An easy and new method for the quant. evaluation of creaming for oil-in-water emulsions used absorption measurements of a dye dissolved in the oil phase prior to the emulsion prepn. The measurements were carried out by dissolving samples, withdrawn at different intervals from the bottom of the stored emulsions, in Me2CO, to obtain clear colored solns. The technique was suitable to predict the tendency of an emulsion to undergo creaming. The proposed method has been compared to known methods for droplet size evaluation, and a good correlation was obtained. [on SciFinder(R)]

A review with 22 refs. The compn. of amino acids in kidney stone matrixes and inhibitory materials from normal urines is discussed. The amino acid factor (FAA) proposed is FAA = (Glutamic acid)/(Aspartic acid + Alanine); its value in fractions of non-potent inhibitory material and in kidney stone matrixes is \textless0.6. In potent portions of the inhibitory material sepd. from healthy people and young animals' urine the value is ≥0.8. The role of enzymes in calcium oxalate stone formation and the exptl. evidence of acidic amino polymers and monomers effect on calcium oxalate crystn. are also discussed. [on SciFinder(R)]

Bromination of the arom. ring of ethoxylated nonylphenols produced surfactants which were effective emulsifiers for oil-in-water emulsions and which had slightly higher HLB values than their nonbrominated analogs. The bromination increased the sp. gr. to values higher than that of water, allowing formation of oil-in-water emulsions with denser droplets. Initial bromination caused an increase in viscosity while further bromination decreased viscosity. The refractive index increased with increasing oxyethylene chain length and bromination. Crit. micelle concns. for the brominated surfactants were lower than those for the nonbrominated surfactants. Bromination decreased the surface excess concn. values for the compds. [on SciFinder(R)]

The esterification of glyceryl monostearate [31566-31-1] with maleic anhydride [108-31-6] was studied by anal. wet and GLC methods to parameterize and optimize the reaction and maximize the desired yield. Prolonged esterification and temps. \textgreater110-120° increased the diglyceride and hydrophobic product yield. Higher molar ratios of ester to anhydride increased esterification yield. The mechanism and kinetics of the reaction were also detd. [on SciFinder(R)]

Food Grade Rutile (TiO2) was dispersed in coconut oil with the help of hydrophobic emulsifiers such as sorbitan esters and lecithin. The dispersed mixt. was melted and blended with hydrophilic emulsifiers such as ethoxylated sorbitan esters and the preheated (60°) blend was further sprayed by atomizer into cold water (20°). The oil-in-water emulsions contained encapsulated TiO2 in the internal phase. The technique is simple and allows prepn. of stable emulsions with av. droplets size of 1-10 $μ$. [on SciFinder(R)]

Ethoxylated oleyl alc. or esters and selected derivs. behave abnormally in aq. solns. When plotting ln (CMC) vs. the no. of ethylene oxide (EO) units of the unsatd. compds., neg. slopes are obtained, while pos. slopes are expected for the corresponding satd. surfactants. Prepn. of dihydroxy-, dichloro-, and dibromostearyl ethers or esters of ethoxylated surfactants and selected polyglycerol esters confirmed these anomalies. No common intercept is expected for such compds. at 0 EO units. An explanation based on steric hindrance of the surfactant on micelle packing is proposed. [on SciFinder(R)]

Bromination, chlorination, and hydroxylation of the hydrophobic chains of com. available polyethylene glycol oleyl ether [9004-98-2], polyethylene glycol monooleate [9004-96-0], and polyglycerol esters resulted in surfactants with improved hydrophobic properties and unchanged hydrophilic moieties. The modified surfactants stabilized paraffinic oil in water emulsions. The derivatization of the nonionic surfactants increased their HLB value. The ability of the surfactants to stabilize the emulsions was not due to increased sp. gravities but rather due to the fact that better steric arrangement on the interface was obtained. [on SciFinder(R)]

