Cyclodextrin Inclusion Complexes
INQUIRY
Cyclodextrins (CDs) are water-soluble, non-toxic, non-reducing cyclic oligosaccharides. The main body of CD is a ring-like structure with a hydrophobic cavity and a hydrophilic outer wall. This unique structure enables CDs to form inclusion complexes with hydrophobic guests [1], [2], as shown in Fig. 1. During the complexation with CD, guest molecules are temporarily locked in the CD cavity to be beneficially modified, which finally affects their physicochemical properties, such as solubility, dispersion, stability, bioavailability, antimicrobial activity, and toxicity. It is therefore possible to enhance the properties of some active compounds by preparing inclusion complexes with CDs, and to expand the application associated with the original CDs.
Fig. 1 Schematic illustration of the formation of an inclusion complex between a CD (host) and a guest [2].
Common Applications
With the inclusion properties of CDs, host-guest CD inclusion complexes are very useful in different fields such as pharmaceuticals, cosmetics personal care, fragrance, food, and environment protection. Here we briefly discuss the uses of CD inclusion complexes in pharmaceuticals, cosmetics and fragrance encapsulation.
- Application in pharmaceuticals
As a result of being encapsulated in CDs, drug molecules are more water-soluble and stable, thereby providing better bioavailability. For example, the low water soluble anticancer drug candidate, Pt(IV)-bis(benzoato), was encapsulated in β-CD to enhance water solubility. By encapsulating the antibacterial drug chloramphenicol within the cavity of CD, the inclusion complex improved its solubility while maintaining its microbial activity, and reduced the production of reactive oxygen species (ROS) in leukocytes induced by the drug. What's more, CDs can also be used for controlled release of drugs, such as ciprofloxacin, and vancomycin [3].
CD can be used in the field of cosmetics as a transport medium in the form of inclusion complex. It encloses the active ingredients required for cosmetics in the cavity and maintains the original shape, size and characteristics of the molecules. CD can also effectively prevent the active ingredients from being oxidized, photolyzed and thermally decomposed, making them more stable and durable. Therefore, CD inclusion complexes as cosmetic formulas have been widely used in various products such as skin creams, lotions, shampoos, and toothpastes to enhance the efficacy of cosmetics in whitening, anti-aging, moisturizing, acne removal, and sterilization.
- Application in fragrance encapsulation
Most fragrances are volatile compounds, which require encapsulation for handling and industrial processing due to their poor chemical stability. CDs and fragrance ingredients can form stable inclusion complexes that remain stable for a long time even when exposed to heat, light and air. Taking menthol as an example, after complexation with β-CD, it not only effectively protects the stability of menthol, but also increases the release rate of menthol in the inclusion compound as the temperature increases. In addition, flavor chemicals such as vanillin, citral and ionone are also used to form CD inclusion complexes, which are widely used in food flavors and fragrances.
Alfa Chemistry is one of the leading CD manufacturers. In addition to kilograms of native CDs and CD derivatives, we also offer high-quality CD inclusion complexes, including CP16171-beta-CD, azelaic acid-hydroxypropyl-beta-CD, salicylic acid-CD-complex, menthol-CD-complex and vanillin-CD-complex, along with related support to meet customers' needs. We also offer custom services for other CD inclusion complexes, committed to providing the best possible experience for our customers. For more information, please feel free to contact us.
References
- Zhou, J.; et al. Cyclodextrin inclusion complexes and their application in food safety analysis: recent developments and future prospects. Foods. 2022, 11(23): 3871.
- Kfoury, M.; et al. Characterization of cyclodextrin/volatile inclusion complexes: a review. Molecules. 2018, 23(5): 1204.
- Cheirsilp, B.; Rakmai, J. Inclusion complex formation of cyclodextrin with its guest and their applications. Biol Eng Med. 2016, 2(1): 1-6.
It should be noted that our our products and services are for research use only, not for clinical use.
