Surfactants polysorbate

Colloidal silicon dioxide Tablet glidant Polysorbate 80 Surfactant... 

Foy, C.L., T. Takeno, Effect of polysorbate surfactants with various hydrophylic-lipophilic balance (HLB) values on leaf surface ultrastructure and mobility of methazole in plants and soil, in C.L. Foy ed). Adjuvants for Agrichemicals, 1992, pp. 169-185. 

In addition to the intentional use of organic additives, other organic constituents that are present in the water can have an important influence on particle behavior. For instance, Jarvie et al. (2009) found that Tween-coated (nonionic polysorbate surfactant) Si02 particles were stable in DI water, but coagulated and settled rapidly in a municipal wastewater. 

Low concentrations of the polysorbate surfactant series reduced absorption of isonicotinamide, insulin, procaineamide and sulphanilamide [131]. Several mechanisms for the reduction in absorption and plasma levels of these drugs were considered. Micellar interaction was ruled out as a negligible effect in these... 

Figure 7.33(a) Effect of sorbitan and polysorbate surfactants on percutaneous absorption of salicylic acid in the presence of dimethyl sulphoxide. A, 10 % sorbitan monolaurate plus 10% dimethyl sulphoxide plus 10% salicylic acid V, 10% sorbitan monopalmitate plus 10% dimethyl sulphoxide plus 10% salicylic acid , 10% sorbitan trioleate plus 10% dimethyl sulphoxide plus 10% salicylic acid , 10% polysorbate 20 plus 10% dimethyl sulphoxide plus 10 % salicylic acid A, 10 % polysorbate 40 plus 10 % dimethyl sulphoxide plus 10% salicylic acid , 10% polysorbate 60 plus 10% dimethyl sulphoxide plus 10% salicylic acid O, 10% dimethyl sulphoxide plus 10% salicylic acid and , 10% salicylic acid. 

Emulsions of fatty- and petroleum-based substances, both oils and waxes, of the o/w type are made by using blends of sorbitan fatty esters and their poly(oxyethylene) derivatives. Mixtures of poly(oxyethylene(20)) sorbitan monostearate (Polysorbate 60) and sorbitan monostearate are typical examples of blends used for lotions and creams. Both sorbitan fatty acid esters and their poly(oxyethylene) derivatives are particularly advantageous in cosmetic uses because of their very low skin irritant properties. Sorbitan fatty ester emulsifiers for w/o emulsions of mineral oil are used in hair preparations of both the lotion and cream type. Poly(oxyethylene(20)) sorbitan monolaurate is useflil in shampoo formulations (see Hairpreparations). Poly(oxyethylene) sorbitan surfactants are also used for solubilization of essential oils in the preparation of colognes and after-shave lotions. 

A multiwavelength approach might have been considered as an alternative to chemical derivatisation. Ruddle and Wilson [62] reported UV characterisation of PE extracts of three antioxidants (Topanol OC, Ionox 330 and Binox M), all with identical UV spectra and 7max = 277 nm, after reaction with nickel peroxide in alkaline ethanolic solutions, to induce marked differentiation in different solvents and allow positive identification. Nonionic surfactants of the type R0(CH2CH20) H were determined by UV spectrophotometry after derivatisation with tetrabromophenolphthalein ethyl ester potassium salt [34]. Magill and Becker [63] have described a rapid and sensitive spectrophotometric method to quantitate the peroxides present in the surfactants sorbitan monooleate and monostearate. The method, which relies on the peroxide conversion of iodide to iodine, works also for Polysorbate 60 and other surfactants and is more accurate than a titrimetric assay. 

Surfactants. The use of surfactants is greatly restricted in formulating ophthalmic solutions. The order of surfactant toxicity is anionic > cationic >> nonionic. Several nonionic surfactants are used in relatively low concentrations to aid in dispersing steroids in suspensions and to achieve or to improve solution clarity. Those principally used are the sorbitan ether esters of oleic acid (Polysorbate or Tween 20 and 80), polymers of oxyethylated octyl phenol (Tyloxapol), and polyoxyl 40 stearate. The lowest concentration possible is used to perform the desired function. Their effect on preservative efficacy and their possible binding by macromolecules must be taken into account, as well as their effect on ocular irritation. The use of surfactants as cosolvents for an ophthalmic solution of chloramphenicol has been described [271]. This com-... 

