Preparation and Characterization of Holmium-2-Hydroxypropyl β-Cyclodextrin Inclusion Complex and Its Stability under Gamma Radiation

The holmium inclusion complex with 2-hydroxypropyl beta-cyclodextrin (Ho-2-HP-beta-CD) was prepared and characterized by X-ray diffraction, IR and Raman spectroscopy, and thermogravimetric analysis. The preparation process involves the reaction of a solution of Ho(NO3)(3)center dot 5H(2)O with an aqueous solution of the 2-hydroxypropyl beta-cyclodextrin (2-HP-beta-CD). The compound's stability under gamma radiation in the range from 1 to 10000 Gy was studied. Only UV spectrophotometry reveals changes in the Ho-2-HP-beta-CD inclusion complex at the highest gamma radiation dose used. The stability at low doses and high solubility make Ho-2-HP-beta-CD inclusion complex a compound of interest in the new applications of lanthanides as therapeutic and biomedical agents.