Solubilizers surface active agents

In addition to lowering the interfacial tension between a soil and water, a surfactant can play an equally important role by partitioning into the oily phase carrying water with it [232]. This reverse solubilization process aids hydrody-namically controlled removal mechanisms. The partitioning of surface-active agents between oil and water has been the subject of fundamental studies by Grieser and co-workers [197, 233]. 

A surfactant is a surface-active agent that is used to disperse a water-insoluble drug as a colloidal dispersion. Surfactants are used for wetting and to prevent crystal growth in a suspension. Surfactants are used quite extensively in parenteral suspensions for wetting powders and to provide acceptable syringability. They are also used in emulsions and for solubilizing steroids and fat-soluble vitamins. 

Complexation between the dissolving solute and an interactive ligand [116], or solubilization of the dissolving solute by a surface-active agent in solution [121]. Each of these phenomena tends to increase the dissolution rate. 

Uses Intermediate in the synthesis of rubber accelerators, dyes, pharmaceuticals, insecticides, bactericides, textiles, and surface-active agents solvent dehairing agent solubilizer for 2,4-D. 

To increase the usefulness of bioremediation as an effective field remedial tool, significant investments have been made towards the development of means to remove sorbed PAHs, attack sources of NAPL, and subsequently increase the aqueous solubility/bioavailability, and thus the biodegradability, of targeted compounds. To date, one of the most effective ways to accomplish these tasks involves the use of surface active agents (i.e., surfactants). A variety of synthetic surfactants have been shown effective in increasing the bioavailability of PAHs and other hydrophobic contaminants (Kile Chiou, 1989, 1990 Edwards et al., 1991 Liu et al., 1991). Although the solubilization process is not completely understood, these studies showed that a variety of ionic and nonionic surfactants could significantly increase the water solubility of monitored chemicals. 

P. H. Elworthy, T. Florence, and C. B. MacFarlane, Solubilization by Surface Active Agents and its Applications in Chemistry and the Biological Sciences Chapman and Hall, London, 1968. 

Iodophors (tamed iodine) are compounds in which surface-active agents, such as nonoxynol, act as carriers and solubilizing agents for iodine. Iodophors usually enhance the bactericidal activity of iodine and reduce its vapor pressure and odor. Further, staining is avoided and high dilution with water is possible (130—132). 

Micelles are colloidal dispersions that form spontaneously, under certain concentrations, from amphiphilic or surface-active agents (surfactants), molecules of which consist of two distinct regions with opposite afL nities toward a given solvent such as water (Torchilin, 2007). Micelles form when the concentration of these amphiphiles is above the critical micelle concentration (CMC). They consist of an inner core of assembled hydrophobic segments and an outer hydrophilic shell serving as a stabilizing interface between the hydrophobic core and the external aqueous environment. Micelles solubilize molecules of poorly soluble nonpolar pharmaceuticals within the micelle core, while polar molecules could be adsorbed on the micelle surface, and substances with intermediate polarity distributed along surfactant molecules in intermediate positions. 

Donbrow, M. and E. Azaz. 1976. Solubilization of phenolic compounds in nonionic surface-active agents. II. Cloud point and phase changes in solubilization of phenol cresols, xylenols, and benzolcOdtahid Interface Sci57 20-27. 

The presence of lipids in the GI tract stimulates gall bladder contracts and biliary and pancreatic secretions, including bile salts, phospholipids, and cholesterol. These products, along with the gastric shear movement, form a crude emulsion, which promotes the solubilization of the coadministered lipophilic drug. Exogenous surface-active agents incorporated into the formulation may further stimulate the solubilization of the lipophilic compound. 

Elworthy, P. H., Florence, A. T., Macfarlane, C. B. Solubilization by surface-active agents. London Chapman and Hall 1968... 

The physical properties of surface active agents differ from those of smaller or nonamphipathic molecules in one major aspect, namely, the abrupt changes in their properties above a critical concentration. This is illustrated in Fig. 1, in which a number of physical properties (surface tension, osmotic pressure, turbidity, solubilization, magnetic resonance, conductivity, and self-diffusion) are plotted as a function of concentration. All these properties (interfacial and bulk) show an abrupt change at a particular concentration, which is consistent with the fact that above this concentration, surface active ions or molecules in solution associate to form larger units. These association units are called micelles and the concentration at which this association phenomenon occurs is known as the critical micelle concentration (cmc). 

Bell, H. 1985. The solubilization of perfumery materials by surface active agents. Soap, Perf, Cosm. 58 263-273. 

Generally, surfactants (surface-active agents) may facilitate and accentuate the emulsifying, dispersing, spreading, wetting, solubilizing,... 

Surface active agent. A chemical compound, which when dissolved or dispersed in a liquid, is absorbed at an interface giving rise to a number of important chemical properties. The compound includes in its molecule one group that has an affinity for polar surfaces, ensuring solubilization in water, and a group that has little affinity for water. 

Elworthy, P.H. Florence, A.T. MacFarlane, C.B. Solubilization by Surface Active Agents Chapman and Hall London, 1968. 

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