**3.1 Milling method**

Ibuprofen was milled in presence of β-Cyclodextrin and then PVP at different weight ratios, physical mixtures (PM) were prepared by homogenization of pure components using ceramic mortar. Milling procedure was performed in a planetary ball mill (Pulverisette 7, Fritsch) using two milling jars (45 cm3)/7 balls (⌀ = 1 cm) in ZrO2. The rotation rate was set to 300 rpm and the ball/sample weight ratio was 82.5:1. The milling procedure was optimized for 10 h at room temperature (≈298 K) constituted by 20 min milling periods with pause periods (10 min) in order to minimize the overheating of the sample.
