Compendium of the most significant studies with reference to properties, intake, effects.

Rütering M, Schmid J, Gansbiller M, Braun A, Kleinen J, Schilling M, Sieber V. Rheological characterization of the exopolysaccharide Paenan in surfactant systems. Carbohydr Polym. 2018 Feb 1;181:719-726. doi: 10.1016/j.carbpol.2017.11.086.

Abstract

Rheology-controlling agents are of importance for numerous products in a variety of industries. Replacement of synthetic chemicals with natural additives is desired in light of current environmental awareness and limited fossil resources. This study investigates the rheological features of Paenan, an exopolysaccharide produced by Paenibacillus polymyxa. Paenan exhibits highly shear-thinning flow behavior at concentrations ≥0.1% in 0.5% NaCl. Because of its pronounced intermolecular network, it forms stable, weak gels, thereby delivering elasticity as well as thixotropy. Application-relevant flow behavior is obtained with 60-65% less polymer as compared to the benchmark commercial products Xanthan and Gellan. In mixtures with surfactants (sodium lauryl ether sulfate, cetrimonium chloride, cocamidopropyl betaine, or lauryl glucoside), Paenan displays outstanding compatibility with every class of surfactant, making it superior to the partially incompatible Xanthan and Gellan. The weak-gel character of Paenan/surfactant systems is retained with three out of four surfactants, rendering Paenan highly interesting for various applications.

Mietz H, Niesen U, Krieglstein GK. The effect of preservatives and antiglaucomatous medication on the histopathology of the conjunctiva. Graefes Arch Clin Exp Ophthalmol. 1994 Sep;232(9):561-5. doi: 10.1007/BF00182000.

Abstract

Background: Topical medication applied chronically for the treatment of glaucoma changes the cellular profile of the conjunctiva. We wanted to determine the role of preservatives, which are usually combined with the drugs, on this effect.

Methods: We applied metipranolol 0.3% and pilocarpine 2% with and without benzalkonium chloride 0.01% and cetrimonium chloride 0.004%, respectively. Twenty-four rabbits, divided into four groups, were treated for 3 months. The complete globes and the adherent bulbar conjunctiva were examined histopathologically and immunohistochemically.

Results: With special stains for collagen, a slight increase of the thickness of subepithelial collagen of the conjunctiva was present in both groups treated with medication and preservative compared with eyes treated with medication alone. This effect was also true for special antibodies for collagen type IV and alpha-smooth muscle actin in the eyes treated with pilocarpine, but not in the eyes treated with metipranolol.

Conclusion: The results suggest that preservatives may have an additional adverse effect on the conjunctiva in addition to the effects of the medications alone.

de Araújo BRS, Linares León JJ. Electrochemical treatment of cetrimonium chloride with boron-doped diamond anodes. A technical and economical approach. J Environ Manage. 2018 May 15;214:86-93. doi: 10.1016/j.jenvman.2018.02.094.

Abstract

This study presents the results of the electrochemical degradation of the emulsifier cetrimonium chloride (CTAC) on a boron-doped diamond (BDD) anode under different current densities and flow rates. Higher values of these parameters result in a more rapid removal. Nevertheless, operation at low current reduces the required applied charge and increases the chemical oxygen demand (COD) removal efficiency, as there is less development of ineffective parasitic reactions. On the other hand, high flow rates reduce the required volumetric applied charge and increase the COD removal current efficiency. In order to assist and enrich the study, an economic analysis has been performed. For short expected plant lifespans, operation at low current is advantageous due to the lower investment required, whereas for longer expected lifespans, the operational costs make the lower current densities less costly. High flow rates are always advantageous from a financial point of view.