β-Cyclodextrin Inclusion Complex – In vitro Assessment of the Antioxidant Activity

Abstract

The formation of β-cyclodextrin (β-CD) inclusion complexes is a well-established strategy to enhance the solubility, stability, and bioavailability of poorly soluble bioactive compounds. In this study, the in vitro antioxidant potential of an inclusion complex (CPD-β-CD) formed between β-CD and 8,9-dihydroxy-2H-chromeno[2,3-d]pyrimidine-2,4(3H)-dione (CPD) was evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. The percentage of radical scavenging activity was assessed for the CPD-β-CD complex, along with standard antioxidants quercetin and nordihydroguaiaretic acid (NDGA), at concentrations of 25 μM, 50 μM, and 100 μM. Notably, the CPD-β-CD complex exhibited strong antioxidant activity, achieving 96.1% inhibition of DPPH radicals even at the lowest tested concentration (25 μM). Furthermore, the IC₅₀ value was determined to be 4.5 μM, indicating a high degree of antiradical potency. These results suggest that the encapsulation of CPD within β-cyclodextrin does not significantly diminish its antioxidant effectiveness. On the contrary, the inclusion complex retains comparable activity to the parent compound, making it a promising candidate for further development in antioxidant applications.