New multicomponent solid forms of the nutraceutical pterostilbene have been discovered and characterized through experimental cocrystal screening. Among the coformers tested, picolinic acid formed a cocrystal with a 10-fold enhancement of oral bioavailability in rats, which converts the new cocrystal into a very promising candidate for new formulations of pterostilbene with improved performance.

A new cocrystal of the essential nutrient ubiquinol that is highly resistant to air oxidation has been designed and discovered in a cocrystal screening. Hydroxybenzoic acids and phenols have been selected as the coformers with the aim to transfer their molecular antioxidant properties to the cocrystal and protect ubiquinol from oxidation. The new cocrystal ubiquinol/3,4-dihydroxybenzoic acid shows a remarkably high stability under standard stress conditions, which offers alternative strategies of formulation for an important industrial problem.

In this work, we demonstrate that the centrosymmetric eight-membered supramolecular ring R2 2 (8) that is formed upon dimerization of benzoic acids has a marked tendency to establish π−hole interactions with electron-rich atoms. We have used the Cambridge Structural Database to demonstrate the preference of carboxylic acid dimers to form donor−acceptor interactions involving π−holes located at the C atoms above and below the molecular plane. Moreover, we have carried out DFT calculations (PBE0-D3/def2-TZVP) to investigate the geometric and energetic features of these interactions and how they are affected by the substituents of the aromatic ring. Finally, as an example we report the synthesis and X-ray characterization of a solvate of gallic acid with dioxane, where two molecules of dioxane are located above and below the eight-membered supramolecular ring, forming two symmetrically equivalent O•••C π−hole interactions.

A new cocrystal of Vitamin D3 (Cholecalciferol) and resorcinol has been discovered and characterized through experimental cocrystal screening. Its high stability has been studied against light, heat, and chemicals present in animal food premixes in order to develop a novel and alternative formulation to current microencapsulation approaches to protect Vitamin D3 from oxidation. Our results show that the new cocrystal is extremely stable and it can become the basis for very efficient formulations of Vitamin D3 which fulfills the stability requirements of industrial applications.

The polymorphic landscape of the nutraceutical pterostilbene has been analyzed by solving the crystal structure of forms II and III from PXRD data. Polarization effects in the previously know form I crystal structure have been observed and the structural features of the most stable high Z′ polymorph have been discussed in relation to the relative stability between the polymorphs of this important natural product.