Advances in Colloid and Interface Science (v.174, #C)

Many bioactive components intended for oral ingestion (pharmaceuticals and nutraceuticals) are hydrophobic molecules with low water-solubilities and high melting points, which poses considerable challenges to the formulation of oral delivery systems. Oil-in-water emulsions are often suitable vehicles for the encapsulation and delivery of this type of bioactive component. The bioactive component is usually dissolved in a carrier lipid phase by either dilution and/or heating prior to homogenization, and then the carrier lipid and water phases are homogenized to form an emulsion consisting of small oil droplets dispersed in water. The successful development of this kind of emulsion-based delivery system depends on a good understanding of the influence of crystals on the formation, stability, and properties of emulsions. This review article addresses the physicochemical phenomena associated with the encapsulation, retention, crystallization, release, and absorption of hydrophobic bioactive components within emulsions. This knowledge will be useful for the rational formulation of effective emulsion-based delivery systems for oral delivery of crystalline hydrophobic bioactive components in the food, health care, and pharmaceutical industries.Emulsion-based delivery systems can be used to encapsulate, protect and release lipophilic bioactive components that are crystalline.Display Omitted► Crystalline actives can be encapsulated in emulsion-based oral delivery systems, such as emulsions and nanoemulsions. ► Active components are dissolved in the oil phase by dilution and/or heating prior to homogenization. ► Development of delivery systems depends on understanding the influence of crystals on their formation, stability, and properties. ► This review discusses encapsulation, retention, release, and absorption of crystalline actives in emulsions.
Keywords: Emulsion; Nanoemulsion; Crystallization; Nucleation; Dissolution; Encapsulation; Partitioning; Release; Bioactivity; Nutraceuticals; Functional foods;

Modeling selected emulsions and double emulsions as memristive systems by Aleksandar M. Spasic; Jovan M. Jovanovic; Mica Jovanovic (31-49).
The recent development in basic and applied science and engineering of finely dispersed systems is presented in general, but more attention has been paid to the liquid–liquid finely dispersed systems or to the particular emulsions and double emulsions. The selected systems for theoretical and experimental research were emulsions and double emulsions that appeared in the pilot plant for extraction of uranium from wet phosphoric acid. The objective of this research was to try to provide a new or different approach to elaborate the complex phenomena that occur at developed liquid–liquid interfaces. New concepts were introduced, the first is a concept of an entity, and the corresponding classification of finely dispersed systems and the second concept consider the introduction of an almost forgotten basic electrodynamics element memristor, and the corresponding memristive systems. Based on these concepts a theory of electroviscoelasticity was proposed and experimentally corroborated using the selected representative liquid–liquid system. Also, it is shown that the droplet, and/or droplet–film structure, that is, selected emulsion and/or double emulsion may be considered as the particular example of memristive systems.Display Omitted► Concept of entities related to a new classification of finely dispersed systems. ► The electron transfer phenomena at the developed liquid–liquid interfaces. ► Concept of memristor and related memristive systems. ► A theory of electroviscoelasticity. ► Liquid–liquid contact cell for the electrical interfacial potential measurements.
Keywords: Electrohydrodynamics; Electroviscoelasticity; Nanorheology; Liquid/liquid interfaces; Finely dispersed systems; Emulsions; Double emulsions; Electrified interfaces; Memory storage processes; Memristive systems;