Journal of the Society of Powder Technology, Japan
The Journal of the Society of Powder Technology, Japan publishes valuable research papers in various fields related to powder technology and provides useful information to members. It publishes monthly original research papers and technical
papers as well as general articles that are useful for members. It also covers
reviews, overseas reports, doctoral thesis introduction and other materials in
various fields related to powder technology. It is widely known as the only
journal for the members who have keen interest in powder technology.
The flexible metal-organic frameworks (MOFs), which are a new type of porous material, exhibit unique adsorption behavior, and are expected to have a wide range of applications. However, to overcome the issue of low handling performance of flexible MOFs, it is necessary to establish a molding process. Although it is predicted that the flexible MOF particles and their aggregate structure should strongly affect the molding process, the effect on the particularly unique adsorption behavior is still unknown. In this study, the effect of the aggregate structure of flexible MOF particles on the uniaxial compression process was investigated experimentally and numerically. It was demonstrated that hollow-structured aggregates maintained the best adsorption properties. In addition, numerical analysis revealed that the force applied to the particles was reduced in hollow-structured aggregates. These would be useful results for the practical application of flexible MOF particles.
Mai Yoshizumi, Kaeko Araki, Masakazu Enomura, Hidenobu Murata, Atsushi Nakahira
Cerium oxide nanoparticles were synthesized using the Forced Thin-Film Type Reactor (FTFR). The precipitation solution was changed from aqueous sodium hydroxide to ammonia solutions. By adjusting the mixing ratio of trivalent and tetravalent cerium ions in the solutions and varying the cerium ion concentration, the shape of the particles varied from spherical to truncated octahedron and irregular shape to cuboidal to truncated octahedral. It was estimated that the change in particle shape could be attributed to the difference in the concentration of dissolved oxygen and hydroxide ion in each solution.
Nanoemulsions have been employed as one of the methods for nano-dispersing poorly water-soluble drugs in mucus. However, most liquid suspension such as the emulsions is washed by the clearance effect on the mucus surface. This study examined the spontaneous emulsification formulation using porous polymer microparticles with mucosal adhesion as the technology for drug permeation enhancement. The nanoemulsion formation expected in this technology could be realized using medium-chain fatty acid triglyceride as the oil component. Moreover, the spontaneous emulsification and the diffusion of the nanoemulsion in mucus proceeded smoothly by using porous particles composed of anionic polymers that have little interaction with mucus components, because mucus is composed of anionic polymer, mucin. It was anticipated that the fine emulsions prepared by this method would enhance drug transport in mucus.
Sana Nakamura, Yasushi Mino, Koichi Nakaso, Kuniaki Gotoh, Hiroshi Satone
Flowability of wet granules is an important indicator for design and control of manufacturing processes. In this study, we aimed to develop a method to evaluate the flowability with simple equipment and operation. We measured the stirring torque under constant normal stress and the resistance force acting on the plate penetrating into the granules layer. The stirring operation did not properly measure the flowability of strongly cohesive wet granules because voids around the stirring impeller were generated. The penetration operation was able to evaluate the flowability over a wide range of water content conditions by two different indices. Furthermore, the theory of bearing capacity was applied to the penetration tests.
Our study described a new annealing approach for dry-coated formulations, which includes heating of the dosage forms in plasticizer vapor. First, coated tablets were produced by V-shaped blending of tablets and polymer particles without any solvents. Second, these tablets were placed in a desiccator, in which triethyl citrate in liquid state was pre-charged, followed by heating at various temperatures. The resulting tablets were characterized. The polymer particles layered on the surface of tablets coalesced by heating at 80°C or more in plasticizer vapor, indicating that using plasticizer vapor could lower heating temperature required for film formation of coated polymer. The weight of polymer compacts increased by heating in plasticizer vapor as heating temperature increased. These data were correlated with vaporization rate of the plasticizer, indicating that plasticizer in gas state was absorbed in polymer particles, promoting film formation due to a decrease in glass transition temperature of the polymer.