Draize rabbit tests

Primary irritant-contact dermatitis results from direct cytotoxicity produced on first contact. The cellular injury is characterised by two macro-scopically visible events a reddening of the skin (erythema) and accumulation of fluid (oedema). By observing or measuring these changes, one can estimate the extent of skin damage that has occurred. The most widely used single-exposure irritancy test is based on the Draize rabbit test. ... 

Ocular damaging and irritant agents can be identified and evaluated by the Draize rabbit test [114]. However, more recently this test has been criticized on the basis of ethical considerations and unreliable prognosis of human response. Alternative methods such as the evaluation of toxicity on ocular cell cultures have been recommended and are being indicated as promising prognostic tools [115-120]. Direct confocal microscopic analysis [121], hydration level of isolated corneas [122], and various other tests on isolated corneas or animal eyes have also been proposed for evaluation of ocular toxic effects. 

Only a few in vivo dermal toxicity studies have been reported so far. Huczko and Lange [50] evaluated the potential of raw CNTs to induce skin irritation by conducting two routine dermatological tests (patch test on 40 volunteers with allergy susceptibilities and Draize rabbit eye test on four albino rabbits). Koyama etal. [51] showed the biological responses to four different types of carbon nanotubes (SWNTs, two types of MWNTs with different diameters, and cup-stacked carbon nanotubes) after their subcutaneous implantation in mice. Both tests [50, 51] showed no or poor irritation effects. However, the in vitro studies in epidermal cell lines exposed to CNTs, and also a more recent report on the toxic outcomes of topical exposure of mice to SWNTs [46], have raised concerns over these assessments. Clearly, this is an area requiring further scientific evaluation. 

Toxic responses in the eye can result from direct topical ocular exposure of drugs from direct installation into the eye and also from dermal products which patients may accidentally get into their eyes. Until recently, the Draize rabbit eye test using three rabbits has served as the major protocol to assess the irritancy potential of topically applied substances. 

The application of all three alternative tests before the Draize skin test would result in 21 chemicals being tested on rabbits, of which just two would be corrosive. The effect of applying the most predictive two-step sequence (steps 2—>3) would be the testing of 25 chemicals on rabbits, of which just two chemicals would be found corrosive. If only one alternative test, the EPISKIN test, were applied before the Draize test, then 30 chemicals would be tested on rabbits, of which four would be corrosive. The best stepwise strategy that can be constructed from the CMs reported... 

Abraham MH, Hassanisadi M, Jalali-Heravi M et al. (2003) Draize rabbit eye test compatibility with eye irritation thresholds in humans a quantitative structure-activity relationship analysis. Toxicol Sci 76 384-391 Curren RD, Harbell JW (1998) In vitro alternatives for ocular irritation. Environ Health Perspect 106, Suppl 2 485M92 Draize JH, Woodard G, Calvery HO (1944) Methods for the study of irritation and toxicity of substances applied topically to the skin and mucous membranes. J Pharmacol Exp Ther 82 377-390... 

York M Steiling W (1998) A critical review of the assessment of eye irritation potential using the Draize rabbit eye test. J Appl Toxicol 18 233-240... 

All Draize-type tests evaluate corrosion and irritation by using albino rabbits as subjects (Table 3). The Federal Hazardous Substance Act (FHSA) adopted one modification as a standard procedure to this method (1997). 

Methods of testing for eye and skin irritation potential have been reviewed (163). The official FHSA procedure for evaluating ocular irritation potential of detergent products is a modified Draize rabbit eye test (164). Some controversy surrounds this method at present, and a search for a procedure less injurious to test animals is in progress. In general, the order of irritation is cationic > anionic > nonionic (165). 

The ensuing limited within- and between-laboratory reproducibility of the Draize rabbit eye test [5, 21-24],... 

The Isolated Rabbit Eye (IRE) test has been developed as an in vitro alternative to the in vivo Draize rabbit eye test method for the assessment of eye irritation [68]. In the IRE assay, liquid test substances are spread using a syringe and solids are pulverized and applied as a powder over the corneas of enucleated rabbit eyes. The test [also referred to as the Rabbit Enucleated Eye Test (REET)] makes use of eyes from animals used in the food chain or for other toxicological studies. 

