This perspective highlights the need for an inclusive regulatory definition and touches upon some fundamental crystal-engineering aspects and considerations useful for the design and development of pharmaceutical co-crystals.
The formulation of poorly soluble drugs is an intractable challenge in the field of drug design, development and delivery.
Arylenediamine acceptor properties and crown ether size affect the stoichiometry and supramolecular structure of co-crystals by means of restructuring of guest–host and guest–guest contacts, changing packing enthalpies and bonding energies.
Fluorine substituents control the stoichiometry and supramolecular structure of co-crystals affecting the electron density distribution over the molecule and, thus, the strength of H-bonds and p⋯π electron interactions.
A high-throughput nanoscale co-crystallisation approach is presented, that combines automation and small scale to enable the exploration of co-crystallisation conditions, resulting in 30 new binary, ternary and quaternary co-crystals.