Fig. 4From: Hot stage microscopy and its applications in pharmaceutical characterizationHSM micrographs of urea:4,4′-bipyridine cocrystal polymorphs at different temperatures. a Polymorph IA melts at 197 °C, b Polymorph IIB melts at 200 °C. Reprinted from Tothadi 2014 with permission from the publisherBack to article page