Lauryl sulphate

Since poly(vinyl acetate) is usually used in an emulsion form, the emulsion polymerisation process is commonly used. In a typical system, approximately equal quantities of vinyl acetate and water are stirred together in the presence of a suitable colloid-emulsifier system, such as poly(vinyl alcohol) and sodium lauryl sulphate, and a water-soluble initiator such as potassium persulphate. 

Other additives that may be incorporated include sodium hydrogen phosphates as buffering agents to stabilise that pH of the reaction medium, lauryl mercaptan or trichlorethylene as chain transfer agents to control molecular weight, a lubricant such as stearic acid and small amounts of an emulsifier such as sodium lauryl sulphate. 

Dispersant solution. Prepare a 1 per cent aqueous solution of sodium lauryl sulphate. 

Fig. 5.5 Chromatogram ofchlor-prothixene hydrochloride CRS which contains 2.7 % ofthe f -isomer. (Column 4 x 120 mm hypersil BDS [3 pm]. Mobile phase 6.0 g potassium dihydrogen phosphate, 2.9 g sodium lauryl sulphate, 9.0 g tetrabutylammonium bromide 550 ml water, 50 ml methanol and400 ml acetonitrile, flow rate 1.5 ml/min and detection wavelength 254 nm.)...

Liegeois (71), using 400.0 ml of water, 280.0 gr of VCM, 280.0 mgr of potassium persulphate initiator and 2.5 gr of sodium lauryl sulphate emulsifier at 50°C, measured by electron microscopy PVC latex particle diameters close to 190 A for a conversion level of 24%. The model predicted an average particle diameter equal to 200 A for the same conversion level and for the same experimental conditions. 

Cumberbatch, M., et al., Influence of sodium lauryl sulphate on 2,4-dinitrochlorobenzene-induced lymph node activation. Toxicology, 11, 181, 1993. 

The surface active agents (surfactants) may be cationic, anionic or non-ionic. Surfactants commonly used are cetyltrimethyl ammonium bromide (CTABr), sodium lauryl sulphate (NaLS) and triton-X, etc. The surfactants help to lower the surface tension at the monomer-water interface and also facilitate emulsification of the monomer in water. Because of their low solubility surfactants get fully dissolved or molecularly dispersed only at low concentrations and at higher concentrations micelles are formed. The highest concentration where in all the molecules are in dispersed state is known as critical micelle concentration (CMC). The CMC values of some surfactants are listed in table below. 

In certain specific cases either the pure pharmaceutical substance or dosage forms are quantitatively converted to free compound. This conversion to free compound is quantitative and hence forms the basis of gravimetric analysis. A few typical examples belonging to this category are, namely progesterone suspension sterile, progesterone tablets, sodium lauryl sulphate, mephobarbital tablets and sorbitan monooleate. 

Qiang, D., Gunn, J. A., Schultz, L., Li, J. Evaluation of the impact of sodium lauryl sulphate source variability on solid oral dosage form development. Drug Dev. Ind. Pharm., 36(12), 2010, 1486-1496. 

Neutral detergent fibre (NDF) Sodium lauryl sulphate, EDTA, pH 7.0 Boil for 1 h Herbage cell wall minus pectins... 

Use only sodium dodecyl sulphate (sodium lauryl sulphate) or Aerosol 22, at... 

Mathur AK, Agarwal C, Singh A, et al. 1988. Effect of sodium lauryl sulphate and nickel alone and in combination on the skin of guinea pigs. Toxicol Lett 42 249-256. 

Mathur AK, Gupta BN, Singh S, et al. 1992. Cutaneous toxicity of sodium lauryl sulphate, nickel, and their combination in guinea pigs Biochemical and histopathological observations. Bull Environ Contam Toxicol 49 871-878. 

A selection of the results obtained 29) for the emulsion copolymerization of 1 with styrene at 10 °C using sodium lauryl sulphate as emulsifying agent and Rongalit / H202/Fe2+ as initiator are given in Table 3.4. 

Table I. Rate constants of the energy transfer from ]MPT (HO M) to Ni2+ and Co2+ in solution (ethanol/water l/2) and aqueous lauryl sulphate micelles (18).

Tupker, R.A., J. Pinnagoda, and J.P. Nater. 1990. The transient and cumulative effect of sodium lauryl sulphate on the epidermal barrier assessed by transepidermal water loss Inter-individual variation. Acta Derm Venereol (Stockh) 70 1. 

Grangsjo, A. et al., X-ray microanalysis of cultured keratinocytes methodological aspects and effects of the irritant sodium lauryl sulphate on elemental composition, J. Microsc., 199, 208, 2000. 

De Paepe, K., Roseeuw, D., and Rogiers, V., Repair of acetone- and sodium lauryl sulphate-damaged human skin barrier function using topically applied emulsions containing barrier lipids, J. Eur. Acad. Dermatol. Venereol., 16, 587, 2002. 

Rosenkranz et al. have also identified a total of 13 different CASE biophores and 7 biophobes for Draize eye irritation (Rosenkranz et al., 1998). These included structural features on 2,4-dihydroxybenzoic acid and sodium lauryl sulphate. In the case of a quantitative prediction of the eye irritation potential of 2-methylbutyric acid, the ocular irritation potential of the chemical was predicted to be high and was assigned a value of 49 CASE units. 

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