Preparation of nano- and submicron sized particles is a useful method for solubility improvement of poorly water-soluble drugs of oral dosage forms by increasing surface area. In this study, a multi-ring type wet milling system was used to micronize poorly water-soluble drugs, and its performance was investigated. It was confirmed that particle size was easy to control by the operating conditions with adding a little quantity of milling stabilizer. Also, it was considered that a low content of additives is very advantageous in regard to the choice of formulation and characteristics of the final drug products. As a result, the dissolution profiles of ibuprofen and indomethacin which were milled in this study were faster than the non-milled original drugs, and their suspensions were stable for a week without having agglomeration, and the crystallites of the milled drugs were maintained. Also, the usage of the multi-ring type wet milling system would make easy to determine the scale-up operating conditions from the point of view of the milling mechanism, and a high content of drug substances is advantageous for the manufacturing.

Powdery-type foundation, one of the typical makeup cosmetics, is required to form even and smooth powdered layer on the skin. Such layer is achieved by well-dispersion of foundation particles. However, particles of titanium-dioxide and iron-oxide, both of which are vital foundation components, easily aggregate on the skin. In order to solve this problem, this study aimed to develop novel low-aggregation titanium-iron oxide particle. Experiments showed that our developed particle, in which titanium dioxide is coated with iron oxide, achieved well-dispersion due to its unique structure and shape. The experiments also showed that such a particle property results in an effective coverage of color-unevenness and pores of the facial skin.

The large band gap of most metal oxides restricts their photocatalytic activity to the ultraviolet (UV) range of the solar spectrum. Almost 5% UV is present in the whole solar spectrum so that designing metal oxide semiconductors with the capability of absorbing visible light is long attempted. The large band gap of metal oxides can be reduced by methods like doping, however, photocatalytic activity is not necessarily enhanced due to the defect-induced carrier recombination losses. In recent years, we have focused on the high-pressure phases of wide band gap semiconductors, which theoretically possess narrow band gaps, being able to absorb visible light. In this review, high-pressure phases of well-known semiconductors like TiO₂, ZnO, and Y₂O₃ have been stabilized by applying a severe plastic deformation method, and their photocatalytic properties are evaluated.