Enhancing dispersion of ultra-fine WC powders in aqueous media

Computer-driven formulation development of Ginsenoside Rh2 ternary solid dispersion

(20 S)-Ginsenoside Rh2 is a natural saponin derived from Panax ginseng Meyer (P. ginseng), which showed significantly potent anticancer properties. However, its low water solubility and bioavailability strongly restrict its pharmaceutical applications. The aim of current research is to develop a modified (20 S)-Ginsenoside Rh2 formulation with high solubility, dissolution rate and bioavailability by combined computational and experimental methodology. The "PharmSD" model was employed to predict the optimal polymer for (20 S)-Ginsenoside Rh2 solid dispersion formulations. The solubility of (20 S)-Ginsenoside Rh2 in various polymers was assessed, and the optimal ternary solid dispersion was evaluated across different dissolution mediums. Characterization techniques included the Powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). Molecular dynamics simulations were employed to elucidate the formation mechanism of the solid dispersion and the interactions among active pharmaceutical ingredient (API) and excipient molecules. Cell and animal experiments were conducted to evaluate the in vivo performance of the modified formulation. The "PharmSD" solid dispersion model identified Gelucire 44/14 as the most effective polymer for enhancing the dissolution rate of Rh2. Subsequent experiment also confirmed that Gelucire 44/14 outperformed the other selected polymers. Moreover, the addition of the third component, sodium dodecyl sulfate (SDS), in the ternary solid dispersion formulation significantly amplified dissolution rates than the binary systems. Characterization experiments revealed that the API existed in an amorphous state and interacted via hydrogen bonding with SDS and Gelucire. Moreover, molecular modeling results provided additional evidence of hydrogen bonding interactions between the API and excipient molecules within the optimal ternary solid dispersion. Cell experiments demonstrated efflux ratio (EfR) of Rh2 ternary solid dispersion was lower than that of pure Rh2. In vivo experiments revealed that the modified formulation substantially improved the absorption of Rh2 in rats. Our research successfully developed an optimal ternary solid dispersion for Rh2 with high solubility, dissolution rate and bioavailability by integrated computational and experimental tools. The combination of Artificial Intelligence (AI) technology and molecular dynamics simulation is a wise way to support the future formulation development.

Screening of Mono-, Di- and Trivalent Cationic Dopants for the Enhancement of Thermal Behavior, Kinetics, Structural, Morphological, Surface and Magnetic Properties of CoFe2O4-SiO2 Nanocomposites

CoFe₂O₄ is a promising functional material for various applications. The impact of doping with different cations (Ag⁺, Na⁺, Ca²⁺, Cd²⁺, and La³⁺) on the structural, thermal, kinetics, morphological, surface, and magnetic properties of CoFe₂O₄ nanoparticles synthesized via the sol-gel method and calcined at 400, 700 and 1000 °C is investigated. The thermal behavior of reactants during the synthesis process reveals the formation of metallic succinates up to 200 °C and their decomposition into metal oxides that further react and form the ferrites. The rate constant of succinates' decomposition into ferrites calculated using the isotherms at 150, 200, 250, and 300 °C decrease with increasing temperature and depend on the doping cation. By calcination at low temperatures, single-phase ferrites with low crystallinity were observed, while at 1000 °C, the well-crystallized ferrites were accompanied by crystalline phases of the silica matrix (cristobalite and quartz). The atomic force microscopy images reveal spherical ferrite particles covered by an amorphous phase, the particle size, powder surface area, and coating thickness contingent on the doping ion and calcination temperature. The structural parameters estimated via X-ray diffraction (crystallite size, relative crystallinity, lattice parameter, unit cell volume, hopping length, density) and the magnetic parameters (saturation magnetization, remanent magnetization, magnetic moment per formula unit, coercivity, and anisotropy constant) depend on the doping ion and calcination temperature.

Enhanced surface activity of activated carbon by surfactants synergism

Activated carbon (AC) modification has been intensively studied in order to design carbon electrodes with enhanced electrochemical performance. Hexadecyltrimethylammonium bromide (HDTMA) and Tween 80 were employed for enhancing the surface activity of AC via synergism. The synergistic effects of the mixed surfactants on AC surface activity in the light of interface behaviors were studied. Both field emission scanning electron micrographs and FTIR spectra indicated a successful adsorption of loaded surfactants. AC gained a good wettability originated from the surfactants, especially in the binary mixture (T80-HDTMA). The zeta potential results unveiled the positive charge density enhancement in the mixed surfactants system. Isoelectric point and point of zero charge implicate heterogeneous distribution of charges and the extent of surfactants treatment. Tween 80 displayed a significant size control dependence on AC particles. Electrochemical characterization revealed a higher specific capacitance and a decaying resistance of specific capacitance in AC-T80-HDTMA than AC-HDTMA at high concentration. In 5 g L⁻¹ of NaCl, AC-T80-HDTMA (0.01 : 0.01 mM) exhibits the specific capacitance of 209.79 F g⁻¹, at 0.8 V whereas AC-HDTMA (0.01 mM) and AC exhibited 186.5 F g⁻¹, 178.9 F g⁻¹, respectively. Moreover, the stability testing reveals a strong attachment of HDTMA in AC-T80-HDTMA than AC-HDTMA with the loss of 0.32% and 1.32%, respectively. The hypothetical synergistic mechanism of surfactants adsorption on the surface of AC was depicted as hydrophobic interaction and steric stabilization being the main keys for the synergy between cationic and nonionic surfactants. This study demonstrates the beneficial effects of mixed surfactants on AC electrode properties and discloses the impact on electrochemical performance.

Enhancement of AC surface activity by surfactants synergism for electrochemical applications.