Emulsifying agents sorbitan esters

Typical commercial ethoxylated sorbitan fatty acid esters are yellow Hquids, except tristearates and the 4- and 5-mol ethylene oxide adducts which are light tan soHds. These adducts, as well as the 20-mol adducts of the triesters, are insoluble but dispersible in water. The monoester 20-mol adducts are water soluble. Ethoxylated sorbitan esters are widely used as emulsifiers, antistatic agents, softeners, fiber lubricants, and solubilizers. In combination with the unethoxylated sorbitan esters or with mono- or diglycetides, these are often used as co-emulsrfiers. The ethoxylated sorbitan esters are produced by beating sorbitan esters with ethylene oxide at 130—170°C in the presence of alkaline catalysts. 

The reaction product with monoethanolamine acts as a thickening agent [41,101] and with alcohols as an emollient [40]. Also reaction products with amino acids and oligo- or polypeptides for use in cosmetic formulations are known [43]. Sorbitan esters from ether carboxylates are described as emulsifiers or mild surfactants in cosmetic formulations [39] and alkyl ether carboxylic acid taurides as nonirritant anionic surfactants for cosmetic cleaners in particular [44]. Using unsaturated ether carboxylates it is possible to make viscous formulations based on combinations of unsaturated and saturated ether carboxylates [111]. Highly purified alkyl ether carboxylates based on alcohol ethoxylates with low free alcohol content have also been described [112]. 

Sorbitan fatty acid esters are produced by polymerization of ethylene oxide to sorbitan fatty acid esters. The resulting polyoxyethylene sorbitan esters are nonionic hydrophilic emulsifiers. They are used in bakery products as antistaling agents. They ate known as polysorbates with a number as indication of the type of fatty acid used (e.g., lauric, stearic, or oleic acid). 

Is used in textile fiber processing as an antistatic, humectant and scrooping agent. It is also used as an emulsifier for hydro-phobic glycerides and sorbitan esters in blended lubricants for fibers and yarns. 

Buffers can also be provided in parenteral formulations to ensure the required pH needed for solubility and/or stability considerations. Other excipients included in parenteral products are preservatives (e.g., benzyl alcohol, p-hydroxybenzoate esters, and phenol), antioxidants (e.g., ascorbic acid, sodium bisulfite, sodium metabisulfite, cysteine, and butyl hydroxy anisole), surfactants (e.g., polyoxyethylene sorbitan monooleate), and emulsifying agents (e.g., polysorbates). An inert gas (such as nitrogen) can also be used to enhance drug stability. Stability and solubility can also be enhanced by the addition of complexation and chelating agents such as the ethylenediaminetetraacetic acid salts. For a more detailed list of approved excipients in parenteral products, the reader should consult the monographs within the USP. 

Sorbitan esters of fatty acids Emulsifying agent, solubilizing agent, surfactant, stabilizer, suspending agent, vehicle iv... 

Sorbitan esters are widely used in cosmetics, food products, and pharmaceutical formulations as lipophilic nonionic surfactants. They are mainly used in pharmaceutical formulations as emulsifying agents in the preparation of creams, emulsions, and ointments for topical application. When used alone, sorbitan esters produce stable water-in-oil emulsions and microemulsions but are frequently used in combination with varying... 

Commercial products are mixtures of partial esters of sorbitol and its mono- and dianhydrides with oleic acid. They are generally insoluble in water and are used as water-in-oil emulsifiers and as wetting agents. The main sorbitan esters are listed in Table 6.7 together with a space-filling model of a representative component of sorbitan palmitate. 

Most conditioning products are oil-in-water emulsions requiring emulsifying agents for stability. As discussed above, fatty alcohols in combination with quats can confer stability on emulsions of this type. If necessary, other emulsifiers may also be added to improve stability [61,62], Many emulsifiers used in conditioners are nonionic, including fatty alcohols, ethoxylated fatty alcohols, ethoxylated fatty esters, and ethoxylated sorbitan fatty esters [63],... 

Crillet. [Croda Inc. Croda Chem. Ltd.] Ethoxylated sorbitan esters solubilizer, emulsifier, dispersant, wetting agent fw cosmetics, foods, household prods., agrk., me working, paints, inks, [riiar-maceuticals, textiles. 

DeSotan. [Witco/Organics] Srxbitanand ethoxylated sorbitan esters emulsifier, wetting agent, antistat, lubricant, softener. 

Emsorb . [Henkel/Emery/Cospha] Sorbitan esters or ethoxylates coupler, emulsifier, lubricant, softener, wetting agent, solubilizer for textiles, leather, cosmetics, pharmaceuticals, household goods, paper, emulsion polymerization, metal processing. 

T-Maz . [PTO/Specialty Chem.] Etbox-ylated sorbitan esters emulsifier, solubilizer, wetting agent, antistat, stabilizer, dispersant, vise, modifier, suspending i ent used in the food, cosmetic, drug, textile and metalworking industries. 

Armotan . [Akzo BV] ScHbitan esters and ethoxylated sorbitan esters wetting agent, emulsifier, solubilizer for cosmetics, pharmaceuticals, cutting oils. 

DeSonic . [Witco/Organics] Etiioxy-lated alcdiol and alkyl phenyl ethers, sorbitan and ethoxylated sorbitan esters defoamor, deteigent, emulsifier, wetting agent, dispersant for textile, paper, agric., polishes, metal cleaning, detergents. 

Drewpone . [Stepan/PVO] Edioxylated sorbitan esters food emulsifier, foam-ii agent, dough conditioner. 

The esterification of a liquid solution of sorbitol with fatty acids leads to a variety of mild tensioactive agents commonly known as sorbitan esters. Under esterification conditions and high temperature (>200°C), sorbitol undergoes an internal dehydration reaction to give a tetrahydrofuran structure (sorbitan) that is esterified by the fatty acid mainly on the primary hydroxyl group (see Figure 9.2.11). When an excess of fatty acid is used, di-esters and triesters are obtained. These sorbitan esters are commonly referred to as Span . They have low water solubility but are soluble in most cosmetic oils. They are typically used as water-in-oil (0/W) emulsifiers. 

Esters of polyols (polyalcohols) and higher fatty acids frequently are used as non-ionic emulsifying agents. The sorbitan esters of fatty acids eure well known. They are prepared by esterification of sorbitol with fatty acids at temperatures of at least 190°C, usually at 220-240°C. During the reaction, a substantial portion of the sorbitol (more them 75%)is converted into anhydro-compounds (intramolecular ethers like sorbitan and isosorbide). The products become less hydrophilic due to the foirmation of these anhydro-compounds. 

Nonionic surface active agent. Used as a 0.1% soln. in toluene for extraction-photometric detn. of SO4 Ckrnas 600 rnn, e 15000, toluene). Sorbitan esters used as emulsifying agents in pharmaceutical and cosmetic preparations. Used in foods, e.g. as emulsifier. 

Sorbitan esters of fatty acids are well known as biodegradable water-in-oil emulsifiers which are particularly mild to the skin. They are used, inter alia, as emulsifiers for pharmaceutical and cosmetic formulations, as pigment dispersants in coatings and inks and as emulsifier for mineral oils and white oils in defoamer, synthetic lubricant and metal treatment formulations. Sorbitan monolaurate is employed as an antifogging agent for synthetic resin films and sorbitan monostearate and sorbitan mononooleate as emulsifier for inverse emulsion polymerization. 

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