“…28,29 In particular, we showed in previous papers that such behavior must be taken into account for the NMR characterization of ibuprofen and model molecules (including benzoic acid) encapsulated in MCM-41. 30,31,32,33 Indeed, due to the highly mobile behavior of the drug, the 13 C cross polarization (CP) NMR experiments on such solid samples are inefficient due to the partial averaging of heteronuclear 1 H- 13 C dipolar interaction that prevents a high efficiency of the CP process, which is routinely used in solid state NMR.…”