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The physico-chemical properties of two anhydrous AZA forms and their interaction with typical pharmaceutical excipients were assessed by applying various methods (such as PXRD, HPLC, TG/DSC, IR, Raman, PL or UV-Vis) in order to highlight new directions for drug formulation. The stability assessment of AZA anhydrous forms I and II was performed in order to determine the risk of degradation of the active ingredient by accidental exposure to nonstandard conditions in the industrial environment, under different storage, transport or processing conditions. The benefits of form II include increased resistance to chemical degradation over a wide range of pH, but further control of storage and processing conditions is necessary to avoid polymorphic transformation into form I. The solubility assessment on the AZA solid forms in different environments that simulate the conditions of the gastrointestinal tract has the advantage of a significantly increased solubility of form II compared with the commercial form I due to the modification of the crystalline structure. In the case of capsules compared to AZA form I or II as powder, an improvement in their solubility was observed, promoted by the presence of one or more excipients in the formulation mixture. [ABSTRACT FROM AUTHOR]

Mixtures of nitrogen-doped titanium dioxide (TiO 2 :N) with different concentrations of Ag and/or SiO 2 particles (0.5, 1 and 2 wt.%) were prepared in solid state by mechanico-chemical interactions. Using UV-VIS spectroscopy, Raman scattering, photoluminescence (PL) and photoluminescence excitation (PLE), the influence of the particles on the host material is evaluated. UV-VIS spectroscopy studies indicate a TiO 2 :N band gap shift to the UV range with increasing concentrations of SiO 2 and Ag particles. PL intensities decrease with increasing concentrations of Ag and/or SiO 2 particles in the TiO 2 :N host matrix, which in turn could effectively restrict the electron and hole recombination. To explain these processes, the different de-excitation ways will be advanced, taking into account the energy levels diagram of TiO 2 :N/Ag, TiO 2 :N/SiO 2 and TiO 2 :N/Ag/SiO 2 systems. PLE spectra show a gradual decrease in their relative intensities after 165 min of continuous irradiation due to photosensitivity of TiO 2 :N. The plasmonic effect of Ag particles in the TiO 2 :N/Ag system is highlighted for the first time by PLE studies.