Emulsions release from

Borel, P. et al.. Carotenoids in biological emulsions solubility, surface-to-core distribution, and release from hpid droplets, J. Lipid Res., 37, 250, 1996. 

T Koizumi, W Higuchi. Analysis of data on drug release from emulsions II. Pyridine release from water-in-oil emulsions as a function of pH. J Pharm Sci 57 87, 1968. 

A well-studied example of a bioemulsifier is emulsan, a cell surface-exposed molecule that allows Acinetobacter calcoaceticus RAG-1 to attach to crude oil droplets [123]. Upon depletion of the short-chain alkanes utilised by this strain, the emulsan molecules were released from the bacterial surface, thereby allowing the cells to leave the oil droplet and to find a new substrate. Important positive side-effects of this mechanism seem to be that the remaining emulsan hydrophilises the droplet and prevents both the reattachment of A. calcoaceticus RAG-1 and the coalescence of the used oil droplet with other droplets that still contain unexploited alkanes. Bredholt et al. [124] studied the oil-emulsifying activity of Rhodococcus sp. strain 094. When exposed to inducers of crude-oil emulsification, the cells developed a strongly hydrophobic character, which was rapidly lost when crude-oil emulsification started. This indicated that the components responsible for the formation of cell-surface hydrophobi-city acted as emulsion stabilisers after release from the cells. 

Fibrous bed coalescers generally have a fixed filter element constructed of fiberglass or other material that acts to coalesce (bring together) the oil droplets and to break emulsions. The coalesced oil droplets released from the filter are readily separated downstream by gravity. Coalescence in a fibrous bed coalescer involves three steps ... 

Sustained release from disperse systems such as emulsions and suspensions can be achieved by the adsorption of appropriate mesogenic molecules at the interface. The drug substance, which forms the inner phase or is included in the dispersed phase, cannot pass the liquid ciystals at the interface easily and thus diffuses slowly into the continuous phase and from there into the organism via the site of application. This sustained drug release is especially pronounced in the case of multilamellar liquid crystals at the interface. 

Doyen. K.. Carey, M.. Linforth, R.S.T., Marin. M.,andTaylor,A.J. Volatile release from an emulsion headspace and in-mouth studies. J. Agric. Food Chem., 49(2) 804-810, 2001. 

N. Garti, A. Romano-Pariente, and A. Aserin The Effect of Additives on Release from W/O/W Emulsions. Colloid Surf. 24, 83 (1987). 

In the pharmaceutics literature, an application-triggered drug release from an O/W emulsion recipe has been reported. The application of emulsions in the pharmaceutical industry is very important, and a large number of references are found in the current literature. 

Distilled lime oils are produced by steam distillation of an oil-juice emulsion that is obtained by chopping the whole fruit. The acid present in the juice acts on the oil released from the peel and changes its characteristics. The original components are modified to form a series of new compounds. The main constituent is still limonene. 

In vitro release data of propranolol hydrochloride from the four formulations evaluated ovr a 24 h period are shown in Table 2. The decreasing rank order of drug release from these samples was observed to be as follows Methocel matrix> Avicel CL-611 matrix>PVA-gelatin matrix>emulsion base. The Methocel matrix, formulation A, exhibited the maximum release of the drug, whereas the drug released was at a minimum from the PVA-gelatin matrix, formulation... 

Protein-polysaccharide conjugates can also act as the stabilizers of multiple emulsions. Fechner et al. (2007) reported that, under acidic conditions, conjugate-containing water-in-oil-in-water emulsions were more stable to coalescence than the corresponding emulsions made with just sodium caseinate. They also observed that the extent of vitamin B]2 release from the inner aqueous phase of the conjugate-based system was significantly lower. This result could be useful for preparing double emulsions with variable release behaviour. 

As an extension of the HA film approach, Yun and coworkers [32] synthesized hyaluronan microspheres using the chemistry described above, but the synthesis was completed in emulsion in one step, yielding 5- to 20-pm microspheres. These microspheres were found to be biodegradable and released three times more pDNA when incubated with hyaluronidase in PBS (phosphate buffered saline) solution (vs enzyme-free PBS). As in the case of films, DNA release from the microspheres was dependent on the DNA loading. DNA-HA microspheres were not directly used for transfection instead, DNA obtained from release experiments was used in transfection of Chinese hamster ovary (CHO) cells using Lipofectamine. The relative levels of transfection over time had the same trend as DNA release from the DNA-HA microspheres and confirmed that released DNA is bioactive. 

To recapitulate, thioridazine release from microspheres was enhanced when NaOH was added to the emulsion prior to the solvent evaporation step. This was observed for both poly(DL-lactide) and poly(L-lactide) and also for two emulsifier systems, sodium oleate and polyvinyl alcohol. It should be pointed out that NaOH is added only to the aqueous phase of the emulsion. It is not incorporated into the microspheres by this process. 

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