Preparation, characterization, and pharmacological application of oral Honokiol-loaded solid lipid nanoparticles for diabetic neuropathy

[Display omitted] •We formulated oral Honokiol-SLNs to enhance bioavailability and evaluated their effectiveness for DN.•Honokiol-SLNs exhibited a sustained release profile at pH 7.4, based on in- vitro release data.•In comparison to Honokiol-Pure suspension, Honokiol-SLNs showed 8-fold higher oral bioavailability.•Honokiol-SLNs initially demonstrated a neuroprotective potential against H2O2-stimulated PC12 cells.•In-vivo studies demonstrated that the use of Honokiol-SLNs significantly reduced oxidative stress. Honokiol is a phytochemical component with a variety of pharmacological properties. However, the major limitation of Honokiol is its poor solubility and low oral bioavailability. In this study, we formulated and characterized oral Honokiol-loaded solid lipid nanoparticles (SLNs) to enhance bioavailability and then evaluated their effectiveness in experimental diabetic neuropathy (DN). The finalized formulation has a spherical morphology, a particle size (PS) of 121.31 ± 9.051 nm, a polydispersity index (PDI) of 0.249 ± 0.002, a zeta potential (ZP) of −20.8 ± 2.72 mV, and an entrapment efficiency (% EE) of 88.66 ± 2.30 %. In-vitro release data shows, Honokiol-SLNs displayed a sustained release profile at pH (7.4). The oral bioavailability of Honokiol-SLNs was remarkably greater (8-fold) than Honokiol-Pure suspension. The neuroprotective property of Honokiol-SLNs was initially demonstrated against hydrogen peroxide H2O2-stimulated PC12 (pheochromocytoma) cells. Furthermore, results of in-vivo studies demonstrated that treatment with Honokiol-SLNs significantly (p