Natural Antioxidant-Loaded Nanoemulsions for Sun Protection Enhancement

Abstract

The aim of this study was to formulate nanodispersions to encapsulate antioxidants extracted from olive mill wastewater (OMW) and phycocyanin extracted from Spirulina maxima to act as enhancers for the skin’s protection against UV radiation. For this purpose, two water-in-oil nanoemulsions were prepared using a low-energy homogenization method. Both systems were based on isopropyl myristate as the continuous phase, while water or a mixture of glycerol and water was used as the dispersed phase. Then, antioxidants extracted from OMW and phycocyanin from Spirulina maxima were encapsulated in the water core of the nanoemulsions. The empty and antioxidant-loaded systems were then structurally studied using dynamic light scattering for the detection of their droplet size and stability over time. Electron paramagnetic resonance (EPR) spectroscopy using adequate probes was applied for the characterization of the surfactants’ monolayer in the presence and absence of antioxidants. It was found that the mean droplet diameter of the emulsions was 200 nm. The nanoemulsions remained stable for over 2 months. The encapsulated antioxidants were assessed for their scavenging activity of a model stable radical by applying EPR spectroscopy. It was found that the loaded systems exhibited an increased antioxidant capacity compared with the empty ones. Finally, the most stable system was added to commercial sunscreen lotions and the overall sun protection factor (SPF) was assessed. The sunscreen lotions that contained the nanoemulsions loaded with OMW extracts or phycocyanin showed an increase in their SPF value.

Nanotechnology for Effective Epilation: Assessment of the Application of a Protease-Containing Microemulsion

“…In recent years, nano-dispersions such as nanoemulsions or microemulsions have been increasingly used in advanced cosmetics from sun-screens to insect repellents due to their ability to offer increased stability and the superior delivery of active ingredients compared to traditional macroemulsions [11,12]. More specifically, microemulsions are thermodynamically stable liquid mixtures containing oil, water, and amphiphilic molecules that serve as the interfacial area between the two immiscible phases [13][14][15][16][17].…”

Exploring the Use of Hydroxytyrosol and Some of Its Esters in Food-Grade Nanoemulsions: Establishing Connection between Structure and Efficiency

“…We have chosen nanoemulsions as an experimental platform in our studies because nanoemulsions constitute an advanced mode of drug delivery system that has been developed to overcome the major drawbacks associated with conventional drug delivery [18,[39][40][41][42][43][44]. Because the food industry is now introducing omega-3 FA to prepare various kinds of functional foods in an attempt to provide health benefits over and above their basic nutritional aspects [45,46], there are considerable challenges in incorporating both antioxidants and omega-3 FAs into many types of functional food products due to their low watersolubility, poor chemical stability, and variable bioavailability [47].…”