New methods for preparing cyclodextrin inclusion compounds. III. Preparation of heptakis-(2,6-di-O-methyl)-.BETA.-cyclodextrin-benzoic acid inclusion compound by sealed heating.

Abstract

The inclusion compound of heptakis-(2, 6-di-O-methyl)-β-cyclodextrin (DM β CD) and benzoic acid was prepared by heating in a sealed container. Inclusion formation was studied as a function of heating temperature, heating time, mixing molar ratio, and crystallinity of DMβ CD measured by X-ray diffractometry and infrared spectrometry. The combining molar ratio of benzoic acid to DMβ CD increased with an increase in heating temperature and time. When amorphous DMβ CD was used for the inclusion formation, the combining molar ratio of benzoic acid to DMβ CD increased to about double the amount of crystalline DMβ CD used. It was found that the heating temperature, heating time, mixing molar ratio, and crystallinity of DMβ CD affected the formation of inclusion compound.