Detecting crystallization of norfloxacin in paper tablets after wet granulation by terahertz time-domain spectroscopy

Granulated and non-granulated smartFilm tablets loaded with norfloxacin (NOR) were investigated using terahertz (THz) time-domain spectroscopy (TDS) and x-ray powder diffraction (XRD). THz TDS was more sensitive to crystalline NOR, as through THz TDS, partial crystallization of NOR after wet granulation can be observed, which was not detectable by XRD. The results obtained by THz TDS were used for quantitative crystallinity assessment in the smartFilm tablets.