Cocrystal systems of pharmaceutical interest: 2009

As scientists become more aware of a substantial expansion in the scope of solid-state structural variations that can be obtained through the cocrystallization of several molecules in a single lattice structure, studies of the mixed molecular crystal systems known as cocrystals have mushroomed. Along these lines, workers have researched the assembly of supramolecular synthons and crystal engineering in ever-increasing efforts to produce materials having new and useful properties. For the purposes of this review, cocrystal systems will be regarded as those mixed crystal systems where the individual components exist as solids under ambient conditions. Particularly useful guidance has been provided by Aakeröy, where cocrystal formation from supramolecular synthons is to be considered as forming from discrete neutral molecular species that are solids at ambient temperatures, and where the cocrystal is a structurally homogeneous crystalline material that contains the building blocks in definite stoichiometric amounts.