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A newly developed beads mill was used to create well-dispersed suspensions of TiO2 (titania) nanoparticles in methyl methacrylate (MMA) and TiO2−PMMA nanocomposites were synthesized by subsequent polymerization of the TiO2−MMA suspension. Beads milling successfully broke up titania nanoparticle agglomerates with the addition of the coupling agent (3-acryloxypropyl) trimethoxysilane (APTMOS) to the titania−MMA suspension. Agglomerated particles were broken up into primary particles as small as 10 nm in suspensions with nanoparticle mass fractions as high as 0.05. Well-dispersed suspensions of titania nanoparticles had reduced UV transmission but visible light transmittance similar to pure MMA. TEM images showed that the milled nanoparticles remained well dispersed in titania−PMMA nanocomposites, and the addition of titania nanoparticles to PMMA increased the PMMA thermal stability. Spin-coated titania−PMMA films had higher refractive indices than pure PMMA films, with film of higher titania weight percent having higher refractive indices.

To improve the dissolution and oral absorption properties of probucol, a novel wet-milling process using the ULTRA APEX MILL was investigated. The particle size of bulk probucol powder was 17.1 µm. However, after wet-milling with dispersing agents such as Gelucire 44/14, Gelucire 50/13, vitamin E-TPGS, and Pluronic F-108, the probucol particle sizes decreased to about 77-176 nm. Scanning electron microscopy (SEM) analysis also suggested that the probucol particles were successfully milled into the nanometer range. An in vitro dissolution study showed that the dissolution rates of all nanopowders were several folds higher than those of the corresponding mixed powders. When orally administered to rats, the AUC values of probucol nanopowders treated with Gelucire 44/14 and 50/13, and vitamin E-TPGS were about 3.06-3.54-folds greater than that of the bulk powder. Therefore, through this study, we have developed a new pharmaceutical technique to improve the dissolution rate and oral absorption of probucol using the ULTRA APEX MILL by wet-milling with various dispersing agents.

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