Impact of mesoporous silica on the chemical degradation of Praziquantel upon grinding

Praziquantel and Syloid 244 FP (amorphous silicon dioxide) were ground in a vibrational mill in standard conditions ($15^{\prime}$ or $30^{\prime}$ at 25 Hz). Amorphous solid dispersions were obtained in a very short grinding time (15 min), as testified by DSC, PXRD and ESEM analyses. Samples ground at $15^{\prime}$ and $30^{\prime}$ showed the presence of the same degradation product, as was evident from UPLC, MS and NMR analyses. This short paper brings to light the tremendous lattice de-structuration ability of Syloid 244 FP upon grinding toward Praziquantel as well as its detrimental influence on promoting chemical degradation through ring opening and oxidation.