Transformations of glassy indomethacin induced by ball-milling

In this work, we investigate the effect of milling on the glassy state of the molecular glass former indomethacin. Milling of this model pharmaceutical compound was performed at room temperature. The effects of the milling intensity and duration on the physical state of the glass were investigated by X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC). Depending on the milling parameters, either we observed crystallization under milling or a modification of the physical state of the glass itself. The results are confronted with previous investigations of the effects of both the cooling rate of the melt and the physical ageing of the glass. The possibilities for milling to change the configurational state of the glassy state and the local molecular organization are discussed.