
Editors note: This story was originally published in @TheU.
By Paul Gabrielsen—science writer, University of Utah communications
Michael Grünwald, Ryan Looper and Rodrigo Noriega, of the University of Utah Department of Chemistry, received a $1 million grant from the W.M. Keck Foundation funding studies of currently unpredictable aspects of the process of crystallization. Accurate models of how molecules come together to form solid structures will help save time in developing new pharmaceuticals and industrial materials, since researchers will be able to bypass lengthy and expensive screening processes.
“Developing a new drug that is effective, safe and affordable is an enormously expensive and time-consuming process,” said Grünwald. “With our research on how drug molecules crystallize, we hope to really speed things up, so that new antibiotics or antivirals drugs can reach patients more quickly and cheaply.”
Predicting how molecules will form crystals is, in the researchers’ words, “extraordinarily difficult.” A crystal is an arrangement of atoms or molecules in a repeating pattern, held together by attractive forces between them. While these atoms or molecules, like Legos, could possibly be arranged in many different ways, the principles of thermodynamics suggest that they will simply arrange themselves in the crystalline structure that maximizes their favorable interactions, just like magnets arrange themselves in a pattern dictated by the magnetic forces between them. This principle works very well for many simple crystalline substances, like table salt or gold, which only have one or two types of atoms and always form the same crystal structure.
Unfortunately, it often doesn’t work that way for organic drug molecules. These molecules are made up of tens or hundreds of atoms and can produce a variety of crystal structures. Often, when developing a new drug, only one of these structures has the “Goldilocks” properties of being stable enough that the drug doesn’t degrade but unstable enough that it can dissolve in the human body. Identifying which of these different crystal structures, or polymorphs, is the right one and how to reproducibly make the right polymorph requires dedicated teams of researchers, significant experimentation and time—ultimately delaying the delivery of life-saving medicines to the patient.