Adsorption of Natural Essential Oils on Phyllosilicate and Cyclodextrin Surfaces by Molecular Modeling for Predicting Drug Delivery Systems

Abstract

Essential oils (EO) have been used for skin treatments for centuries due to their wide range of beneficial pharmacological properties. Their adsorption in solids with confined spaces can be an excellent support for their slow delivery. Geraniol and linalool are octadienol isomers, often found in many natural EO. Both possess interesting therapeutic properties that can be optimized for protecting them from degradation using adsorption systems and controlled delivery. Cyclodextrins (CDs) and natural clay minerals are excellent materials to serve as hosts for drugs. In this work we investigate the adsorption and desorption of these essential oil components with both hosts, β-CD and montmorillonite (MNT). Molecular modeling studies were conducted using the INTERFACE force field (FF), yielding promising results, by reproducing the experimental crystal lattice cell parameters of the β-CD-geraniol and β-CD-linalool crystallized complexes within 5%, thereby validating this FF. The adsorption of these drugs onto β-CD rings is energetically more favorable than into MNT at low EO concentrations. However, the delivery of these drugs is more favorable from the clay mineral than from β-CD. At high EO concentrations, intercalation into MNT is energetically favorable. The behavior of both isomers is similar. Surprisingly the intercalation of β-CD-geraniol and β-CD-linalool into MNT is energetically favorable, predicting a complex and hybrid composite for intercalation. These natural composites can be suitable as additives in therapeutic skin treatments.