Polyoxyethylene 968 INDEX

The difficulty with HLB as an index of physicochemical properties is that it is not a unique value, as the data of Zaslavsky et al. (1) on the haemolytic activity of three alkyl mercaptan polyoxyethylene derivatives clearly show in Table 1. Nevertheless data on promotion of the absorption of drugs by series of nonionic surfactants, when plotted as a function of HLB do show patterns of behaviour which can assist in pin-pointing the necessary lipophilicity required for optimal biological activity. It is evident however, that structural specificity plays a part in interactions of nonionic surfactants with biomembranes as shown in Table 1. It is reasonable to assume that membranes with different lipophilicities will"require" surfactants of different HLB to achieve penetration and fluidization one of the difficulties in discerning this optimal value of HLB resides in the problems of analysis of data in the literature. For example, Hirai et al. (8 ) examined the effect of a large series of alkyl polyoxyethylene ethers (C4,C0, Cj2 and C 2 series) on the absorption of insulin through the nasal mucosa of rats. Some results are shown in Table II. 

Other synthetics derived from petroleum, having high viscosity index, low volatility, and low pour point, include polyoxyethylene and polyoxypropylene monohydroxy compounds (22). These can be made by an addition reaction between a monohydric alcohol and an alkylene oxide. 

Refractive index data are very useful for the quantitation of isotropic (liquid and cubic liquid crystal) phases, and for the calibration of cell thickness and nonflatness. Hovever, the analysis of birefringent phases using refractive index data has been found to be unreliable (9). A problem arises from the fact that the orientation of such phases relative to the direction of the light path, as veil as the system variables, influence refractive indices. In order to use refractive index data for quantitation, a phase must spontaneously orient in a reproducible fashion. Such orientation does occur in the case of fluid lamellar phases (as in short chain polyoxyethylene nonionic systems (7)), but viscous lamellar phases, hexagonal phases, and crystal phases do not orient to a sufficient degree. 

Figure 2. Relationship between the number of moles of ethylene oxide in octyl- or nonyl-phenol polyoxyethylene glycol ether surfactant molecules and the toxicity index of these surfactants in mixtures with (a) paraquat and (b) dalapon on corn plants.

Figure 3. Relationship between the number of moles of ethylene oxide in octylphenol (%), nonylphenol ( ), or laurylphenol ( J) polyoxyethylene glycol ether surfactant molecules and the toxicity index of these surfactants in mixtures with (a) paraquat, (b) dalapon, and (c) amitrole on corn plants. Herbicides applied at 1/64, 10, and 5 lb./ acre, respectively surfactant concentration was 0.005M in all cases. Toxicity index calculated by expressing fresh weight for each treatment as percentage of untreated control and subtracting this value from 100 (58)...

A list of more than 200 additional journals has been made from the bibliographies of books and reviews, indexes, and abstracts. This is evidence of the fact that the cereal chemists enjoys the universal predicament of all scientists. It points out clearly his dependence on abstracts and indexes, not only for maintaining inroads to past experience and inventions, but for keeping abreast with current literature. The cereal chemist, for example, may or may not have seen the article in the Journal of Colloid Science entitled The Action of Polyoxyethylene Monostearate upon Starch with Reference to Its Softening Action in Bread (8). 

The flux of liver TG to the plasma can be evaluated by intravenous administration of certain non-ionic surface-active agents. Intravenous injection of TRITON WR-1339 (a polyoxyethylene polymer) has a trapping effect on plasma lipoprotein-bound TG while it does not affect the rate of TG secretion from the liver. Thus, the extent of the hyperlipaemia is an index of the magnitude of the flux of liver TG to plasma in the rat it has been calculated to be of the order of 0 1 mg/min per 100 g body weight... 

Chiu, Y. C., L. J. Chen, Refractive index of nonionic surfactant solutions containing polyoxyethylene mono-n-alkylether. Colloids Surf., 1989,41,239-244. 

Szymanowski, J., A. Voelkel, H. Szewczyk, Increments of the arithmetic retention index for nonionic surfactants with a polyoxyethylene chain, J. Chromatogr., 1986,360,43-52. 

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