Solubility sodium palmitate

In certain cases it is impossible to satisfy both and there is a decrease in solubility of the least successful component. For example, a soap such as sodium palmitate, which in water is mainly... 

Already in 1943 M. Schuler [2] described the comparison of the surface-active properties of sodium palmitate with several ether carboxylates based on a constant amount of C atoms. The results showed that with more O bridges the optimal surface activity and emulsifying properties can be achieved at lower temperature, with the detergent properties decreasing and solubility increasing. 

Addition of as little as 5% soap to an amphoteric LSDA of limited water solubility (high Krafft point) brought about a substantial lowering of the Krafft point and thus markedly improved water solubility. On the other hand, addition of 10% of amphoteric LSDA to sodium palmitate lowered the Krafft point of the soap by 10-14°C. Addition of anionic LSDA to sodium palmitate showed smaller Krafft point depression. Addition of a builder-type salt, such as sodium metasilicate, had essentially no effect on the Krafft points of soap-LSDA mixtures. 

Palmitate. Sodium palmitate. NaC16H3i02. white solid, soluble, froth or foam upon shaking the II2O solution (soap), formed by reaction of NaOH and palmitic acid (in alcoholic solution) and evaporating. Used as a source of palmitate. 

The hydrophilic part of the most effective soluble surfactants (e.g. soaps, synthetic detergents and dyestuffs) is often an ionic group. Ions have a strong affinity for water owing to their electrostatic attraction to the water dipoles and are capable of pulling fairly long hydrocarbon chains into solution with them for example, palmitic acid, which is virtually un-ionised, is insoluble in water, whereas sodium palmitate, which is almost completely ionised, is soluble (especially above its Krafft temperature - see page 93). 

Which do you think is the more soluble in water, sodium palmitate or ethyl palmitate In benzene ... 

The use of common antioxidants, such as water-soluble sodium bisulfate, sodium sulfite, sodium metabisulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, L- and D-ascorbic acid, acetylcysteine, cysteine, thioglycerol, thioglycollic acid, thiolactic acid, thiourea, dithithreitol or oil-soluble propyl gallate, butylated hydroxyanisole, butylated hydroxytoluene, ascorbyl palmitate, nordihydroguaiaretic add, and a-tocopherol is widely made in pharmaceutical formulations. Oxygen-sensitive substances should be screened for their compatibility with a range of antioxidants. One of the most commonly used antioxidants is metabisulfite. It should be noted that bisulfite has also been known to catalyze... 

Mixtures of fatty acid salts are used as soaps. Sodium palmitate—stearate mixtures are solid at room temperature, and the corresponding potassium salt mixtures are fluid, although only potassium palmitate has been crystallized at room temperature. Metal carboxylates hydrolyze in water and release hydroxyl ions on the skin s surface. Soaps with fewer than 12 carbon atoms therefore bite. This happens with nonpurified soaps as obtained from fats containing fractions. Longer alkyl chains produce soft soaps, since they are not soluble as monomers in water and the surface liquids of the skin (sebum, sweat). Sulfonates, on the other hand, do not show such differences because they are always present as fully dissociated salts at physiological pH values and produce no hydroxyl ions. Allergic reactions to commercial soaps are mostly not caused by the fatty acids but by additives, such as perfumes. 

Since saturated fatty acids are insoluble in bile acid solutions, and since saturated fatty acid soaps are only soluble in terms of the mole fraction of a soap-bile acid mixture having a critical micellar temperature of 37° C, one would anticipate saturated fatty acid-soap mixtures to have negligible solubility in bile acid solutions. Some years ago, we compared the behavior of sodium, palmitate, and stearate at pH 5.8, 6.2, 6.6, and 7.0 in buffer or buffer containing bile acid. In the absence of bile acid, the saturated fatty acids remained as unwetted crystals. When bile acid was added, the solubility increased measurably but only very slightly. 

