In-Depth Study of Cyclodextrin Complexation with Carotenoids toward the Formation of Enhanced Delivery Systems

The goal of this study was molecular modeling of cyclodextrin (CD) and carotenoid complex formation. Distinction was made between complexes resulting from interactions between carotenoids and either molecularly dispersed CDs or solid crystalline CDs, considering that both cases can occur depending on the complex formation process pathways. First, the formation of complexes from dispersed CD molecules was investigated considering five different CDs (alpha CD, beta CD, methyl-beta CD, hydroxypropyl-beta CD, and gamma CD) and lutein, as a model carotenoid molecule. The interactions involved and the stability of the different complexes formed were evaluated according to the CD size and steric hindrance. Second, the formation of complexes between four different crystalline CDs (beta CD with three different water contents and methyl-beta CD) and three carotenoid molecules (lutein, lycopene, and beta-carotene) was studied. The docking/adsorption of the carotenoid molecules was modeled on the different faces of the CD crystals. The findings highlight that all the CD faces, and thus their growth rates, were equally impacted by the adsorption of the carotenoids. This is due to the fact that all the CD faces are exhibiting similar chemical compositions, the three studied carotenoid molecules are rather chemically similar, and last, the water-carotenoid interactions appear to be weak compared to the CD-carotenoid interactions.

Automated summary

This study focused on molecular modeling of cyclodextrin and carotenoid complex formation, analyzing interactions between dispersed CD molecules and crystalline CDs to understand the complex formation process pathways. The results showed that different faces of CD were equally impacted by carotenoid adsorption, indicating similar chemical compositions across CD faces.