Nanoethosomal formulation of gammaoryzanol for skin-aging protection and wrinkle improvement: a histopathological study

Background: Free radical scavengers and antioxidants, with the main focus on enhanced targeting to the skin layers, can provide protection against skin ageing.

Objective: The aim of the present study was to prepare nanoethosomal formulation of gammaoryzanol (GO), a water insoluble antioxidant, for its dermal delivery to prevent skin aging.

Methods: Nanoethosomal formulation was prepared by a modified ethanol injection method and characterized by using laser light scattering, scanning electronic microscope (SEM) and X-ray diffraction (XRD) techniques. The effects of formulation parameters on nanoparticle size, encapsulation efficiency percent (EE%) and loading capacity percent (LC%) were investigated. Antioxidant activity of GO-loaded formulation was investigated in vitro using normal African green monkey kidney fibroblast cells (Vero). The effect of control and GO-loaded nanoethosomal formulation on superoxide dismutase (SOD) and malondialdehyde (MDA) content of rat skin was also probed. Furthermore, the effect of GO-loaded nanoethosomes on skin wrinkle improvement was studied by dermoscopic and histological examination on healthy humans and UV-irradiated rats, respectively.

Results: The optimized nanoethosomal formulation showed promising characteristics including narrow size distribution 0.17?±?0.02, mean diameter of 98.9?±?0.05?nm, EE% of 97.12?±?3.62%, LC% of 13.87?±?1.36% and zeta potential value of –15.1?±?0.9?mV. The XRD results confirmed uniform drug dispersion in the nanoethosomes structure. In vitro and in vivo antioxidant studies confirmed the superior antioxidant effect of GO-loaded nanoethosomal formulation compared with control groups (blank nanoethosomes and GO suspension).

Conclusions: Nanoethosomes was a promising carrier for dermal delivery of GO and consequently had superior anti-aging effect.