Thermal stability of solid dispersions of naphthalene derivatives with β-cyclodextrin and β-cyclodextrin polymers

The thermal stabilities of some naphthalene derivatives (1-naphthyl acetate, 2-acetylnaphthalene, 1-naphthol) in beta-cyclodextrin (beta-CD) inclusion complexes and in beta-CD-containing polymeric systems (Poly beta-CD) have been studied using thermal and thermogravimetric analyses and infrared spectroscopy. In beta-CD systems, the stability of the 1-naphthyl acetate complex is lower than that of the 2-acetylnaphthalene complex, and both are more stable than the corresponding physical mixtures. For Poly beta-CD systems, the solid dispersions result much more stable than the corresponding beta-CD ones, both at room temperature and at 60 degrees C. In the case of Poly beta-CD, besides the inclusion within CD cavities, the interaction of the guest with the crosslinking network confers an additional stability against volatilization. In contrast, an analogous crosslinked polymer prepared using sucrose instead of beta-CD does not retain noticeable amounts of the naphthalene derivatives. (C) 2006 Elsevier B.V. All rights reserved.