Maltosyl-β-cyclodextrin mediated SupramolecularHost-Guest inclusion complex used for enhancing baicalin antioxidant activity and bioavailability

Baicalin (BCL) is a flavonoid compound with demonstrated potential therapeutic benefits, but the clinical advancements are limited mainly due to its poor aqueous solubility. A guest-host supermolecular inclusion complex of mono-6- O -α-maltosyl-β-cyclodextrin (G2-β-CD) with BCL was developed to improve the aqueous solubility of BCL. The resultant inclusion complex was characterized by DSC , FT-IR, P-XRD, 1 HNMR, 2D-ROESY and SEM analysis . Solubility test suggested that G2-β-CD markedly improved the solubility of BCL and showed A L type phase diagrams. The spectral shifts suggested that the phenyl moiety is buried deeper than the chromen moiety and protrudes from the 6-hydroxyl side of G2-β-CD. Molecular docking verified the experimental findings and supported the insertion of benzene ring of BCL into G2-β-CD cavity via hydrophobic interactions and possible hydrogen bonds . The enhanced bioavailability of the inclusion complex was reflected in earlier T max , higher C max and larger AUC 0-∞ than that of BCL after its oral administration. Taken together, these findings suggested that the solid inclusion complex BCL-G2-β-CD may serve as valuable BCL solid dosage form with good solubility and dissolution rate.