Synthesis of Diclofenac Acid Form

Diclofenac acid form (DIC) was obtained from hydrolysis of DICNa. For this purpose, 5 mol of DICNa (1.590 g) were dissolved in 30 mL of ultrapure water (Milli-Q, Millipore, Burlington, MA, USA) at 40 ◦C. HCl 1 M was added dropwise to the solution until no more diclofenac was precipitating. The product was filtrated and washed three times with cold deionized water and let dry at 35 ◦C for 24 h. Powder X-ray diffraction (PXRD) was used to confirm the purity of DIC.
