Inclusion complex essential oil into cyclodextrins and its optimization via experimental designs: a review

The scope of this review gives an insight into the inclusion complex of essential oil (EO) using cyclodextrins (CDs), including mechanism, preparation and characterization. It also mentioned that this process was influenced by the size of the inner cavity of CDs and the chemical profile of EOs. The scope has looked forward to derivative CDs, which are further modifications of native CDs to achieve more solubility and efficiency by adding hydroxyl, sulfobutylether, and methyl groups, and by using an esterification process. Subsequently, the cyclodextrin metal organic frameworks, which correspond to native CDs connected via a metal cation, were anticipated as a biocompatible porous material demonstrating a more sustained release of EOs. Indeed, supramolecular cyclodextrins obtained through the covalent binding between cyclodextrins and cross-linked reagents led to higher water solubility, stability, and sustained release. It then moves on to combining CD with biopolymer by grafting or dual encapsulation, which was studied to modulate the profile of EO release. It then moves on experimental designs used to optimize the encapsulation efficiency to reduce the amount of CD and EO added, minimize energy and time, and optimize the medium efficacy.