Ocular administration of 1,1,1-trichloroethane caused only mild eye irritation in rabbits (Duprat et al. 1976 Krantz et al. 1959 Marzulli and Ruggles 1973 Torkelson et al. 1958). The study by Marzulli and Ruggles (1973) was a survey in which 10 laboratories conducted the Draize eye test in rabbits using 1,1,1-trichloroethane and reported little or no eye irritation. 

MMT. Hinderer (1979) performed a standard Draize irritation test with commercial neaf MMT in rabbits... 

Over the years a numbo of alternative test systems have been described in the literature. These include the use of tissue culture, excised animal organs, bactoial systems, computer modeling, protozoan mortality inhibition, chorioallantoic membrane inflammation, and specific biochemical reactions [23]. Most of these alternative test procedures have been proposed or developed with the objective of reducing or replacing animal LDjg toxicity tests and the controversial Draize rabbit eye irritancy test [24]. 

The Draize rabbit eye irritation test [175] has been used for decades as an animal model to predict eye irritation in humans. However, because the rabbit eye does not tear, and of course the human eye does, this model is imperfect for predicting irritation to human eyes. Obviously, the rabbit eye test cannot be used to evaluate no more tears shampoo claims. A large number of laboratory models have been examined over the past decade to provide a predictive tool to be used either in place of or to minimize the use of animals for eye testing. Among these models, the HET-CAM test and the CAM-VA assay show the most promise [176]. 

All the official recommended methods for determining the ocular Irritation potential of a chemical derive from the Draize rabbit eye test (Draize et al., 1944). Despite of its historical impact, to day most scientists as well as the general public are disapproved of the Draize test for ethical and scientific reasons (Sharpe, 1985, Swanston, 1985). A number of in vitro test systems were described, e.g. the isolated eyes (Price and Anders, 1985), the embryonated hen s egg-choriallantoic membrane (HET-CAM) test (Luepke, 1985), the neutral red/kenacid blue method (Borenfreund and Puermer, 1985 Knox et al., 1986 Riddell et al., 1986), or the EYTEXR method (Martin, 1993 Regnier, 1994). 

Many surfactant suppliers classify their raw mliterials in terms of skin irritation using the Draize Skin Test [48]. The Draize test is used to investigate dermal irritation by the test material. Undiluted products are applied for 24 h under semiocclusive patch tests on the backs of albino rabbits. Dermal irritation is evaluated 24 and 72 h after patch removal, on the basis of the formation of erythema/eschar or edema. Follow-up readings are usually done in the case of a strong reaction. 

Major validation studies took place in the 1990s to replace the Draize test for eye irritation testing (Balls et al., 1995 Gettings et al., 1996 Spielmann et al., 1996 Bradlaw et al, 1997 Brantom et al, 1997 Ohno et al, 1999). Good reproducibility and reliability of the most valuable alternative methods have been demonstrated, but so far it has not been possible to identify a single method able to replace the Draize rabbit eye test. This is due to different factors including the limited quality of the existing in vivo data, limitations of... 

The hen s egg test on the chorioallantoic membrane (HET-CAM assay) enables irritant reactions to be identified that are similar to those which occur in the eye using the standard Draize rabbit eye test. In the HET-CAM test system, three reactions are determined, namely, haemorrhage, lysis and coagulation (sometimes hyperemia is also used as a parameter) of the CAM on the ninth day of embryonation when nerve tissue and pain perception have not yet developed (Figure 9.1.4). 

In a broad evaluation also the sulfosuccinate disodium laureth sulfosuccinate (DLSS) was a part of a variety of surfactants tested for their dermatological mildness, and some different test methods were applied [16]. Products were compared applying in vitro methods (Zein test, hemolysis) and in vivo methods (Duhring-Chamber test, skin mildness by intracutaneous test on mice and topical application on hairless mice, mucous membrane irritation according to the Draize procedure on rabbit eyes). In the Duhring-Chamber test the DLSS elicited no reactions in the animal tests it ranged in the least irritant third of the 15 products tested. 

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