Essential oil–cyclodextrin complexes: an updated review

Abstract

Cyclodextrins, degradation product of carbohydrates, have been extensively exploited by food, pharmaceutical and cosmetic industry by virtue of their ease of availability and their ability to entrap guest moieties. Various cyclodextrin derivatives have been granted generally recognized as safe (GRAS) status by several countries. The most noteworthy characteristic of cyclodextrins is their ability to form inclusion complexes with variety of molecules, imparting protection and enabling solubility, bioavailability and safety enhancement of challenging bioactives. In the last few decades, investigations have revealed anti-microbial, anti-inflammatory, insecticidal, analgesic and sedative properties of essential oils. However, their poor solubility, volatility and sensitivity to environmental factors pose challenge for the formulation scientists. Inclusion complexes of essential oils with cyclodextrins have proved a useful strategy to circumvent these challenges. The success of this approach for essential oils is examplified by the commercial garlic oil/β-cyclodextrin products, available under the trade names Xund, Tegra, Allidex and Garlessence. Here, we present an in-depth account of essential oil loaded cyclodextrin inclusion complexes.