Their aims are to identify mechanisms of chemically-induced biological activity, prioritize chemicals for more extensive toxicological evaluation, and develop more predictive non-animal based models of in vivo biological response. Hopefully, this research will lead to toxicity models that are more scientific and cost-effective as well as models for risk assessment that are more mechanistically-based.

Despite the advances, the resulting mechanism-based assays need validation or at least profound scientific evaluation before they can be used routinely. Often, the appropriate prediction evaluation occurs in parallel with assay development and ultimately leads to the streamlining of the assay. Parameters such as stability

of solutions, proteins or even cell lines should be checked selleck screening library and standardized. PD0332991 price Incubation times, storage, robustness (replicates for statistical analysis) are also some of many considerations companies make when validating assays ( McGee, 2006). The main priority for all industry sectors is the safety of the products and thus for people, animals and the environment and doing this with a reasonable the number of animals used and, in the case of the cosmetics industry, to replace in vivo assays entirely. Some of the priorities were discussed in break-out groups (each containing representatives from academia and industry and in some, representatives FAD from regulatory bodies) from the workshop and are listed below. The sector(s) to which the priority applies most is shown in brackets. Topics that were discussed were not necessarily the views of all those who participated. Through discussions in the workshop, it was concluded that in order to interpret in vitro data, a number of considerations need to be made which include: • Are in vivo

and in vitro concentrations the same and is the in vitro concentration relevant to in vivo? There are many variables in metabolism assays which may affect their outcome; therefore, harmonization of these assays is needed. The harmonization of toxicity tests according to OECD guidelines began in the early 1980s. In addition the testing of the safety and efficacy of drugs is harmonized by the International Conference on Harmonisation (ICH). This has led to the effect of not just standardizing tests but reducing the number of animals used, since regulatory agencies around the world now accept the results of a test conducted according to such guidelines. Nevertheless, researchers have to work hard to convince regulators and the scientific community that some in vitro/in silico methods are sufficiently reliable to be used, albeit not yet for systemic toxicity endpoints.