Nanoemulsions for delivery of flavonoids: formulation and in vitro release of rutin as model drug.

The aim of the present study is to design and characterize a rutin-loaded nanoemulsion (RT-NE) and determine the release profile of the drug in vitro. RT-NE was prepared by a high pressure homogenization technique. The obtained droplets were analyzed by optical microscopy and were shown to be of spherical shape. By dynamic light scattering, characterization of RT-NE showed an average diameter of 127 nm, polydispersity index of 0.168 and zeta potential values near neutrality (-3.49 mV). Encapsulation efficiency was of ∼82% (82.3 ± 1.62%). Drug release was characterized by an initial burst which decreased over the time, showing a sustained release profile. After 24 h, rutin released from NE reached nearly 65%. The developed system proved to be stable and suitable to encapsulating poorly water-soluble drugs.