PRACTICAL APPLICATIONS OF QSAR TO IN-VITRO TOXICOLOGY ILLUSTRATED BY CONSIDERATION OF EYE IRRITATION

Mechanistically based quantitative structure-activity relationships (Q SARs) have been developed for some well defined toxic endpoints. Princ ipal components analysis has proved to be a useful technique in visual izing the QSARs and allows ready construction of hypotheses to test. T he preferred way of testing the hypotheses is to use in vitro methods: thus integrating the use of QSAR and in vitro methods. Principal comp onents analysis affords a basis for more rational selection of test ch emicals to examine the utility of an in vitro method and more specific ally the selection of test chemicals to be used in the validation of a n in vitro method. This is particularly important in the absence of a large number of chemicals which have been tested in animals. In additi on, elucidation of the putative mechanism of action of chemicals allow s re-evaluation of the appropriateness of an in vitro method for the p recise detection of the toxicity of specific classes of substances and more rational design of in vitro methods with improved powers of pred iction.