Development of a Chitosan-based Nanoparticle Formulation for Ophthalmic Delivery of Honokiol

Retinal neovascularization (NV) is the leading cause of blindness in the majority of ocular diseases. Several treatment approaches have been developed for retinal NV; of these methods, instillation of nanoparticles into the conjunctival sac has shown potential for retinal NV treatment because it does not cause physical damage and is easy to operate.

In this study, honokiol-loaded chitosan/sulfobutylether-β-cyclodextrin nanoparticles (HKCS- NPs) were prepared for ophthalmic drug delivery systems. An inclusion complex of honokiol and sulfobutylether-β-cyclodextrin was used to incorporated insoluble honokiol into chitosan nanoparticles, which were prepared through ionotropic gelation.

HK-CS-NPs featured a spherical surface with a narrow size distribution of polydispersity index less than 0.250, a mean size range of 373-523 nm, a positive surface charge of +19.9 to +24.2 mV, and an entrapment efficiency of 84.92%. In vitro release studies showed an initial burst release phase and a sustained release phase of nanoparticles. Moreover, in vivo study showed that HK-CS-NPs exhibited good ocular tolerability and could improve ophthalmic bioavailability of honokiol. In particular, the maximum concentration of honokiol after administration of HK-CS-NPs was enhanced by 1.65 times compared with that after instillation of the honokiol suspension alone.

This study proposes HK-CS-NPs as a potential ophthalmic delivery system.