Although ionic surfactants are often associated with denaturation of proteins [104], the nonionic surfactant polysorbate 80 has been included in several marketed formulations and serves to inhibit protein aggregation. The mechanism may be the greater tendency of the surfactant molecules to align themselves at the liquid/ air interface, excluding the protein from the interface and inhibiting surface denaturation. 

CH CHzCH CH H CH CHzIgCHs Figure 7.9.5 The anionic surfactant TWEEN 20 Polysorbate 20. 

Surfactants are well-known protein denaturants. However, when sufficiently dilute, some surfactants (e.g. polysorbate) exert a stabilizing influence on some protein types. Proteins display a tendency to aggregate at interfaces (air—liquid or liquid—liquid), a process that often promotes their denaturation. Addition of surfactant reduces surface tension of aqueous solutions and often increases the solubility of proteins dissolved therein. This helps reduce the rate of protein... 

Polyfsodium styrenesulfonate), 23 368 Polysorbate 60, cosmetic surfactant, 7 834t Polysorbate 65, function as ingredient in cosmetics, 7 829t... 

Enhancers proposed for potential use for the buccal route include those studied for transdermal delivery [102], such as dimethyl sulfoxide (DMSO), dimethylformamide, ethanol, propylene glycol, 2-pyrxolidones, decylmethyl sulfoxide, azone, sodium lauryl sulfate, oleic acid, bile salts, and nonionic surfactants (polysorbates). These enhancers fall into six categories [103] ... 

Mean particle size ranges 50 to 1000 mn. Depending on the type and concentration of the lipid, 0.5 to 5% emulsifier (surfactant) has to be added for physical stabilization. For dermal use, surfactants are very often poloxamer 188, polysorbate 80, lecithin, tyloxapol, polyglycerol methylglucose distearate (Tegocare 450), sodinm cocoamphoacetate (Miranol Ultra C32), or saccharose fatty acid ester. 

Indeed, the selection of raw materials from the pharmaceutical perspective is severely restricted by toxicity concerns, and Attwood and Florence (1998) suggested that only a few nonionic surfactants such as polysorbates 80 and 20 may be suitable for oral administration, with the possibility of some phospholipids serving the same function. Since that time a small number of other nonionic surfactants (e.g., cremo-phores) have been evaluated. 

Polysorbate 80 is widely used as a nonionic surfactant in liquid pharmaceutical products such as inhalation, suspension, and nasal suspension products, due to its properties of solubilization, reduction of surface and interfacial tension, and wetting. Direct analysis of Polysorbate 80 is quite time consuming. Size-exclusion chromatography (SEC) has been reported [5] in which a mobile phase contained the surfactant at concentrations above the critical micelle concentration. Polysorbate 80 appeared as a very broad peak and coeluted with other peaks, which makes quantification in Nasonex impossible. 

Low-molecular-weight surfactants ( emulsifiers ) are important ingredients in food products. The types of surfactants most commonly studied in food colloids research are phospholipids (lecithin), mono/diglycerides (particularly glycerol monostearate), polysorbates (Tweens), sorbitan monostearate or monooleate (Spans), and sucrose esters. These small lipid-based amphiphiles can typically lower the interfacial tension to a greater extent than the macromolecular amphiphiles such as proteins and certain gums (Bos and van Vliet, 2001). 

Surfactant Prevent/control aggregation, particle formation and surface adsorption of drug Examples include polysorbate 20 and 80 Employed if aggregation during the lyophilization process is an issue May serve to reduce reconstitution times Examples include polysorbate 20 and 80... 

Another aspect of polysorbates is that they are inherently susceptible to oxidative degradation. Often, as raw materials, they contain sufficient quantities of peroxides to cause oxidation of protein residue side chains, especially methionine (59). The potential for oxidative damage arising from the addition of stabilizer emphasizes the point that the lowest effective concentrations of excipients should be used in formulations. For surfactants, the effective concentration for a given protein will depend on the mechanism of stabilization. It has been postulated that if the mechanism of surfactant stabilization is related to preventing surface-denaturation, the effective concentration will be around the detergent s critical micellar concentration. Conversely, if the mechanism of stabilization is associated with specific protein-detergent interactions, the effective surfactant concentration will be related to the protein concentration and the stoichiometry of the interaction (39). 

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