Insights into Structural Features and Ternary Phase Diagrams of Prednisolone/-Cyclodextrin Inclusion Complex

The prednisolone/& beta;-cyclodextrin complex with a 1:2molar ratio was successfully prepared, and its single-crystal structurewas determined for the first time. The thermodynamic phase diagramof this complex was established to support the preparation processby solution crystallization. Molecular dynamics simulations were conductedto probe the intermolecular interactions and the formation mechanismof prednisolone/& beta;-cyclodextrin complex. Thepoor water solubility of prednisolone (PD) can be improvedby forming inclusion complexes with & beta;-cyclodextrin (& beta;-CD).Here, the PD/& beta;-CD complex with a 1:2 molar ratio was successfullyprepared by the saturated solution method, and its single-crystalstructure was determined for the first time. The interactions betweenthe host and guest molecules were investigated by quantum chemicalmethods. The thermodynamic phase diagram of PD/& beta;-CD was establishedby using the static equilibrium method. The effects of the temperatureand solvent composition on the preparation process of PD/& beta;-CDwere further studied. Molecular dynamics simulations were conductedto probe the formation mechanism of PD/& beta;-CD, thereby verifyingthe phase region. In addition, hydrogen bonding facilitated the inclusionof the PD molecule within the CD dimer. van der Waals forces playeda crucial role in the PD/& beta;-CD formation. This study contributesto our better understanding of the structural features and formationmechanism of inclusion complexes and offers valuable insights intothe industrial production of drug inclusion complexes.