Emulsion-Based Delivery Systems for Bioactive Compounds

Emulsion-based delivery systems harness dispersed droplets of one immiscible liquid within another to encapsulate and transport bioactive compounds. These systems encompass a range of colloidal carriers, from nanoemulsions with droplet diameters below 200 nm to multilayer emulsions and solid lipid nanoparticles. Their design focuses on improving solubility, protecting labile actives against chemical or enzymatic degradation, controlling release kinetics and enhancing bioavailability. Key strategies include the use of food-grade emulsifiers, protein–polysaccharide conjugates, solid lipid matrices and stimuli-responsive materials. Practical applications span functional foods, nutraceuticals and pharmaceuticals, enabling targeted or sustained release in the gastrointestinal tract and beyond. Recent innovations have delivered emulsions that respond to pH, temperature or redox conditions, while high internal phase emulsions and Pickering emulsions have provided superior loading capacities and physical stability. By tuning interfacial properties and microstructure, researchers can modulate digestion profiles, enhance mucosal adhesion and achieve controlled release, thereby meeting global public health and industry demands for efficacious, safe and sustainable delivery platforms.

Research from Nature Portfolio

Recent studies have demonstrated the creation of surfactant-free lipid–polymer hybrid nanoparticles formed through Maillard conjugation of serum proteins and polysaccharides, yielding ultra-stable carriers with a multilayer architecture. These pectin-coated systems can be spray-dried and reconstituted, maintaining nanoscale integrity and offering enhanced gastrointestinal robustness. Another line of investigation has introduced lipid nanocapsules stabilised by biopolymer conjugates that exhibit improved mucoadhesion and controlled release under simulated digestive conditions, pointing to broad applicability in oral delivery of hydrophobic vitamins and phytochemicals. Emerging work also explores enzyme-triggered demulsification to achieve site-specific liberation of bioactive peptides within the small intestine.

Research from all publishers

A comprehensive review of emulsion technologies in the food sector has critically evaluated nanoemulsions, high internal phase emulsions, multilayer systems and Pickering emulsions for the encapsulation of vitamins, antioxidants and antimicrobials, highlighting strategies to enhance stability, sensory attributes and functional performance. A recent examination of plant polyphenols has underscored the utility of green nanocarriers—such as lipid-based vesicles and biopolymeric nanoparticles—to overcome poor water solubility and low oral bioavailability, with advances in pH-driven and microfluidic fabrication methods. In parallel, studies on omega-3 polyunsaturated fatty acid encapsulation have demonstrated the role of biopolymer wall materials and natural antioxidants in improving oxidative stability, with evidence for the therapeutic modulation of inflammatory and neurodegenerative pathways upon consumption of encapsulated formulations.

Emulsion-Based Delivery Systems for Bioactive Compounds publication trend

The graph below shows the total number of articles in emulsion-based delivery systems for bioactive compounds across all publications each year (not limited to Nature Index journals).

Technical terms

Emulsion: Colloidal dispersion of droplets of one immiscible liquid within another, stabilised by surfactants or solid particles.

Nanoemulsion: Emulsion with droplet sizes typically below 200 nm, offering high surface area and optical transparency.

Pickering emulsion: Emulsion stabilised by solid particles adsorbed at the interface rather than traditional surfactants.

Solid lipid nanoparticle (SLN): Carrier composed of solid lipid cores stabilised by surfactants or polymers for encapsulating lipophilic compounds.

Liposome: Vesicular structure formed by phospholipid bilayers enclosing an aqueous core, used to entrap both hydrophilic and hydrophobic actives.

Encapsulation efficiency: Proportion of bioactive compound successfully entrapped within a delivery system relative to the initial amount.

Zeta potential: Electric potential at the slipping plane of a particle, indicative of colloidal stability and propensity to aggregate.

Polydispersity index (PDI): Measure of the width of size distribution within a nanoparticle population; lower values denote uniformity.

References

1. Application of Advanced Emulsion Technology in the Food Industry: A Review and Critical Evaluation. Foods (2021).
2. Polyphenols as Plant-Based Nutraceuticals: Health Effects, Encapsulation, Nano-Delivery, and Application. Foods (2022).
3. Synthetic surfactant- and cross-linker-free preparation of highly stable lipid-polymer hybrid nanoparticles as potential oral delivery vehicles. Scientific Reports (2017).
4. Omega‐3 polyunsaturated fatty acid encapsulation system: Physical and oxidative stability, and medical applications. Food Frontiers (2022).