Cyclodextrins are cyclic oligosaccharides consisting of 6, 7, or 8 glucopyranose units, usually referred to as α-, β-, or γ-cyclodextrins, respectively. These compounds have rigid doughnut-shaped structures making them natural complexing agents. The unique structures of these compounds owe their stability to intramolecular hydrogen bonding between the C2- and C3-hydroxyl groups of neighboring glucopyranose units. The molecule takes on the shape of a torus with the C2- and C3-hydroxyls located around the larger opening and the more reactive C6-hydroxyl aligned around the smaller opening. The arrangement of C6-hydroxyls opposite the hydrogen bonded C2- and C3-hydroxyls forces the oxygen bonds into close proximity within the cavity, leading to an electron rich, hydrophobic interior. The size of this hydrophobic cavity is a function of the number of glucopyranose units forming the cyclodextrin.
The solubility of natural cyclodextrins is very poor. Hydroxypropyl group β- Cyclodextrin is produced by β- Obtained by introducing hydroxypropyl groups into the molecular structure of cyclodextrin. Structurally, hydroxypropyl β- Some hydroxyl groups in cyclodextrin molecules are replaced by hydroxypropyl groups. This substitution will affect the properties of cyclodextrin molecules, including increasing their solubility and altering their interaction with other molecules.
In pharmaceutical formulations, hydroxypropyl β- Cyclodextrin is commonly used as a solvent, stabilizer, and drug carrier to help improve the solubility and bioavailability of drugs.