A method for the prepn. of transparent emulsions for cosmetic applications consists of adding water and a blend of 2 emulsifiers (sorbitan fatty acid esters and their ethoxylated derivs.) to iso-Pr myristate (I) [110-27-0] followed by homogenization. The use of excessive emulsifiers decreased the emulsion stability. The best emulsion stability was obtained with 7, 9, 10, and 15% (by wt.) of emulsifier blend for 20, 30, 40 and 50% I. An ideal compn. contained 20% I and 5% emulsifier. Emulsions prepd. with water, in the absence of polyols, were stable even after 12 mo storage. The stability of the sorbitol [50-70-4] emulsion was improved by adding anionic emulsifiers such as triethanolamine oleate [2717-15-9] to the nonionic blend. Thus, combinations of triethanolamine oleate and sorbitan esters and ethoxylated sorbitan esters improved the emulsion stability. [on SciFinder(R)]

The dissocn. const. of stearic acid dimer was detd. in four different solvents, using a Fourier transform IR technique. The $Δ$H obtained for each solvent decrease as the solvation of stearic acid increases. The results are relevant to the crystn. process of stearic acid from soln. which may lead to different polymorphic forms depending on the different crystn. parameters. [on SciFinder(R)]

Unsatd. fatty acids of soybean and castor oils were isomerized to conjugated forms and thermally polymd. or crosslinked to obtain emulsifiers for oil-water emulsions. The emulsifying agents were prepd. in 3 ways. The oil was transesterified with glycerol to obtain mono/diglycerides which were heated to 290° to give crosslinked polyglycerol esters. The emulsifiers were also prepd. by treating the soybean or castor oil with polyglycerols previously prepd. The 3rd case involved crosslinking the oil by a transesterification reaction 12 h at 290° to give a dimerized oil which was then transesterified with polyglycerol. A mixt. contg. 3% of the above-prepd. crosslinked polyglycerol esters, 40% water, and 50% soybean oil was easily emulsified to form a nonviscous stable water-in-oil emulsion. [on SciFinder(R)]

The polymorphic behavior of cocoa butter in the presence of several food emulsifiers serving as crystal structure modifiers was investigated. Emphasis was placed on transitions among the relatively stable forms IV, V and VI, which are significant for a confectionery industry. As known from industry work, within the series of sorbitan esters and ethoxylated sorbitan esters, the solid emulsifiers were the most efficient in retarding transition of V form into VI modification. Blends of sorbitan monostearate (Span 60) [1338-41-6], ethoxylated sorbitan monostearate (Tween 60) [9005-67-8] and Span 60-Tween 65 [9005-71-4] were particularly effective. Surprisingly, some combinations of emulsifiers accelerate the transition of form IV into form V. Transition of form V into form VI occurs via the solid state, and other transitions are known to take place via the liq. phase. Emulsifiers increased liq. fraction of the fat prior to its transition. Mechanistic considerations concerning these transitions are suggested. [on SciFinder(R)]

The effects of some nonionic surfactants on the kinetics of the soln.-mediated transition of stearic acid [57-11-4] of B and C polymorphs were studied. Some surfactants retard the transition of the thermodn. unstable stearic acid modification to the stable form in methanol, n-hexane and decane solns. The surfactants consisting of large hydrophilic moieties revealed a significant retardation effect. The effect also depends on the solvent; the lower the soly. of the surfactant in the solvents, the more the transition rate was decreased. The C→B transition was more affected than the B→C transition with a given surfactant. [on SciFinder(R)]

The release of electrolytes from water-oil-water (W/O/W) emulsions was studied. A significant difference was obsd. in the release of NaCl and org. ion (ephedrine-HCl [50-98-6]). The rate of release decreased with the increase of the initial concn. of the electrolyte. A kinetic model which is similar to the model for release of dispersed drugs from a polymeric matrix was suitable for the release of electrolytes from multiple emulsions. [on SciFinder(R)]