Liquid-liquid phase separation (LLPS) that occurs during crystallization is problematic because it has various adverse effects. In this study, water/ethanol/butylparaben solutions were evaporated and the phase change process was observed under an optical microscope to investigate the effects of initial composition and evaporation rate on the solution morphology. It was found that LLPS could be avoided by selecting an initial composition such that the evaporation path does not pass through the LLPS region. It was also found that the probability of LLPS occurrence, the size of the dispersed phase, and the final morphology of the crystals differ depending on how the evaporation path crosses the LLPS region. Furthermore, when the evaporation pathway passed near the boundary of the LLPS region, if the evaporation rate was high, even if LLPS occurred, the crystals returned to one phase during crystallization and crystallization could be carried out as usual. Thus, we obtained non-equilibrium-specific findings that are not indicated by the phase diagram alone.

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.

Our recent study on the design of interparticle photo-cross-linkable Pickering emulsion were briefly reviewed. The emulsion can be designed by dispersing ceramic particles in continuous phase containing limited amounts of monomers, adding dispersing phase, and conducting vigorous mixing. Photocurable Pickering emulsion was successfully prepared when functionalized polyethyleneimine was used as reactive polymer dispersant. Owing to the high flowability and photo-curability, the designed Pickering emulsion can be applied to various structuring process such as photo-molding, green machining, and stereolithographic 3D printing. Further, the 3D structured ceramic porous green bodies were debindable and sinterable through rapid heating profiles without occurring structural collapse.

Highly macro-porous ceramics with relatively dense surfaces have been successfully fabricated using the powder-based direct foaming process that employs thermosetting phenolic resin powder as foaming agent and binder for the ceramic powder. When foaming on the surface is suppressed by using filter paper, highly porous structure with denser surface could be simultaneously fabricated in one foaming process. Macro-porous ceramic with denser surface is obtained through conventional sintering process. This article briefly reviews these fabrication processes and key factors affecting the porous structure. The highly macro-porous ceramics with a denser surface are also characterized by bending strength measurement and microstructural observation.