Emulsion polymerization is similar to suspension polymerization in the sense that the reaction also takes place in the presence of a water phase and the applied monomer forms a second liquid phase. However, in this case the added radical initiator is not soluble in the monomer droplets but in the water phase. To allow the monomer to come into contact with the initiator an emulsifier is added to the reaction mixture that creates micelles in the systems. By diffusion processes both monomer molecules and initiator molecules reach the micelle. Polymerization takes places and a polymer particle suspended in the water phase forms that is much smaller than the original monomer droplet (see Figure 5.3.12 for a graphical illustration of these steps). At the end of the overall emulsion polymerization process, all monomer droplets have been consumed by the polymerization reaction in the micelles. Typical emulsifiers for emulsion polymerization are natural or synthetic detergents, such as, for example, sodium palmitate or sodium alkyl sulfonates. Emulsion polymerization is very versatile and is applied for many polymers [e.g., PVC, styrene copolymers, poly(methacryl esters)] in batch, semi-continuous, and continuous processes. In some cases, the obtained polymer particles in water are directly applied as technical products for coatings, lacquer applications, or as adhesives. In other cases the formed product is further treated to obtain the dry polymer. Note that the aqueous phase in emulsion polymerization always contains some isolated emulsifier and also some monomer. Moreover, the formed polymer contains the emulsifier as impurity. 

Peper showed [195] that in the presence of 1.8 X 10" M calcinm chloride, the adverse effect of these sodium soaps on both foamability and foam stability of a 3 X 10 M (1.0 g dm" ) sodium dodecylbenzene sulfonate solution was in the order sodium stearate sodium palmitate > sodium oleate > sodium laurate, which follows the order of solubility products of the corresponding calcinm soaps (calcium... 

Binary Soap-Water System Mixtures of soap in water exhibit a rich variety of phase structures (4, 5). Phase diagrams chart the phase structures, or simply phases, as a function of temperature (on the y-axis) and concentration (on the x-axis). Figure 2.1 shows a typical soap-water binary phase diagram, in this case for sodium pahnitate-water. Sodium palmitate is a fully saturated, 16-carbon chain-length soap. At lower temperatures, soap crystals coexist with a dilute isotropic soap solution. Upon heating, the solubility of soap increases in water. As the temperature is increased the soap becomes soluble enough to form micelles this point is named the Krafft point. The temperature boundary at different soap concentrations above which micelles or hquid crystalline phases form is named the Krafft boundary (5). 

The sodium palmitate—water system, which serves as a prototype for the solubility many ionic surfactants. (From Ref. 96, p. 50.)... 

The antibiotic is administered orally as the palmitate, which is tasteless this is hydrolysed to chloramphenicol in the gastrointestinal tract. The highly water-soluble chloramphenicol sodium succinate is used in the parenteral formulation, and thus acts as a pro-drug. 

The criteria for choosing inhibitors in this study were the ability to compete with diethanolamine for the nitrite and lack of toxicity. An attempt was made to cover as broad a group as possible within the limits of feasibility. Ascorbic acid in its water soluble form and its oil soluble form, the palmitate, represent the enediols, Sorbate is a diene fatty acid which has been shown to inhibit nitrosation (10), Since the pK of sorbic acid is 4,76, at the pH of these experiments, both water soluble sorbate ion and oil soluble sorbic acid are present in significant amounts. Sodium bisulfite is a strong inorganic reducing agent which has an acceptable lack of toxicity at the concentration... 

The selection of an appropriate antioxidant depends on factors such as stability, toxicity, efficiency, odor, taste, compatibility with other ingredients, and distribution phenomena between the two phases. Antioxidants that give protection primarily in the aqueous phase include sodium metabisulfite, ascorbic acid, thioglycerol, and cysteine hydrochloride. Oil-soluble antioxidants include lecithin, propyl gal-late, ascorbyl palmitate, and butylated hydroxytoluene. Vitamin E has also been used, but its virtue as a natural antioxidant has been the subject of some controversy. 

Sodium, potassium, and calcium salts of ascorbic acids are called ascorbates and are used as food preservatives. These salts are also used as vitamin supplements. Ascorbic acid is water-soluble and sensitive to light, heat, and air. It passes out of the body readily. To make ascorbic acid fat-soluble, it can be esterified. Esters of ascorbic acid and acids, such as palmitic acid to form ascorbyl palmitate and stearic acid to form ascorbic stearate, are used as antioxidants in food, pharmaceuticals, and cosmetics. 

Water that contains significant amounts of Ca2+ or Mg2+ is said to be hard. These ions cause soluble soaps such as sodium stearate, palmitate, and oleate to precipitate as insoluble scums, which are an unsightly nuisance as well as a waste of soap ... 

