The experimental phenomena that amorphous inosine (IR), α-IR, and IR dihydrate can form from IR aqueous solution and β-IR can crystallize from IR 70 vol% DMSO aqueous solution were explained using mid-frequency Raman difference spectra analysis.

The cyclic performance of flexible free-standing graphene-Fe₂O₃ hybrid sheet is considerably improved and was fabricated by a novel one-step hydrothermal process. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical workstation are performed to characterize the microstructure and electrochemical performance of the graphene-Fe₂O₃ hybrid sheet. At a current density of 200 mA·g⁻¹, the obtained product has a high initial discharge capacity of 1466 mAh·g⁻¹. The nanohybrids also exhibited a considerably high reversible capacity of 765 mAh·g⁻¹ and high Coulombic efficiency of 99.8% after 100 cycles, which benefited from the open 3D laminated nanostructure constructed by layered graphene paper and Fe₂O₃ nanoparticles. Therefore, the composite has excellent rate performance and stability and can be greatly extended as the anode material of lithium-ion batteries.

Andrographolide (ADG) is a typical poorly water-soluble drug, and a co-amorphous strategy was used here to improve its aqueous solubility. Co-amorphous systems of ADG and amino acids with a 1:1 molar ratio were screened via the neat ball milling method. L-lysine (Lys) and L-tryptophan (Trp) can be used as co-formers with ADG, forming a co-amorphous phase, which was confirmed by powder X-ray diffraction, IR and Raman spectroscopy. ADG-Trp showed poor solubility at 37 °C, which was close to that of raw ADG (0.08 mg·mL⁻¹). ADG-Lys showed unexpectedly enhanced solubility, at 0.5 mg·mL⁻¹ in the media of water and PBS (pH 7.4) and 0.3 mg·mL⁻¹ in the medium of HCl buffer (pH 1.2) at 37 °C. ADG-Lys showed good storage stability for 5 months, but its thermal stability was poor and it could recrystallize at 100 °C. Compared with ADG-Trp, ADG-Lys has weaker hydrogen bonding interactions and stronger hydrophobic interactions related to ADG molecules, which might cause the unusual enhancement in solubility. To our knowledge, ADG-Lys prepared in this work shows the maximum ADG content (70 wt.%) and the highest ADG solubility among the reported ADG amorphous solid dispersions and co-amorphous systems.

Amorphous solid dispersions are good candidates for improving solubility in water and the oral bioavailability of poorly water-soluble active pharmaceutical ingredients (APIs). Amorphous solids become supercooled liquids when the temperature reaches the glass transition temperature (T_g). For APIs with low melting points, T_g can be below room temperature, which makes it difficult to prepare long-term stable amorphous solids. Studies on the physicochemical properties of supercooled liquids shed light on the design of ASDs for APIs with low melting points. Racemic ibuprofen (IBU) supercooled liquid has been detected using differential scanning calorimetry and powder X-ray diffraction during the melt-quenching of IBU at a low temperature (0 °C). In this work, gram-scaled IBU supercooled liquid was prepared using the melt-quenching method, maintaining a liquid state for minutes at room temperature and for hours at 10 °C, as confirmed by visual observation. The Raman spectra, IR spectra, and UV-vis spectra results indicate that the structure of the IBU supercooled liquid is similar to that of an IBU solution instead of IBU Form I. The rate of recrystallization into Form I can be adjusted by controlling the temperature and additives, as confirmed by visual observation. Moreover, long-term stable IBU dispersions, with improved aqueous solubility, were inspired by the IBU supercooled liquid. The IBU supercooled liquid model can guide the preparation of ASDs for low melting point drugs.