Specific binding capacity of β-cyclodextrin with cis and trans enalapril: Physicochemical characterization and structural studies by molecular modeling

Abstract

The main objective of this work was to study an inclusion complex between enalapril (ENA), and B-cyclodextrin (B-CD). From nuclear magnetic resonance (NMR) we determined that the complex showed a 1:1 stoichiometry, with an apparent formation constant (KC) of 439 and 290 M1 for the cis and trans isomers, respectively. The molecular modeling and NMR techniques demonstrated that the aromatic moiety of ENA was inserted into the hydrophobic cavity of B-CD. When studying the chemical stability of ENA complexed to B-CD, a clear stabilizing effect was observed in both the aqueous solution and solid state.