Recent progress in oil-in-water-in-oil (O/W/O) double emulsions

Abstract

Oil-in-water-in-oil (O/w/O) double emulsions are recognized as an advanced design route for oil structuring that shows promising applications in the pharmaceutical, cosmetic, and food fields. This review summarizes the main research advances of O/w/O double emulsions over the past two decades. it mainly focuses on understanding the preparation strategies, stabilization mechanism, and potential applications of O/w/O double emulsions. Several emulsification strategies are discussed, including traditional two-step emulsification method, phase-inversion approach, membrane emulsification, and microfluidic emulsification. Further, the role of interfacial stabilizers and viscosity in the stability of O/w/O double emulsions will be discussed with a focus on synthetic emulsifiers, natural biopolymer sand solid particles for achieving this purpose. Additionally, analytical methods for evaluating the stability of O/w/O double emulsions, such as advanced microscopy, rheology, and labeling assay are reviewed taking into account potential limitations of these characterization techniques. Moreover, possible innovative food applications are highlighted, such as simulating fat substitutes to decrease the trans-or saturated fatty acid content and developing novel delivery and encapsulation systems. This review paves a solid way for the exploration of O/w/O double emulsions toward large-scale implementation within the food industry.

Moisturizer in Patients with Inflammatory Skin Diseases

“…Long-chain fatty acids, such as palmitic acid and stearic acid, are commonly used. In particular, stearic acids are widely used in cosmetics as emollients and emulsifiers because they are saturated fatty acids, liquid, and chemically or microbially stable [ 31 ]. Alcohols used in cosmetics include cetyl alcohol and stearyl alcohol, which are also used in creams or emulsions as emulsifiers, as well as softening agents.…”

Numerical Investigation of Double Emulsion Droplets using Modified Flow Focusing Microfluidic Device for Drug Delivery

“…Brackbill's continuum surface force (CSF) model is used to obtain the interfacial surface force term (F ϒ ) at the free surface according to the combined volume fraction [23] as represented in Eq. (7). Moreover, the considered variables presented in the interfacial surface force term are available in Eq.…”

“…Microfluidics is able to control fluid flow precisely in the microchannel that usually presents in multiphase flow [1]. This technology has been successfully implemented in several fields as follows: lab on a chip [2], drug delivery [3], bio-medical [4], digital polymerase chain reaction (ddPCR) procedure [5], cell sorting [6], food industry [7] and chemical [8]. Although microfluidics plays an essential role in many sectors, the current development of this technology focuses on drug delivery since the world has been impinged by the Covid-19 pandemic for the last two years.…”

Mannose-based surfactant as biofunctional nanoemulsion stabilizer

“…A wide range of emulsification methods can be used to produce different types of emulsions, including oilin-water (O/W), water-in-oil (W/O), or even more complex multiple emulsions, e.g. oil-in-water-in oil (O/W/O) and water-in-oil-in-water (W/O/W) systems [5][6][7]. Extreme emulsification, phase inversion, nanofluidics, membrane emulsification or satellite droplets are only a few of the most extended methods used in their preparation [8].…”