Pharmaceutical Salts and Co-crystals: Retrospect and Prospects
Every new field in chemistry needs a link to an application of commercial and practical interest to sustain interest. Each such field generates a whole new set of ideas, paradigms and models. These concepts need to be tested in as wide a variety of forums as possible because their generality has to be proven. The industrial enterprise has always provided an excellent testing ground for new ideas in the chemical sciences. Many fundamental concepts took root because of an impetus from industry, the most spectacular ones being the discovery of stereochemistry by Pasteur, Haber's process for nitrogen fixation, and the birth of polymer chemistry starting with the production of synthetic rubber from isoprene. The subject of crystal engineering appeared in its modern manifestation in the late 1980s and the early 1990s. Two important branches of this subject emerged. The field of co-ordination polymers quickly found its practical application in the gas absorption properties of metal-organic framework compounds. The field of organic crystal engineering found it, a little later, in the area of pharmaceutical co-crystals and salts. The chapters in this book illustrate the tremendous growth in this area during the past decade.