Preparation of a Solid Dispersion by a Dropping Methodto Improve the Rate of Dissolution of Meloxicam

Application of a solid dispersion system is one of the methods used to increase the bioavailability of poorly water-soluble drugs. Adaptation of the dropping method from the chemical industry as a formulation procedure may help the scaling-up process and simplify the formulation of poorly water-soluble compounds. Meloxicam (ME), a nonsteroidal anti-inflammatory drug that is poorly soluble in water, and polyethylene glycol (PEG) 4000, a water-soluble carrier, were formulated by using a dropping method in an attempt to improve the dissolution of ME. Pure ME and physical mixtures and tablets of ME–PEG 4000 (1:3 ratio) were compared as regards their dissolution with samples formulated by the dropping method. The results revealed that the round particles (solid drops) exhibited a higher dissolution rate than those of the physical mixtures, tablets, and pure ME. Self-modeling curve resolution (SMCR) as a chemometric method was used to evaluate X-ray powder diffractometry (XRPD) data. The results demonstrated the presence of a new crystalline phase in the solid dispersion, which can help the fast and quantitative dissolution from the solid drops. The round particles can be adapted to individual therapy by using a distributor.     

A new nickel metal organic framework (Ni-MOF) porous nanostructure as a potential novel electrochemical sensor for detecting glucose

Journal of Porous Materials - A Ni-MOF-based novel electrochemical sensor was synthesized with high surface area of 1381 m2/g, significant porosity of 1.14–9.6 nm and average...     

Preparation of turmeric-derived sulfur-functionalized carbon dots: antibacterial and antioxidant activity

Journal of Materials Science - The work describes the preparation of carbon dots using turmeric as the carbon source and their functionalization with sulfur to enhance the functionality. The...     

Preparation of a solid dispersion by a dropping method to improve the rate of dissolution of meloxicam

Application of a solid dispersion system is one of the methods used to increase the bioavailability of poorly water-soluble drugs. Adaptation of the dropping method from the chemical industry as a formulation procedure may help the scaling-up process and simplify the formulation of poorly water-soluble compounds. Meloxicam (ME), a nonsteroidal anti-inflammatory drug that is poorly soluble in water, and polyethylene glycol (PEG) 4000, a water-soluble carrier, were formulated by using a dropping method in an attempt to improve the dissolution of ME. Pure ME and physical mixtures and tablets of ME-PEG 4000 (1:3 ratio) were compared as regards their dissolution with samples formulated by the dropping method. The results revealed that the round particles (solid drops) exhibited a higher dissolution rate than those of the physical mixtures, tablets, and pure ME. Self-modeling curve resolution (SMCR) as a chemometric method was used to evaluate X-ray powder diffractometry (XRPD) data. The results demonstrated the presence of a new crystalline phase in the solid dispersion, which can help the fast and quantitative dissolution from the solid drops. The round particles can be adapted to individual therapy by using a distributor.     

Effect of yttria on sintering and microstructural behavior of reaction sintered mullite based on bauxite,fly ash and precipitated silica

The present investigation on the effect of Y₂O₃ towards the sintering behavior of mullite compacts revealed that rapid mullitization occurred through nucleation and normal grain growth due to the formation of yttrious silicate glassy phase. The intergranular voids were progressively eliminated by yttrious silicate glass leading to significant decrease in porosity with the corresponding remarkable rise in mechanical strength of sintered compacts. The uniform dispersion of microfine corundum grains into the mullite matrix with 1.5% Y₂O₃ content was noticed during sintering at 1550?°C and above.     

Hydrophobicity optimization of polypropylene hollow fiber membrane by sol–gel process for CO<Subscript>2</Subscript> absorption in gas–liquid membrane contactor using response surface methodology

In membrane technology, wettability is one of the most crucial points for successful industrial application of membrane contactors. To solve this issue, a non-wetting polypropylene (PP) hollow fiber membrane was prepared by the incorporation of modified silica nanoparticles (CH₃SiO₂) synthesized through sol–gel process on the surface and the cross-section of the membrane. Tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) were used as precursor and hydrophobic agent, respectively, to synthesize CH₃SiO₂ nanoparticles (NPs). In preparation procedure of NPs, the influential parameters including MTES/TEOS and H₂O/TEOS molar ratios and NH₄OH concentration were optimized using central composite design of response surface method (RSM) by considering contact angle (CA) as response variable. The CA of 168° was obtained using analysis of variance (ANOVA) when the MTES/TEOS molar ratio, H₂O/TEOS molar ratio and NH₄OH concentration were, respectively, 3.774, 8.000 and 0.511 M. ATR-FTIR, FE-SEM, mechanical strength and porosity measurements were used to characterize the optimum membrane. The neat and modified membranes were also tested for the CO₂ absorption process in a gas–liquid membrane contactor system. The CO₂ absorption flux of modified membrane almost remained constant within 30 days, while the neat membrane slightly suffered from wetting problem, resulted in a continuous decline in the CO₂ flux.     

Grain Refinement through Shear Banding in Severely Plastic Deformed A206 Aluminum Alloy

The present work is conducted to study the microstructure and texture evolutions in an as‐cast A206 aluminum alloy after applying severe plastic deformation. Toward this end, the material is severely deformed through accumulative back extrusion (ABE) technique at 200 °C and followed by assessing the room temperature mechanical properties of the products. The macro shear‐bands formation in the highly strained regions can result in grain refinement through the geometric dynamic recrystallization mechanism. A significant refinement is also characterized within the micro shear‐bands; this is attributed to the intensified substructure development and the occurrence of continuous dynamic recrystallization. The corresponding inverse pole figure maps show similar orientation for these newly refined grains with the parent ones. A random texture is produced through sub‐grain rotation to dissimilar orientation at the intersection of micro‐bands. The assessment of mechanical properties of the processed materials reveal significant increase in both yield and ultimate tensile strength values. The hardness profiles also demonstrate a relatively homogenous microstructure after three and five ABE passes holding a mean hardness value of 183 Vickers.     

Microwave absorption properties of double‐layer nanocomposites based on polypyrrole/natural rubber

Thin flexible double‐layer microwave absorbers have been fabricated based on polypyrrole (PP)/natural rubber (NR) nanocomposites and their reflection loss characteristics were studied in the range of 8–18 GHz. The PP‐NR matrix was prepared from PP and NR in the ratio of 15:85. The polymers used in this work not only serve as the matrix but also improve the microwave absorption properties. The first layer or impedance matching layer which is comprised of graphite, Fe₃O₄, and TiO₂ nanoparticles in PP‐NR transmits the electromagnetic (EM) wave without reflection. The second layer which is made up of PP‐NR filled with Fe₃O₄ disperses the EM wave energy. The design of a double‐layer nanocomposite is a method to match the wave impedance, enhance wave absorption ability, and broaden the absorption frequencies. In order to achieve high absorption properties, the EM parameters such as permittivity, permeability, and thickness were controlled precisely according to quarter‐wave plate. The morphology, absorption properties, scattering parameters, thermal and wetting characteristics of double‐layer nanocomposites were investigated. The minimum reflection loss (R_L) was ?32 dB at 12.1 GHz and the absorbing bandwidth in which the R_L < ?10 dB was 9 GHz for optimum specimen with 2 mm thickness. For this specimen, the contact angle was equal to 118.7° with water as the liquid. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46565.