The work was aimed at evaluating the efficiency of multifunctional magnesium aluminosilicate materials (MAS) as a novel glidant in solid dosage forms. MAS are known for their very low cohesive interactions and their utilization could avoid the disadvantages associated with conventional glidant usage. Flow properties of several mixtures comprising a model excipient (microcrystalline cellulose) and a glidant were characterized using a powder rheometer FT4. The mixtures were formulated to represent effects of glidant types, various levels of glidant loading, particle size and mixing time on flow properties of the model excipient. Pre-conditioning, shear testing, compressibility, flow energy measurements and an additional tapping test were carried out to monitor flow properties. Mixtures were analyzed employing scanning electron microscopy, using a detector of back-scattered electrons to identify a mechanism of MAS towards improving the mixture flow properties. All studied parameters were found to have substantial effects on mixture flow properties, but the effect of mixing time was much less important compared to mixtures based on traditional glidant. The mechanism of MAS glidant action was found to be different compared to that of traditional one, having less process sensitivity, so that MAS utilization as glidant could be advantageous for the formulation performance.
The mechanism of colloidal silica action to improve flow properties of pharmaceutical powders is known to be based on inter-particle force disruption by silica particles adhered to the particle surface. In the present article, the kinetic aspects of this action are investigated, focusing on non-spherical particles of different size. Blends comprising microcrystalline cellulose or calcium hydrogen phosphate dihydrate and colloidal silica were examined using powder rheometer. The blends were formulated to represent effects of particle size, surface texture, colloidal silica loading, and mixing time. Pre-conditioning, shear testing, compressibility, and flow energy measurements were used to monitor flow properties. Components and blends were analyzed using particle size analysis and scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS) and back-scattered electron (BSE) detection to determine surface particle arrangement. All studied parameters were found to have substantial effects on flow properties of powder blends. Those effects were explained by identifying key steps of colloidal silica action, which were found to proceed at substantially different rates, causing the flow properties change over time being dependent on the blend formulation and the component properties.
- MeSH
- časové faktory MeSH
- celulosa chemie MeSH
- chemie farmaceutická metody MeSH
- fosforečnany vápenaté chemie MeSH
- koloidy chemie MeSH
- mikroskopie elektronová rastrovací MeSH
- oxid křemičitý chemie MeSH
- pomocné látky chemie MeSH
- prášky, zásypy, pudry MeSH
- příprava léků metody MeSH
- reologie MeSH
- spektrometrie rentgenová emisní MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
