2.2.9. PXRD Measurement

The sample powder was placed between Mylar(R) film on sample holder of Rigaku SmartLab PXRD (Tokyo, Japan). The powder di ffraction pattern was collected from 2θ = 3◦ to 40◦ at ambient temperature at the step and scan speeds of 0.01◦ and 3◦ min−1, respectively, using a Cu-K α source at 45 kV and 200 mA. The PXRD pattern was plotted using Microsoft Excel 2003 and Origin-Pro 8.5.1 software.

### 2.2.10. Crystal Structure Analysis Using Single-Crystal X-ray Di ffraction Analysis (SCXRD)

Single-crystal X-ray di ffraction data were collected in ω-scan mode using a Rigaku R-AXIS RAPID di ffractometer (Tokyo, Japan) with a Mo K α radiation (λ = 0.71075 Å) rotating anode source. The integrated and scaled data were empirically corrected for absorption e ffects using ABSCOR. The initial structures were solved using direct methods with SHELXT and refined with SHELXL. All nonhydrogen atoms were refined anisotropically. All hydrogen atoms were found in a di fference Fourier map; however, they were placed by geometrical calculations and treated using a riding model during the refinement. Two salt cocrystals of diclofenac sodium–proline–water were found and determined successfully, which then were named NDPT (from condition I) and NDPM (from condition II).
