[On the drug molecular states dispersed in cyclodextrin matrices]

Molecular states of drug molecules in cyclodextrin solid dispersion systems have been studied. The possibility of inclusion compound formation was investigated between drug and cyclodextrin molecules by grinding, sealed heating and freeze drying. Solid state fluorescent spectroscopic measurements were made on the ground mixtures as well as infrared and photo-acoustic spectroscopies. It was found that time resolved solid state fluorescence analysis was effective to investigate the molecular states of fluorescent probe dispersed in cyclodextrins. Sealed heating of drug-cyclodextrin mixture was recognized as a new unique method for preparing cyclodextrin inclusion compound. In the case of freeze drying, the freezing conditions showed great influences on the drug dispersion states and the crystallinity of the products. The results are explained in terms of the inclusion compound formation by grinding, sealed heating and freeze drying.