Reviewing the manifold aspects of Ganciclovir crystal forms

Ganciclovir, an active pharmaceutical ingredient against cytomegalovirus, is known to crystallize in the form of anhydrous or hydrated phases. The crystal and molecular structures of two hydrated forms, the hydrochloride salt, and two pro-drug derivatives (i.e., the tri-N(2),O,O-acetyl and di-O-acetyl) have been successfully unveiled from powder X-ray diffraction (PXRD) or single-crystal X-ray diffraction studies. The thermal behavior of the hydrates has been unraveled by juxtaposing the results of our thermal analysis and variable-temperature PXRD experiments to those previously reported on the topic. On the whole, this investigation revisits and complements the somehow incomplete and scattered information present in the literature. It is envisaged that this study can open the way to systematic PXRD qualitative and quantitative analysis of ganciclovir mixtures formed during synthesis, isolation, or processing.