Skin irritancy testing

Generally speaking, up to now the importance of a-sulfo fatty acid esters in cosmetic products has been low [1 p. 367], In the future they may become more interesting because of their mildness. a-Sulfomethyl laurate and most other ester sulfonates are mild to the skin also, they are not human skin sensitizers or primary skin irritants. Tests have shown that a-sulfomethyl laurate is mild enough to be in bath products, such as bubble bath [62]. Three patents for different applications are given to show how ester sulfonates can be used in cosmetics. 

III 100 kg—1 tonne p.a. Public (including as part of a formulation) As Category It + eye irritation (unless skin irritation test positive) Skin sensitization... 

Two in vitro skin irritation tests EpiDerm SIT and SkinEthicTM RHE assay EU... 

Artificial skin models (EpiSkin , EpiDerm ) for skin irritation testing EU... 

Weil, C.S. and Scala, R.A. (1971). Study of intra- and interlaboratory variability in the results of rabbit eye and skin irritation tests. Toxicol. Appl. Pharmacol. 19 276-360. 

Society and Toxicology. (1989). SOT Position Paper, comments on the LD50 and acute eye and skin irritation tests. Fundam. Appl. Toxicol. 13 621-623. 

Skin irritation. Primary skin irritation tests run on this polyether indicate the material should be considered a very irritating substance. 

Hoechst Celanese Corp Primary Skin Irritation Tests with Eighteen Materials in Albino Rabbits EPA Document No. 86-890001277 Fiche No. OTS0520783, 07/27/92... 

The state of the art is a combination of linear low-density polyethylene (PE-LLD) with hmestone for diaper back sheets. By biaxial orientation, the balance of mechanical permeability requirements can be obtained. Because of its PE-like characteristics Ecoflex is a good choice for a biodegradable back sheet. Ecoflex provides a good regulatory basis for these applications because of the positive results of the primary skin irritation test according to OECD 404, as well as the guinea pig test according to OECD 406. 

Dermal. Dermal administration is required for estimation of toxicity of chemicals that may be absorbed through the skin, as well as for estimation of skin irritation and photosensitization. Compounds are applied, either directly or in a suitable solvent, to the skin of experimental animals after hair has been removed by clipping. Often dry materials are mixed with water to make a thick paste that can be applied in a manner that ensures adequate contact with the skin. Frequently the animals must be restrained to prevent licking and hence oral uptake of the material. Solvent and restraint controls should be considered when stress is involved. Skin irritancy tests may be conducted on either animals or humans, using volunteer test panels for human tests. 

P.A. Botham, L.K. Earl, J.H. Fentem, R. Roguet, and J.J.M. van dc Sandt, Alternative Methods for Skin Irritation Testing The Current Status, ECVAM Skin Irritation Task Force Report 1, ATLA, 26, 195-211, 1998. 

Table 3 Comparison of skin irritation test based on the Draize method...

York M, Basketter DA, Cuthbert JA, Nelson L (1995) Skin irritation testing in man for hazard assessment - evaluation of four patch systems. Human and Exper Toxicol 14 729-734 York M, Griffiths HA, Whittle E, Basketter DA (1996) Evaluation of a human patch test for the identification and classification of skin irritation potential. Contact Dermatitis 34(3) 204-212... 

Valid and accepted in vitro skin irritation test... 

In vivo skin irritation test (3 animals total)... 

Acute toxicity information on mineral spirits (as Stoddard solvent) is sparse. Short-term animal studies have shown depression of the CNS and irritation of the eyes, nose, and throat. Draize skin irritation tests on rabbits resulted in a final score of moderate . 

The principal distinction between transdermal and topical drugs is that only the former is intended for systemic delivery. Both are subject to the same skin irritancy testing prior to human exposures precli-nical and clinical skin irritancy testing is reasonably stereotypical and commodity priced. 

Dow. 1958. Results of range finding eye and skin irritation tests on Dowanol EB-crude (ethylene glycol, butyl ether). Dow Chemical Co., Biochemical Research Laboratoiy, Midland, MI. EPA/OTS No. 86-890001174. 

Jacobs GA, Castellazzi A, Dierickx PJ. 1989. Evaluation of a non-invasive human and an in vitro cytotoxicity method as alternatives to the skin irritation test on rabbits. Contact Derm 21(4) 239-244. 

It is unlikely that there will be significant percutaneous toxicity under the usual conditions of exposure to screening smokes. However, if primary and cumulative skin irritation tests suggest that there may be systemic effects, then it will be appropriate to conduct more detailed monitored studies for percutaneous toxicity. 

Toxicity. Mineral oils produce slight-to-moderate irritation by standard rabbit skin irritation tests (Beck et al., 1982 Mayhew et al., 1985). Repeated applications of mineral oils to skin over a week resulted in epidermal hyperplasia, hyperkeratosis, and depilation C14-C19 hydrocarbons caused more damage than C21-C23 hydrocarbons (Hoekstra and Phillips, 1963). 

Jones, J.R., Guest, R.L., and Warner, P.A., Diphoterine brevete official record concerning skin irritation test done in rabbits. Project Number 133/3, Study performed at Safepharm Laboratories, Ltd. Derby UK, Technical report. October 1987. 

As a next step, the formulation is tested using in vitro skin irritation tests such as the Zion test [16], collagen swelling test [17], or pH rise test [18], If the results of these tests show that the product is suitable for human clinical research, then it undergoes the following tests. 

In order to estimate the toxicity of the compound one must have data obtained at several dose levels and must see that there is a dose-related response. Further, there must be sufficient animals at each dose level so that the idiosyncracies of a few individual animals will not confuse the results. Excluded from this section are the consideration of eye and skin irritation tests, which have their own specialized scoring system previously discussed. 

Skin irritation test The skin irritation reaction is listed in table 5. Skin sensitization is an immunologically mediated reaction to a substance. In a human, the response can be characterized by pruritis, erythema, edema, papules, vesicles, bullae, or a combination of these. In other species, the reactions are different and only erythema and edema can be seen 14-15. The skin irritation reactions showed that there are no allergic responses, which indicated that the porous AI2O3 ceramics did not induce any immune reactions to guinea pigs. 

According to the results of cytotoxicity test, acute hemolysis test, skin irritation test, the in vitro biological reactions of the porous AI2O3 ceramics prepared via freeze casting is biosafe and can be further used in implant experiments. 

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