Calcium carbonate hybrid microcomposite for oral delivery of luteolin, a poorly water-soluble phytocompound

This study aimed to develop a β-cyclodextrin (β-CD)-stabilized calcium carbonate (CaCO₃) microcomposites to improve the oral bioavailability of luteolin, a poorly water-soluble phytocompound. Luteolin-loaded CaCO₃ microcomposites without and with β-CD (F1 and F2) were fabricated using a precipitation-based biomineralization technique and achieved an excellent loading capacity of 40.5-43.0 %. The physicochemical properties of the formulations were comprehensively characterized, and the in vitro solubility/dissolution under biologically relevant conditions and in situ intestinal absorption of luteolin were significantly enhanced by the formulations. Moreover, an in vivo pharmacokinetic study demonstrated that the formulations significantly enhanced the oral bioavailability of luteolin by 2.34-3.36-fold compared with the commercial luteolin product. To the best of our knowledge, this is the first reported data regarding the use of CaCO₃ microcomposites to improve the oral bioavailability of poorly water-soluble bioactive compounds, including luteolin, thereby broadening their potential applications in the nutraceutical and pharmaceutical fields.