What are multiple emulsions?
What are multiple emulsions?
Multiple emulsions are complex polydispersed systems where both oil in water and water in oil emulsion exists simultaneously which are stabilized by lipophillic and hydrophilic surfactants respectively. The ratio of these surfactants is important in achieving stable multiple emulsions.
What is the Schulman and Cockbain theory?
Eccleston, 1992] According to Schulman and Cockbain theory, it was revealed that molecular interactions arising at a “nujol” (oil-droplet)/ water interface were correlated with the molecular interactions at an air/water interface which had been investigated by Schulman and Rideal in 1937.
What is emulsion classification?
Emulsions are classified as- Oil in water type- The emulsion in which oil is present as the dispersed phase and water as the dispersion medium (continuous phase) is called an oil-in-water emulsion.
What is microemulsion Slideshare?
Microemulsion is an isotropic mixture of oil, surfactant, Cosurfactant and drug. Upon mild agitation followed by dilution in aqueous media, such as gastrointestinal (GI) fluids, the systems can form fine oil in water (O/W) Microemulsions which usually have a droplet size less than 100 nm.
What are two types of emulsions?
There are two basic types of emulsions: oil-in-water (O/W) and water-in-oil (W/O). These emulsions are exactly what they sound like, as pictured below. In every emulsion there is a continuous phase that suspends the droplets of the other element which is called the dispersed phase.
What is biphasic system explain emulsion in detail?
Emulsions are biphasic liquid systems consisting of two immiscible liquid phases. These phases are present in such as way that one phase is dispersed in the other continuous phase. Examples of emulsions include mayonnaise, milk, lotions, etc.
What is pharmaceutical emulsion?
Pharmaceutical emulsions are liquid disperse systems in which the dispersed phase is composed of small globules of a liquid distributed throughout a vehicle in which it is immiscible. Pharmaceutical emulsions are used for the administration of nutrients, drugs, and diagnostic agents.
Multiple emulsions are complex polydispersed systems where both oil in water and water in oil emulsion exists simultaneously which are stabilized by lipophillic and hydrophilic surfactants respectively. The ratio of these surfactants is important in achieving stable multiple emulsions.
What causes the instability of double emulsions?
Three possible mechanisms are responsible for the physical instability of double emulsions: droplet coalescence, Oswald ripening, diffusion to the outer continuous phase, and droplet escape (or coalescence between the inner dispersed phase and external continuous phase) (see Aserin (2008), Pays et al. (2001), Klahn et al. (2002) ).
Why is the ratio of surfactants important in achieving multiple emulsions?
The ratio of these surfactants is important in achieving stable multiple emulsions. Among water-in-oil-in-water (w/o/w) and oil-in-water-in-oil (o/w/o) type multiple emulsions, the former has wider areas of application and hence are studied in great detail.
What do we know about the stability and release profiles of emulsions?
In vitro studies were performed to investigate the stability and release profiles of these systems. Multiple emulsions showed great stability and the best ability to carry and release ferulic acid. In vivo evaluations highlighted their best capability to treat UV-B-induced erythema.
