Inclusion complex with cyclodextrins enhances the bioavailability of flavonoid compounds: a systematic review

Flavonoids are the polyphenolic compounds widely found in plants, which possess several pharmacological activities such as, antioxidant, antinociceptive, anti-inflammatory, antiviral, antidiabetic and anticancer effects. Meanwhile, the aqueous solubility of these flavonoid compounds were very less which limits its oral administration also decreases the bioavailability and pharmacological activities. Recently, the cyclodextrin inclusion complexation method effectively improve the solubility and bioavailability of the flavonoids. The purpose of this review was to evaluate the bioavailability enhancement of flavonoid compounds after complexation with cyclodextrins. The search terms flavonoids, pharmacokinetics, bioavailability and cyclodextrins were used to retrieve the articles from, PubMed, Scopus and Web of Science until May 2018. 272 publications were identified and 20 studies were selected finally for the discussion of this review. From the selected studies the pharmacokinetic results reveal that the bioavailability of flavonoid compounds, complexed with cyclodextrins were extensively improved when compared to uncomplexed flavonoids, including the parameters such as, area under curve (AUC) and maximum plasma concentration (C-max). The use of cyclodextrins can improve the oral bioavailability of flavonoids and it can also be a way to increase the therapeutic effects. Therefore, the incorporation of flavonoids in cyclodextrins increases the development of new pharmaceutical products for the clinical application.