Development of Water-in-Oil Emulsions as Delivery Vehicles and Testing with a Natural Antimicrobial Extract

Abstract

Water-in-oil (W/O) emulsions have high potential for several industrial areas as delivery systems of hydrophilic compounds. In general, they are less studied than oil-in-water (O/W) systems, namely in what concerns the so-called fluid systems, partly due to problems of instability. In this context, this work aimed to produce stable W/O emulsions from a natural oil, sweet almond oil, to be further tested as vehicles of natural hydrophilic extracts, here exemplified with an aqueous cinnamon extract. Firstly, a base W/O emulsion using a high-water content (40/60, v/v) was developed by testing different mixtures of emulsifiers, namely Tween 80 combined with Span 80 or Span 85 at different contents. Among the tested systems, the one using a 54/46 (v/v) Span 80/Tween 80 mixture, and subjected to 12 high-pressure homogenizer (HPH) cycles, revealed to be stable up to 6 months, being chosen for the subsequent functionalization tests with cinnamon extract (1.25–5%; w/v; water-basis). The presence of cinnamon extract leaded to changes in the microstructure as well as in the stability. The antimicrobial and antioxidant analysis were evidenced, and a sustained behavior compatible with an extract distribution within the two phases, oil and water, in particular for the higher extract concentration, was observed.

CuO nanoparticles/Indonesian cedarwood essential oil‐loaded chitosan coating film: characterisation and antifungal improvement against Penicillium spp.

“…Colucci et al . (2020) explained that using the fluorescence method the dispersed phase was not clearly perceptible once it had sizes lower than 2 µm.…”

Transdermal Delivery of Therapeutic Compounds With Nanotechnological Approaches in Psoriasis

“…Unlike high-energy emulsification, low-energy emulsification is based on the physicochemical properties of components, which is prevailing when expensive or sophisticated manufacturing equipment as required for high-energy methods are unavailable ( Bernardi et al, 2011 ). The produced o/w or w/o NEs can be formulated into a variety of topical formulations, such as liquids, sprays, and creams, transporting highly hydrophilic or hydrophobic components ( Wang et al, 2007 ; Colucci et al, 2020 ).…”

Development of Polymer-Assisted Nanoparticles and Nanogels for Cancer Therapy: An Update

“…Oil-in-water emulsion consists of the oil phase being dispersed in the form of droplets into a continuous water phase, and vice versa for water-in-oil emulsion. Generally, w/o emulsion has lower stability than o/w emulsion due to water droplets' high mobility [51,52]. The formation of polymeric NPs via emulsification can be achieved either by emulsification-solvent evaporation or emulsification-solvent diffusion methods [51,53].…”