“…[13][14][15][16][17][18][19][20] The three principal polymorphs (e.g. the primitive monoclinic polymorph (form I), trigonal polymorph (form II) and triclinic polymorph (form III)) and dihydrate (form IV) have been well characterized by XRD, DSC, 13 C-NMR, FT-IR, and Raman spectroscopy. [21][22][23][24][25] The polymorphic content of pharmaceuticals is determined and predicted by the XRD method, but this method has relatively large errors, of around ±5%, due to the crystal orientation when the sample powder is loaded on the glass plate.…”