title: Mixture additives inhibit the dermal permeation of the fatty acid, ricinoleic acid.
abstract: Ricinoleic acid (RA) like many of the ingredients in machine cutting fluids and other industrial formulations are potential dermal irritants, yet very little is known about its permeability in skin. 3H-ricinoleic acid mixtures were formulated with three commonly used cutting fluid additives; namely, triazine (TRI), linear alkylbenzene sulfonate (LAS), and triethanolamine (TEA) and topically applied to inert silastic membranes and porcine skin in vitro as aqueous mineral oil (MO) or polyethylene glycol (PEG) mixtures. These additives significantly decreased ricinoleic acid partitioning from the formulation into the stratum corneum (SC) in PEG-based mixtures. Except for LAS, all other additives produced a more basic formulation (pH = 9.3-10.3). In silastic membranes and porcine skin, individual additives or combination of additives significantly reduced ricinoleic permeability. This trend in ricinoleic acid disposition in both membranes suggests that the mixture interaction is more physicochemical in nature and probably not related to the chemical-induced changes in the biological membrane as may be assumed with topical exposures to potentially irritant formulations.
authors.affiliation: Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA. ronald_baynes@ncsu.du
authors.forename: R E
authors.initials: RE
authors.lastname: Baynes
authors.forename: J E
authors.initials: JE
authors.lastname: Riviere
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D004129:Dimethylpolysiloxanes; D004338:Drug Combinations; D004983:Ethanolamines / Q000737:chemistry / Q000493:pharmacokinetics; D005260:Female; D007219:Industrial Oils; D008567:Membranes, Artificial; D009924:Organ Culture Techniques; D010539:Permeability; D014677:Pharmaceutical Vehicles / Q000737:chemistry / Q000493:pharmacokinetics; D012277:Ricinoleic Acids / Q000737:chemistry / Q000493:pharmacokinetics*; D012828:Silicones; D012867:Skin / Q000187:drug effects* / Q000378:metabolism; D012869:Skin Absorption; D013552:Swine; D014227:Triazines / Q000737:chemistry / Q000493:pharmacokinetics; D014316:Tritium
chemical_list: D017738:Alkanesulfonic Acids; D004129:Dimethylpolysiloxanes; D004338:Drug Combinations; D004983:Ethanolamines; D008567:Membranes, Artificial; D014677:Pharmaceutical Vehicles; D012277:Ricinoleic Acids; D012828:Silicones; D014227:Triazines; C030641:alkylbenzyl sulfonic acid; D014316:Tritium; C013830:baysilon; C009546:triethanolamine; C030521:ricinoleic acid