Crystal engineering of the composition of pharmaceutical phases.: Do pharmaceutical co-crystals represent a new path to improved medicines?

The evolution of crystal engineering into a form of supramolecular synthesis is discussed in the context of problems and opportunities in the pharmaceutical industry. Specifically, it has become clear that a wide array of multiple component pharmaceutical phases, so called pharmaceutical co-crystals, can be rationally designed using crystal engineering, and the strategy affords new intellectual property and enhanced properties for pharmaceutical substances.