Influence of compacted hydrophobic and hydrophilic colloidal silicon dioxide on tableting properties of pharmaceutical excipients.

The effect of noncompacted and compacted hydrophilic as well as hydrophobic colloidal silicon dioxide (CSD) on tableting properties of three different pharmaceutical excipients used for direct compression, namely, Avicel PH 101, Starch 1500, and Tablettose 80, was investigated. Binary powder mixtures containing 0.5% CSD and 99.

Mechanism of glidants: investigation of the effect of different colloidal silicon dioxide types on powder flow by atomic force and scanning electron microscopy.

The effect of hydrophilic and hydrophobic colloidal silicon dioxide types (CSD) on the flow characteristics of microcrystalline cellulose (MCC) under different mixing conditions was macroscopically measured using the angle of repose method, the bulk and tapped densities. CSD ameliorated the flow characteristics in general, but hydrophobic CSD was more effective compared to the hydrophilic types under gentle mixing conditions. The macroscopic effect was explained on the particle level by scanning electron (SEM) and atomic force microscopy (AFM) studies.

Synthesis of mesoporous silica monoliths with embedded nanoparticles.

Mesostructured silica-nanoparticle monolithic composites have been synthesized by dispersing prefabricated nanoparticles of gold or zeolite (silicalite) in ethanolic reaction mixtures containing SiCl4 and a Pluronic triblock copolymer template. Whereas silicalite nanoparticles were used directly, surface functionalization of the gold nanoparticles with either primed silicate ions or a discrete 3-5-nm-thick silica shell was required to increase the interfacial compatibility with the hydrophilic poly(ethylene oxide) blocks. Under these conditions, the resulting monoliths consisted of distributed nanoparticles within an ordered mesostructured silica matrix.