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

Abstract

The poor water solubility of prednisolone (PD) can be improved by forming inclusion complexes with β-cyclodextrin (β-CD). Here, the PD/β-CD complex with a 1:2 molar ratio was successfully prepared by the saturated solution method, and its single-crystal structure was determined for the first time. The interactions between the host and guest molecules were investigated by quantum chemical methods. The thermodynamic phase diagram of PD/β-CD was established by using the static equilibrium method. The effects of the temperature and solvent composition on the preparation process of PD/β-CD were further studied. Molecular dynamics simulations were conducted to probe the formation mechanism of PD/β-CD, thereby verifying the phase region. In addition, hydrogen bonding facilitated the inclusion of the PD molecule within the CD dimer. van der Waals forces played a crucial role in the PD/β-CD formation. This study contributes to our better understanding of the structural features and formation mechanism of inclusion complexes and offers valuable insights into the industrial production of drug inclusion complexes.

Structural Elucidation and Release Enhancement of the Florfenicol/β-Cyclodextrin Inclusion Complex

“…38 Utilizing 100 mg of each powdered sample, dissolution tests were conducted in 375 mL of distilled deionized water within vessels maintained at precise temperatures of 15, 25, and 35 °C (±0.1 °C) and a paddle rotation of 40 rpm. Aliquots of 2 mL were periodically extracted at predetermined intervals (5,10,15,20,25,30,40,50,65,80,95,110,140,170,215,260, 320, 410, 500, 620, 740, 920, 1100, 1340, and 1640 min) for HPLC analysis, with immediate replenishment by fresh buffer to preserve solution volume consistency. Each sample was filtered through a 0.22 μm PTFE syringe filter, diluted as necessary, and analyzed via HPLC-UV.…”

“…This makes producing high-purity, high-yield inclusion complex products a significantly challenging task. Ternary phase diagrams of inclusion complexes are vital tools for studying phase equilibrium, offering a thermodynamic basis for complex preparation and helping identify stable production regions. , They serve as essential guides for assessing the feasibility of crystallization processes and obtaining high-purity inclusion complex products. Additionally, the current preparation of FLO inclusion complexes often involves organic solvents , contradicting the principles of green chemistry, , thereby making the development of more environmentally friendly and efficient green preparation methods highly anticipated.…”