Buehler test

FIGURE 15.4. Line chart for modified Buehler test for delayed contact dermal sensitization in the guinea pig. 

S. Frankild, A. Volund, J. E. Wahlberg, and K. E. Andersen. Comparison of the sensitivities of the Buehler test and teh guinea pig maximization test for predictive testing of contact allergey. Acta Derm. Venereol. 80 256-262 (2000). 

There are currently three OECD test guideline methods for test of skin sensitization in animals. These include the Guinea-Pig Maximization Test (GPMT), the Buehler test, and the murine Local Lymph Node Assay (LLNA). 

A negative result in this type of test indicates that the potential to sensitise is extremely low and that human exposure is unlikely to be attended by a significant incidence of sensitisation. Because the test can be overpredictive, some toxicologists recommend that a non-adjuvant test such as the Buehler test should be used if a positive is obtained, to give a more realistic determination of the prevalence of human sensitisation, it should be remembered that contact sensitisation is a persistent condition thus once sensitised to a chemical, an individual is at risk of dermatitis whenever exposed to the same or antigenically cross-reactive chemical, for example, nickel in jewellery. 

Guinea pig OECD 406 (modified Buehler test) Nonsensitizing... 

Ecoflex (powder) was tested for its sensitizing effect on the skin of the guinea pig in the modified Buehler test according to OECD guideline 406. Skin-sensitizing effects were not observed in these animal studies. 

Adjuvant and patch test Buehler test Drciize test... 

The GPMT of Magnusson and Kligman (which uses adjuvant) and the nonadjuvant Buehler test are given preference over other methods and these procedures are described in detail. 

Briefly, the standard Buehler test uses three 6 h dermal patches, one per week, to the same shaved site. After a 2 week rest period, the test animals and half of the control animals receive another 6h patch at another site. Then, the test animals are tested again 7-15 days later. Reactions are graded according to a five-point scale. If the results are equivocal, the animals may be rechallenged 1 week later. 

The dose level will depend on the test method selected. In the Buehler test, the concentration of the induction dose should be high enough to cause... 

Basketter DA, Gerberick GF (1996) Interlaboratory evaluation of the Buehler test. Contact Dermatitis 35 146-151... 

The Buehler test (Buehler 1964) also employs topical application of the test material. An absorbent patch or vehicle alone is placed on the shaved flanks of 10-20 guinea pigs. Test concentration varies from undiluted to usage levels. A concentration that produces slight erythema is optimum and is selected based on an irritancy screen conducted in other animals. This procedure is repeated 7 days and 14 days after the initial exposure. Two weeks after the last induction patch, animals are challenged with patches saturated with a non-irritating concentration of test material and with the vehicle. After 6 h, the patch is removed and the area depilated. Test sites are visually evaluated 24 h and 48 h after patch removal. Animals developing erythematous responses are considered sensitized (if irritant control animals do not respond). 

Buehler test is less sensitive and may underestimate the sensitisation potential of a substance. The limitation of the tests is that the evaluation is based on visual inspection of erythema and personal judgement. For these reasons, evaluation of coloured test substances, e.g. pigments and dyestuffs, is often impossible due to staining of the skin by the test substance. 

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