Enhanced Oral Bioavailability of Isoformononetin Through Nanoemulsion: Development, Optimization, and Characterization

Isoformononetin (IFN) is a methoxyl derivative of daidzein and has been stated as a potent osteogenic isoflavone. However, IFN has low oral bioavailability. Advancement in the technology has led to the development of newer drug carrier systems, featuring the delivery of drugs with low oral bioavailability to advance their clinical application.

The IFN nanoemulsion (IFN-NE) was developed and optimized using the design of the experiment tool and technique approaches.

The optimized IFN-NE has a particle size of 174.65 ± 1.63 nm, PDI of 0.244 ± 0.004, and zeta potential of − 30.69 ± 4.99 mV, respectively. The TEM images of optimized IFN-NE showed the spherical globular size of the nanoemulsion. The entrapment efficiency showed higher entrapment of IFN in the NE (96.04 ± 1.28%). The compatibility of IFN with excipients was confirmed by physical state characterization such as FTIR and DSC, illustrating no interaction. Optimized IFN-NE formulation was stable at different temperature conditions. In comparison to a free drug suspension, IFN-NE showed sustained drug release over a 24-h period of time. Additionally, in situ, single-pass intestinal perfusion (SPIP) results displayed significant enhancement of IFN permeability through the intestine of rats from IFN-NE when compared to free IFN.

Pharmacokinetics results revealed the enhanced relative oral bioavailability of IFN-NE compared to IFN suspension using female Sprague–Dawley (SD) rats as animal models. The developed IFN-NE can be a promising candidate to overcome the low oral bioavailability of IFN.