Microemulsion water/oil

Reaction of A -DodecyI-3-carbamoyI Pyridinium Ion with Cyanide in Oil-Water Microemulsions... 

Graciaa A, Lachaise J, Sayous JG, Grenier P, Yiv S, Schechter RS, Wade WH (1983) The partitioning of complex surfactant mixtiu es between oil-water-microemulsion phases at high surfactant concentration. J Colloid Interface Sci 93 474-486... 

Shukla, A. Janich, M. Jahn, K. Krause, A. Kiselev, M.A. Neubert, R.H.H. Investigation of pharmaceutica oil/water microemulsions by small angle scattering. Pharmaceutical Research 2002, 19, 881-886. 

Octyidodecanol has been used in the preparation of oil/ water microemulsions investigated as the vehicle for the dermal administration of drugs having no or low skin penetration. Octyidodecanol has also been evaluated as a solvent for naproxen when applied topically. ... 

In general, when we discuss a parameter between two phases, we must define the conjugate phases. In any two-phase flow, it is obvious that both of the phases are conjugate phases. In a three-phase flow—for example, involving water, oil, and microemulsion three conjugates exist water-oil, water-microemulsion, and oil-microemulsion. There are also three interfacial tensions Owo, ctwm, and Oom. Each phase has two capillary numbers. Eor example, the oil phase has two capillary numbers (Nc)ow for the water phase displacing the oil phase and (Nc)om for the microemulsion phase displacing the oil phase. 

Binks, B.P., Meunier, J., Abillon, O. and Langevin, D. (1989) Measurement of film rigidity and interfacial tensions in several ionic surfactant-oil-water microemulsions. Langmuir, 5,415-421. 

Brime, B., Molero, G., Frutos, P. and Frutos, G. (2004) Comparative therapeutic efficacy of a novel lyophilized amphotericin B lecithin-based oil-water microemulsion and deoxycholate-amphotericin B in immunocompetent and neutropenic mice infected with Candida albicans. Eur. ]. Pharm. Sci., 22, 451-458. 

Essential oils have also been shown to be useful for the delivery and to improve the bioavailability of pharmaceuticals. Recently, a patent was granted that describes a method for increasing the bioavailability of an orally administered hydrophobic pharmaceutical compound by coadministration with an essential oil (anise, basil, bergamot, etc.) [214]. In addition, the results of an investigation were reported recently on the use of oil-water microemulsions for the transdermal absorption of nifedipine, which employed essential oils (ylang ylang oil, lavender oil, cinnamon oil) and natural materials [cineole (88), menthone (50), menthol (41)] as lipophilic skin penetration enhancers [215]. 

C. Burger-Guerrisi and C. Tondre, Conductometric study of the interaction of 1 1 electrolytes with nonionic surfactant having short polyoxyethylated chains Methanolic solutions of H- and F-alkylated surfactants and oil/water microemulsions, J. Colloid Interface Sci., 1987, 116, 100. 

Wataiai H, Ogawa K, Suzuki N (1993) Formation of fluorescent complexes of Eu(lll) and Sm(lll) with [beta]-diketones and trioctylphosphine oxide in oil-water microemulsions. Anal Chim Acta 277 73-78... 

M Trotta, MR Gasco, S Morel. Relea.se of drugs from oil-water microemulsions. J Controlled Rel ) 0 237-243. 1989. 

The reaction mechanism involves hydrolysis and polycondensation resulting in the hydrolyzed molecules with oxygen bridges. This leads to the formation of a skeleton, and hence, increases the viscosity of the sol inducing gelation. After completion of the hydrolysis reaetion, the obtained product had been collected, purified by Soxhlet extraction in cyclohexene and finally dried in a vacuum. Improvement of this process implies control of the particle morphology. The particles smaller than 10 nm with low polydispersity can be obtained [193-197] using the oil-water microemulsions as a hydrolysis medium of complex metal alkoxides. 

For AOT/oil/water microemulsion systems, the following relationship has been proposed by Fletcher etal. [101] ... 

FIG. 5 An oil/water microemulsion droplet composed of an oil core dressed with a surfactant film. When an excess phase is present (Winsor I case), the chemical potential of the oil in the fully equilibrated droplet is the same as in the excess oU phase. 

Aveyard, R., B.P. Binks, P.D.I. Fletcher. 1989. Interfacial tensions and aggregate structure in pentaethylene glycol monododecyl ether/oil/water microemulsion systems. Langmuir 5 1210-1217. 

C. Alba-Simionesco, J. Teixeira, and C.A. Angell 1989 Structural characterization of glass forming oil/water microemulsions by neutron scattering, J. Chem. Phys. 91, 395-398. 

Moreno, M. A., Frutos, R, and Ballesteros, M. P. 2001. Lyophilized lecithin based oil-water microemulsions as a new and low toxic delivery system for Amphotericin B. Pharmaceutical Research, 18, 344-351. 

Graciaa, A., Lachaise, J., Sayous, G., Grenier, P., Yiv, S., Schechter, R. S. and Wade, W. H., Partitioning of complex surfactant mixtures between oil/water/microemulsion phases at high surfactant concentrations, J. Colloid Interface ScL, 93, 474 (1983). 

The preparation and physical properties of oil/water microemulsions containing liquid paraffin, glycerol, water and blends of Tween 60 and Span 80 have been examined [180]. The decrease in micellar size as the surfactant/alcohol ratio was increased is similar to the situation observed with solubilized micellar solutions formed by non-ionic surfactants. Turbidity spectra methods of particle sizing have shown that an increase of temperature of preparation over the range 25 to 80° C led to a gradual decrease in the modal diameter and the half-width of the size distribution curve. Phase diagram studies on micellar solutions prepared at 70° C have indicated a pronounced dependence of the area of existence of microemulsions on the ratio of Tween to Span in the system and on the oil... 

None of the fluorinated surfactants was suitable for preparing oil-water microemulsions. Thoay concluded that fluorinated surfactants weaken the CH—CH interchain interaction essential for the formation of stable oil-water microemulsions. 

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