“…[28 -32] A transition from the polymorph ε (I) to a new form ε (I ) at low temperatures was observed by Debrushchak et al [29] using X-ray diffraction and infrared spectroscopy, and by Pérez et al using nuclear quadrupolar resonance (NQR) spectroscopy. [33] The solid forms of chlorpropamide were traditionally characterized by X-ray powder diffraction, [5,15,18,19,23,24,25,27,34 -36] differential scanning calorimetry, [15,16,18,23,35,37] vibrational spectroscopy, [8,15,37 -39] and NQR. [33] From the point of view of the use of vibrational spectroscopy, Al-Saieq and Riley [34] reported the infrared absorption spectra of the five solid forms.…”