Moisture Adsorption-desorption Effect on the Structure of Inclusion Complex of 6-Chloro-2-pyridylmethyl Nitrate and β-Cyclodextrin

Publisher Website
Google Scholar
Abstract
A new anti-anginal drug, 6-chloro-2-pyridylmethyl nitrate (FR46171), was found to form a complex with β-cyclodextrin (β-CyD), molecular ratio 1:1. The FR46171/β-CyD complex thus prepared showed a moisture adsorption-desorption hysteresis characteristic of hydrophilic polymers. The moisture adsorption-desorption isotherm and differential scanning calorimetry indicated that the moisture adsorbed FR46171/β-CyD complex includes 13–15 mol of water while the moisture desorbed complex includes 5 mol of water. X-ray diffraction patterns of these samples confirmed their different structures. The scanning electron photomicrographs and the surface areas (BET) suggested that the moisture adsorption-desorption hysteresis observed in FR46171/β-CyD complex can be attributed to reversible hydrogen bonding between water molecules and hydroxyl groups.