrous MDH nanoparticles.

title: New trends in flame retardant additives for polymeric materials: synthetic tailored geometry magnesium dihydroxide nanoparticles

title: Synthesis of Magnesium Dihydroxide Hybrid Nanocomposites via ATRP
abstract: Several hybrid nanocomposites consisting of a magnesium dihydroxide (MDH) core and tethered poly(meth)acrylate chains were synthesized via atom transfer radical polymerization (ATRP) The hydroxyl groups on the surface of the MDH particles were modified by reaction with 2 bromopropionyl or 2 bromoisobutyryl bromide to attach ATRP initiator moieties to the particle. n Butyl acrylate, methyl methacrylate, dodecyl methacrylate and octadecyl methacrylate were polymerized from the functionalized MDH particles using the "grafting from" technique. MDH is a representative of flame retardants which release water when heated. The polymer chains attached to MDH particles will provide the composites with enhanced compatibility in blends with common polymers. The efficiency of attachment, and the molecular weights and polydispersity of the polymers attached to the nanoparticles were investigated by GPC and TGA after post polymerization cleavage from the particles. AFM was used to analyze morphologies and structure of the composites.

title: Synthesis of Magnesium Dihydroxide Hybrid Nanocomposites via ATRP
abstract: Several hybrid nanocomposites consisting of a magnesium dihydroxide (MDH) core and tethered poly(meth)acrylate chains were synthesized via atom transfer radical polymerization (ATRP) The hydroxyl groups on the surface of the MDH particles were modified by reaction with 2 bromopropionyl or 2 bromoisobutyryl bromide to attach ATRP initiator moieties to the particle. n Butyl acrylate, methyl methacrylate, dodecyl methacrylate and octadecyl methacrylate were polymerized from the functionalized MDH particles using the "grafting from" technique. MDH is a representative of flame retardants which release water when heated. The polymer chains attached to MDH particles will provide the composites with enhanced compatibility in blends with common polymers. The efficiency of attachment, and the molecular weights and polydispersity of the polymers attached to the nanoparticles were investigated by GPC and TGA after post polymerization cleavage from the particles. AFM was used to analyze morphologies and structure of the composites.