What Has Carbamazepine Taught Crystal Engineers?

The antiepilepsy drug carbamazepine is one of the most studied pharmaceuticals in the world. The rich story of its solid forms, cocrystals, and formulation is a microcosm of the topical world of pharmaceutical materials. Understanding carbamazepine has required time, money, and dedication from numerous researchers and pharmaceutical companies worldwide. This wealth of knowledge provides the opportunity to reflect on progress within the crystal engineering field in general. This Perspective covers the extensive solid form landscape of carbamazepine and applies these examples to discuss and answer fundamental questions in the discipline. The story encompasses screening methods, computational solid form discovery, the power and influence of crystal engineering in understanding and controlling crystals and the amorphous state, and the environmental legacy of modern pharmaceuticals. This broad but in-depth analysis of carbamazepine is a vehicle into modern crystal engineering, not only in its own right but across the spectrum of organic materials science and pharmaceutical formulation. Discoveries of carbamazepine demonstrate the potential richness in the materials chemistry of every drug.