*2.9. X-ray Powder Di*ff*raction*

The solid state of the drug in the samples was investigated by X-ray powder diffraction (XRPD) with a Rigaku SmartLab diffractometer equipped with a 9 kW rotating anode and a HyPix-3000 detector (Rigaku Corporation, Tokyo, Japan). Bragg–Brentano optics were set as follows: 5.0 degree (deg) incident parallel Soller slit, 1/8 mm incident slit, 10 mm length limiting slit on the incident arm of the goniometer and 4 mm receiving slit #1, open parallel slit analyzer, 5.0 degree receiving parallel Soller slit, and 13 mm receiving slit #2 on the receiving arm of the goniometer.

The samples were exposed to X-rays of Cu wavelength (1.541 Å) and measured in 1D detection mode in a θ/2θ range of 2–60 degree with a step size of 0.01 deg and a 1 deg/min scanning speed.
