“…A number of techniques have been used to test the crystal forms of medicines, such as X-ray diffraction (XRD), 7,8 Infrared (IR), 9,10 Raman, 10,11 circular dichroism 12 spectra, differential scanning calorimetry (DSC), 13 thermogravimetric analysis (TGA), 14 differential thermal analysis (DTA), 15 solid-state nuclear magnetic resonance, 16 magnetic anisotropy, 17 dilatometer and polarizing microscope. 18 However, each individual technique has its own limitation 19 and usually need two or more techniques combined to study the crystalline states of hydrates.…”