Dispersions in porous beds

Solid dispersions of carvedilol with porous silica.

Solid dispersion particles of carvedilol (CAR) were prepared with porous silica (Sylysia 350) by the solvent evaporation method in a vacuum evaporator to ensure an effective pore-filling procedure. Two sets were prepared, each with various amounts of CAR in solid dispersions, and with the pore-filling process differing each time. Set A was prepared by a one-step filling method and set B by a mu...

Physical Stability of Carvedilol in Solid Dispersions with Porous Silica

Adsorption onto silica-based high surface area carriers is a long known method of improvement drug dissolution rate, which has been described in early 1970s [1]. Porous silica has many silanol groups on its surface and can be used as pharmaceutical excipient, since it is regarded nontoxic after oral application. Due to its porous structure and large specific surface area, porous silica has a gr...

Characterization of Concentrated Dispersions and Emulsions, Liquids and Porous materials

Analysis of the volumetric phenomenon in porous beds subject to irradiation

This work examines the volumetric effect of convection within a packed bed in the presence of collimated irradiation. Using a modified P-1 approximation incorporating a local thermal nonequilibrium (LTNE) model, the energy transportation through convection and thermal conduction, and collimated and diffuse radiative transfer are investigated. The impact of pertinent parameters such as porosity ...

Injection of non-Newtonian dispersions of iron particles in porous media: modeling of clogging processes

In the context of groundwater remediation, an increasing interest was found towards nanoscale and microscale zero-valent iron particles (NZVI and MZVI, respectively). However, MZVI and NZVI are not stable when dispersed in water, due to fast aggregation and sedimentation. Consequently, the use of shear thinning solutions of green biopolymers have been recently studied as viscous carrier fluids ...