Biperiden Hydrochloride/& beta;-Cyclodextrins supramolecular system and its cytotoxicity against lung adenocarcinoma cells

Understanding the supramolecular structures and the host and guest interactions of supramolecular systems is crucial to corroborate the biological findings. In this sense, combining experimental and theoretical approaches has allowed to comprehend the interactions between cyclodextrins (CDs) and guest molecules. Herein, biperiden hydrochloride (BPR) was successfully included into the & beta; -cyclodextrin (& beta; CD) using freeze-drying method. The drug solubility increased in presence of & beta; CD and the thermodynamic parameters for the inclusion process determined by isothermal titration calorimetry (ITC). ITC indicated that the & beta; CD supramolecular system formed a 1:1 inclusion complex. The 2D nuclear magnetic resonance (NMR) results for the & beta; CD:BPR suggested an equilibrium between two different supramolecular complexes in solution, since cross peak correlations with to different moieties was observed. The ITC and NMR findings were corroborated by the theoretical calculations. Moreover, the inclusion complexes' cytotoxicity was tested against lung adenocarcinoma cells, demonstrating that & beta; CD:BPR supramolecular system is promising for further investigation, while free BPR demonstrated to be a non-cytotoxic agent against A549 human cells.