Vibrational spectroscopic analysis of theophylline in a pharmaceutical granulation process using near-, mid- and far-infrared/terahertz spectroscopy

Vibrational spectroscopic analysis of theophylline in a wet granulation process was performed. An anhydride was converted to a monohydrate during the granulation and a dehydration of monohydrate progressed during the drying process. A C-N stretching would be affected by an interaction between theophylline and a binder under a wet granulation process.