Enhanced dissolution and oral bioavailability of baicalein by cocrystallization

Baicalein(BE), a natural flavonoid mainly extracted from Radix Scutellaria, has comprehensive pharmacological actions such as anti-inflammation, anti-virus and anti-cancer activities. It belongs to BCS class II compound with relatively low oral bioavailability. The current study aims to improve its aqueous solubility and dissolution and hence to enhance its oral absorption by cocrystallization technique. Slurry crystallization method was employed to prepare baicalein cocrystal with co-former caffeine(CA), followed by physicochemical characterizations with DSC, XRPD and FTIR. Compared to BE and physical mixture of BE and CA, BE-CA cocrystal had a significantly higher dissolution of BE. In addition, in comparison to BE, this cocrystal achieved reduced time to peak(t_max)as well as significantly higher peak plasma concentrations(c_max)and area under the curve(AUCs)for both BE and its active metabolite baicalin(BI)in rats, suggesting enhanced the oral bioavailability of BE.