Crystal Structure of Ritonavir Form IV
The crystal structure of Ritonavir Form IV is reported. The structure was determined by electron diffraction, and the molecular conformation and hydrogen bonding show similarities to those of Forms I and III. Form II is shown to be the most thermodynamically stable of the four known polymorphs. Polymorphism means a solid material can form different […]
Ritonavir Form III
Ritonavir Form III: Lightning strikes twice at the same time, 137 miles apart Abstract Polymorph screening is a crucial step in the characterization and development of pharmaceuticals. The 1998 recall of ritonavir upon the unexpected appearance of the more stable Form II polymorph remains a notorious case of disappearing polymorphs as the presence of Form […]