Physicochemical and pharmacological characterization of α-tocopherol-loaded nano-emulsion system

The main purpose of the present study is to develop a novel nano-emulsion (NE) formulation of alpha-tocopherol (alpha-TC) with enhanced oral bloavailability and pharmacological effects Three NE formulations of alpha-TC at different loading amounts (10%, 30% and 50%) were prepared by a mechanochemical method Physicochemical properties of NE formulations were characterized with a focus on the morphology by transmission electron microscopy (TEM), droplet size distribution and zeta-potential by dynamic light scattering (DLS), and long-term stability. According to the TEM images and DLS data, mean diameters of NE droplets ranged from 80 to 400 nm, in proportion to the amount of loaded alpha-TC Although all NE formulations of alpha-TC were found to be negatively charged with the zeta-potential of ca -40 mV, NE formulations at alpha-TC content of 30% or higher exhibited severe aggregation of droplets in NE formulations during long-term storage After oral administration of 10% alpha-TC-loaded NE formulation (30 mg alpha-TC/kg) in rats, higher alpha-TC exposure was observed with a 2 6-fold Increase of bioavallability as compared to the control mixture of oil and alpha-TC. In streptozotocm-induced diabetic rats, oral administration of the alpha-TC-loaded NE formulation (30 mg alpha-TC/kg) exhibited a significant reduction of lipoperoxidant in several organs, especially the liver, however, the control mixture was less effective. With these findings, the NE approach might be efficacious to improve the oral bioavailability and anti-oxidative activities of alpha-TC (C) 2010 Elsevier B V All rights reserved