Formulation of ternary genistein β-cyclodextrin inclusion complex: In vitro characterization and cytotoxicity assessment using breast cancer cell line

Genistein (GT) is a poorly water-soluble flavonoid and reported for different biological activity. The present work was designed to prepare the inclusion complex using β-Cyclodextrins (β-CDs) as complexing agent and D -α-Tocopherol polyethylene glycol 1000 succinate (TPGS) as ternary substance to enhance the solubility and in vitro activity. The inclusion complex was prepared by solvent evaporation method and characterized for different physicochemical parameters. The selected GT ternary inclusion complex was further evaluated for in vitro antioxidant and cell viability study against breast cancer cell line. The phase solubility study result data revealed significantly marked enhancement in the solubility of GT. The complexation efficiency (CE) and stability constant (Ks) of GTBIC and GTTIC2 was found to 0.31% and 0.48% as well as 419.67 M-1 and 654.98 M-1, respectively. The saturation solubility results depicted a significant (p < 0.05) enhancement in the saturation solubility (2.61 and 5.27-fold) of GT. Genistein ternary inclusion complex (GTTIC2) prepared with TPGS (0.05%, w/w) showed the maximum release pattern 96.5 ± 3.98% in 90 min. The DSC and XRD spectra showed the transformation of crystalline GT into the amorphous state after complexation. The infrared (IR) and nuclear magnetic resonance (NMR) spectra confirms the formation of inclusion complex by showing changes in the characteristic peaks. GTTIC2 formulation exhibited significantly greater in-vitro antioxidant and cell viability activity against MCF7 cell than pure GT. The improved activity can be attributed to the enhanced solubility of Genistein by effective complexation in β-CDs and TPGS.