Inclusion Complexation of Prostaglandin F_2α with α-and β-Cyclodextrins in Aqueous Solution

Abstract

The interaction of prostaglandin F_2α (PGF_2α) with α-and β-cyclodextrins in aqueous solution was investigated by potentiometric titration, solubility, and carbon 13 nuclear magnetic resonance (¹³C NMR) techniques. Changes in titration curve and solubility of PGF_2α following the binding to α-and β-cyclodextrins were quantitatively treated to obtain equilibrium constants and thermodynamic parameters. The protolytic dissociation of PGF_2α was significantly suppressed by inclusion complexation. ¹³C NMR chemical shift changes suggested that binding of PGF_2α to α-cyclodextrin was somewhat different from that to β-cyclodextrin.