Dermal permeation of the sulfated fatty acid, ricinoleic acid, is inhibited by complex mixture additives.
Riviere-JE; Brooks-JD; Barlow-BM; Baynes-RE
Toxicologist 2003 Mar; 72(S-1):382-383
Performance of many cutting fluid formulations is dependent on its lubricant properties, which can often be improved by adding a sulfated fatty acid such as sulfated recinoleic acid (SRA). SRA like many of the other formulation ingredients are potential dermal irritants, yet little is known about its permeability in skin, and if other cutting fluid additvies influence its dermal permeation. The purpose of this study was to assess H3-SRA permeation when topically applied to inert silastic membranes and porcine skin in in vitro flow-through diffusion cell system as aqueous mineral oil (MO) or aqueous polyerhylene glycol (PEG) mixtures. H3-SRA mixtures were formulated will 3 commonly used cutting fluid additives; namely, 0 or 2% triazine (TRI), 0 or 5% linear alkyl benzene sulfonate (LAS), and 0 or 5% trierhanolamine (TEA). Formulation additives had little or no effect on SRA partitioning from the formulation into the stratum cornea (SC) in MO-based mixtures; However, in PEG-based mixtures the additives significantly decreased partitioning into the SC. The pH of SRA control and SRA+LAS mixture remained in physiological range (7.0 - 7.4), but all other mixtures were more basic pH (9.3 10.3). In silastic membranes, SRA absorption ranged from 1.22 to 12.840/0 dose and permeability and absorption were significantly reduced to one level by LAS and then another level by other additives or combination of additives in either MO- or PEG-based mixtures. In porcine skin, absorption ranged from 0.1 to 0.57% dose, and again formulation additives significantly decreased SRA absorption and permeability in both MO- and PEG-based mixtures. The observed decreasing trend of SRA permeation in born silastic and skin membranes is suggestive that this interaction is more physicochemical in nature than chemical-biological. The presence of other formulation additives that increased the pH of the mixture resulted in more charged SRA molecules that are not absorbed across the skin as readily.
Fatty-acids; Lubricants; Irritants; In-vitro-study; Fluids; Skin; Cutting-oils; Skin-irritants; Skin-exposure
Disease and Injury: Allergic and Irritant Dermatitis
The Toxicologist. Society of Toxicology 42nd Annual Meeting and ToxExpo, Cutting-Edge Science, Networking, New Perspectives, March 9-13, 2003, Salt Lake City, Utah
North Carolina State University, Raleigh, NC