Analysis of solid-state Carbon-13 NMR spectra of polymorphs (benoxaprofen and nabilone) and pseudopolymorphs (cefazolin)

The solid-state 13C-NMR spectra of the polymorphs of benoxaprofen, nabilone, and cefazolin are reported using the cross-polarization/magic-angle spinning (CP/MAS) technique. In general, the spectra of the different crystal forms are different. In favorable cases the spectra of the drug in a pharmaceutical granulation can be discerned. These results provide a preliminary indication that solid-state NMR spectroscopy is a useful technique for the investigation of drug polymorphs and drugs in their dosage forms.