β-Cyclodextrin  (β-CD) is a macrocyclic oligosaccharide that consists of seven glucopyranose units connected by α-(1,4) glucosidic linkage, resulting from glucopyranose units' chair conformation of cyclodextrin shaped like a cone with dual open ends, with an inner diameter of 7.8 ? and outer diameter of 15.3 ?. β-Cyclodextrin is sparingly soluble in water ; hydrogen bonding is considered the key role of cyclodextrin solubility in aqueous media. β-Cyclodextrin has a molar mass of 1135 Dalton with a calculated Log P of ?14.82 and a polar surface area value of 554.05.

β-cyclodextrin is considered a practical approach to improve water solubility, counteract curcumin degradation, and sustain curcumin release. Cyclodextrins are not toxic when taken orally as they are not absorbed in the upper GI tract and are digested by colonic bacteria. In addition, they have been classified as GRAS (Generally Recognized as Safe) substances. β-Cyclodextrin, the cyclic α(1→4) heptamer of glucose, is known to form inclusion compounds with a great variety of guests, such as derivatives of benzene , cyclohexane, adamantane , other alicyclic guests, and also inorganic molecules or ions.

Curcumin–cyclodextrin inclusion complexes can be used for pharmaceutical applications. The formation of cyclodextrin-based inclusion complexes can enhance and sustain drugs’ stability and improve their aqueous solubility. The formation of cyclodextrin-based inclusion complexes was recently proven to enhance the solubilities and thermal stabilities of difenoconazole, thiophanate, and thiram and improve the physical characteristics of environmentally safe cyclodextrinbased nanofiber pesticidal formulations.