RESUMO
In order to search for new approaches to treat glioma, intranasal administration has been proposed as an alternative route to deliver drugs into the brain. Among the drug alternatives, kaempferol (KPF) has been reported to induce glioma cell death. This study aimed to prepare nanoemulsions containing KPF with and without chitosan to investigate their potential for brain delivery following intranasal administration, and to evaluate their antitumor activity against glioma cells. KPF-loaded nanoemulsion (KPF-NE) and KPF-loaded mucoadhesive nanoemulsion (KPF-MNE) were prepared by high-pressure homogenization technique and were characterized for their globule size, zeta potential, drug content, pH, viscosity, mucoadhesive strength and morphology. KPF from KPF-MNE showed significantly higher permeation across the mucosa in ex vivo diffusion studies. Histopathological examination suggests both nanoemulsions to be safe for the nasal mucosa and able to preserve KPF antioxidant capability. KPF-MNE enhanced significantly the amount of drug into rat's brain following intranasal administration (5- and 4.5-fold higher than free drug and KPF-NE, respectively). In addition, KPF-MNE reduced C6 glioma cell viability through induction of apoptosis to a greater extent than either free KPF or KPF-NE. The mucoadhesive nanoemulsion developed for intranasal administration may be a promising system for delivery to the brain, and KPF-MNE is a candidate for further antiglioma trials.