Oleic acid may be obtained from glycerol trioleate, present in many liquid vegetable and animal nondrying oils, such as olive, cottonseed, lard, by hydrolysis. The crude oleic acid after separation of the water solution of glycerol is cooled to fractionally crystallize the stearic and palmitic acids, which are then separated by filtration, and fractional distillation under diminished pressure. Oleic acid reacts with lead oxide to form lead oleate, which is soluble in ether, whereas lead stearate or palmitaie is insoluble, prom lead oleate oleic add may be obtained by treatment with IL 5 (lead sulfide, insoluble solid, formed). With sodium oleate, a soap is formed. Most soaps are mixtures of sodium stearate, palmitate. and oleate. 

Calcium soaps such as calcium stearate, calcium palmitate, and calcium abietate are made by the action of the sodium salts of the acids on a soluble calcium salt such as calcium chloride (CaCl2). 

Another approach, artificial hydrophobization of polypeptides with a small number of fatty acid residues (e.g. stearate or palmitate) has been showm to enhance cellular uptake (Kabanov et al., 1989a). Specifically, this technique involves point modification of lysine or N-terminal amino groups with one or two fatty acid residues per protein molecule. As a result of such modification, the protein molecule remains water-soluble but also acquires hydrophobic anchors that can target even very hydrophilic proteins to cell surfaces (Slepnev et al., 1995). To obtain low and controlled degrees of modification, a system of reverse micelles of a surfactant, sodium bis-(2-ethyIhexyl)sulfosucciate (Aerosol OT) in octane was used as a reaction medium (Kabanov et al., 1987) (Figure 47.4). Over a... 

Oil-in-water creams, for topical use, generally contain mixed emulsifiers/surfactants one of which is a water soluble surfactant with a high HLB, the other being an amphiphile, usually a long chain fatty alcohol (e.g., of chain length C14 to Cig) or acid (e.g., palmitic or stearic). The water soluble surfactant may be anionic (e.g., sodium lauryl sulphate), cationic (e.g., cetri-mide), or non-ionic (e.g., cetomacrogol. Tweens). 

The simplest and most common synkinons are non-branched, saturated fatty acids from C12 to C18 (trivial names lauroyl Cl2, myristoyl Cl4, palmitoyl or cetyl Cl 6, stearoyl Cl8) and their sodium, ammonium and potassium salts (also known as soaps ). Laurie, myristic, palmitic and stearic acids are barely soluble in water at 20°C (5.5, 2.0,0.7 and 0.3 mg/L) and 60°C (8.7, 3.4, 1.2 and 0.5 mg/L), each ethylene group lowering the solubility by a factor of 2-3. The solubilities of the corresponding sodium and potassium salts are, however, in the order of several grams per litre. Even in highly concentrated emulsions of soaps in distilled water ( 30% w/w), precipitation of solids is often not observed. Bivalent fatty acid salts, however, are just as insoluble as free fatty acids only 1.4 mg of calcium stearate dissolves in 1 L of water. ... 

Description, identification, specifications, and tests of L-ascorbic acid and sodium L-ascorbate are given in the U.S. Pharmacopoeia 15) and the Food Chemicals Codex 16). Similar information on palmitoyl L-ascorbic acid (ascorbyl palmitate) is contained in the Codex. Sodium ascorbate is twice as soluble in water as ascorbic acid. Ascorbyl palmitate is soluble in ethanol (25°C) at 12.5%, in hot (80°C) glycerin, propylene glycol, or decaglycerol octaoleate to 10%, in vegetable oils (25°C) at 0.01--0.1% and in water (70°C) at 0.2%. 

A water-soluble formulation of chloramphenicol sodium succinate is available for i.v. use. Chloramphenicol succinate is hydrolyzed to chloramphenicol in the liver. Chloramphenicol palmitate is an insoluble ester suitable for p.o. administration. Chloramphenicol palmitate is hydrolyzed to chloramphenicol in the gastrointestinal tract. Chloramphenicol (generic and veterinary labeled) is also available in a variety of tablet and capsule strengths. A long-acting formulation of florfenicol is approved for i.m. and s.c. administration to cattle. This formulation contains three carriers... 

Palmitic acid and stearic acid are colorless, wax-like substances, which melt at 63° and 69°, respectively. They are insoluble in water, but dissolve in organic solvents. The sodium and potassium salts of the acids are soluble in water, while those of calcium, magnesium, and the heavy metals are insoluble. Both acids have the normal structure, that is, the alkyl radicals which they contain, C15H31, and C17H3B, respectively, consist of carbon atoms united in a straight chain. 

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