Delivery of Magnolia Bark Extract in Nanoemulsions Formed by High and Low Energy Methods Improves the Bioavailability of Honokiol and Magnolol

Abstract

Honokiol (HK) and Magnolol (MG), isomers found in Magnolia officinalis bark extract (MBE), possess bioactive properties attributed to their biphenolic structure. However, their low polarity results in poor oral absorption, limiting their bioavailability. To enhance their systemic absorption after passing through the digestive tract, efficient carrier systems are essential. Nanoemulsions (NE) have been suggested to enhance their solubility in the oily core and enable passive diffusion through absorptive cells. Surfactants ensure stability by reducing surface tension between hydrophobic and hydrophilic compounds. In this study we report the preparation of NE containing HK and MG using high and low-energy methods (SNEDDS); we aimed to improve their absorption after oral administration. Results demonstrated that NE enhanced their bioavailability significantly. Compared to the free forms, HK bioavailability increased by 3.47 times, and MG by 3.03 times. SNEDDS further increased HK bioavailability by 3.98 times and MG by 7.97 times compared to their free forms.

Keywords: *Honokiol*Magnolol*Nanoemulsions*SNEDDS*Oral bioavailability