Determining the elusive structure of the antihistamine Levocetirizine

For pharmaceuticals, knowing the chemical composition is not enough—molecular geometry and crystal structure also play an important role in a drug's activity. By using a method based on electron diffraction, it has now been possible for a research team to determine the structure of Levocetirizine, as reported in the journal Angewandte Chemie. The advantage of this technique is that, unlike for X-ray crystallography, nanoscale crystals are sufficient.