Solubilizing agents lecithin

Some of the major functional uses of lecithin products are as (1) emulsifiers in food emulsions, (2) solubilizing agents for various compounds in aqueous systems, (3) sol dispersing agents, and (4) foaming and defoaming agents. 

Lipids also can be beneficial for cells in culture, since some substances absorbed by the cells need to be solubilized in lipids, or in some cases the toxicity of compounds may be reduced by complexation with lipids. The absence of essential lipids such as linoleic acid, lecithin, cholesterol, ethanolamine, or phosphorylcholine can result in the decrease of cloning efficiency and in reduction in the size of colonies, as shown for insect cells by Echalier (1997). However, one of the difficulties in supplying lipids at reasonable concentrations is their low solubility. To circumvent this limitation, lipids can be emulsified with complexing agents such as Pluronic F68 or cyclodextrin (Maiorella et al., 1998). 

Answer Lecithin (see Fig. 10-14 for structure), an amphipathic molecule, is an emulsifying agent, solubilizing the fat (triacylglycerols) in butter. Lecithin is such a good emulsifying agent that it... 

The hydrophilicity of nonionic surfactants can be characterized numerically as their hydrophile-lipophile balance (HLB). An HLB value of 3-6 indicates that the compound is a likely W/O emulsifier 7-9, a wetting agent 8-13, an O/W emulsifier 13-15, a detergent and 15-18, a solubilizer (of oil or other nonpolar compounds) in water. The HLB values of some common compounds are presented in Table 34.12.170 An HLB value of 8.0 is shown in Table 34.12 for lecithin, but manufacturers are able to supply modified lecithins with values of2-12. 

To act as solubilizing, wetting, or emulsifying agents such as Cremophor EL, sodium desoxy-cholate, Polysorbate 20 or 80, PEG 40 castor oil, PEG 60 castor oil, sodium dodecyl sulfate, lecithin, or egg yolk phospholipid. 

Purified soybean lecithin Dispersing agent, emulsifying agent, solubilizer, stabilizer iv... 

After cyclodextrins and co-solvents, other approaches can be applied including the use of surfactants and micelle forming agents. Surfactants can be classified as amphoteric (lecithin), non-ionic (Tween 80 or Cremophor EF) or ionic (sodium lauryl sulfate or sodium palmitate). Cremophor is a polyoxyethylenated castor oil derivative which is a common solubilizing excipient in a number of formulations including those for paclitaxel, propofol, teniposide and clanfenur... 

Cholesterol gallstones — This type of stone is by far the most common—about 85% of the cases in the United States. Cholesterol is a whitish, waxy, fatlike material (lipid) which is almost insoluble in most body fluids unless it is held in solution—emulsified—by means of special complexes. In bile, cholesterol is emulsified and solubilized by a combination of bile salts and lecithin (phosphatidyl-choline). Hence, cholesterol may drop out of the bile when there is a shortage of either of the two types of emulsifying agents. 

Chem. Descrip. Lecithin, oleamide DEA, and soybean oil Uses Resorbable refatting agenL solubilizer, coemulsifier, and wetting agent for cleansing preps., hair care prods., men s toiletries Emutmin 40 [Sanyo Chem. Ind.]... 

Chem. Descrip. Hydrogenated lecithin Ionic Nature Amphoteric CAS 92128-87-5 EINECS/ELINCS 295-786-7 Uses Resorbable refatting agent solubilizer, gellant coemulsifier, and wetting agent for liposome preps., skin creams/lotions, nourishing preps. skin conditioner Properties Wh. powd., nearly odorless sol, 50 C in ethanol, hydrocarbons, chlorinated hydrocarbons disp. in water iodine no, 3 max,... 

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