2.2.1. Preparation of Praziquantel–Clay Minerals Interaction Products

PZQ was put in contact with montmorillonite and sepiolite clay powders in 100 mL of different solvents: ethanol 99% (*v*/*v*), acetonitrile, and dichloromethane, in such way that the clay/drug ratio was 5:1 *w*/*w*. The dispersion was put into magnetic stirring for 24 h at room temperature. After 24 h, the solvent was evaporated at 40 ◦C using a rotary evaporator (Buchi® R II, Flawil, Switzerland). The solid residue was stored in a desiccator at room temperature with freshly activated silica-gel grafted with a moisture indicator of Co salt.

The interaction products obtained were: PZQ–VHSet prepared with VHS and dispersed in ethanol, PZQ–VHSac prepared with VHS and dispersed in acetonitrile, PZQ–VHSdic prepared with VHS and dispersed in dichloromethane, PZQ–SEPet prepared with SEP and dispersed in ethanol, PZQ–SEPac prepared with SEP and dispersed in acetonitrile and PZQ–SEPdic prepared with SEP and dispersed in dichloromethane.
