cyclodextriner

Cyclodextriner (cyclodextrins, CDs) are cyclic oligosaccharides composed of α-(1→4)-linked D-glucose units arranged in a truncated cone or torus shape. The most common natural homologues contain six (α‑CD), seven (β‑CD) or eight (γ‑CD) glucose units, producing cavities of different sizes that can host suitably sized hydrophobic guest molecules. Cyclodextrins are produced from starch by enzymatic conversion, typically using cyclodextrin glycosyltransferase.

The external surface of cyclodextrins is hydrophilic while the internal cavity is relatively hydrophobic, enabling noncovalent inclusion complexes driven by van der Waals forces, hydrophobic interactions and dehydration. This host–guest behavior can increase aqueous solubility, stability and bioavailability of poorly soluble compounds, mask odors or tastes, control release rates and reduce volatility or chemical degradation.

Applications span pharmaceuticals (formulation and drug delivery), food and beverages (flavor stabilization), cosmetics, environmental remediation, and analytical chemistry. Commonly used derivatives—such as hydroxypropyl‑β‑cyclodextrin and methylated cyclodextrins—offer improved aqueous solubility and modified complexation properties. Cyclodextrins can also be crosslinked into polymers or attached to surfaces for advanced materials and separation technologies.

Safety and regulatory status depend on the cyclodextrin type, dose and route of administration; many forms are approved for food and topical uses, while systemic and parenteral applications require specific safety evaluation. Characterization of complexes is commonly performed using techniques such as NMR, calorimetry, phase‑solubility studies and X‑ray crystallography.