Therapeutic index assessment is a critical component of preclinical testing for new drugs, chemicals, and other substances. The therapeutic index is a measure of the safety and efficacy of a substance, calculated as the ratio of the dose required to produce a therapeutic effect to the dose that produces toxic effects.

The primary objective of therapeutic index assessment is to determine the safety and efficacy of the substance at different doses and to identify the dose range that achieves the desired therapeutic effect while minimizing toxicity. These studies involve the administration of the substance at different doses to laboratory animals, and the evaluation of its effects on a range of endpoints, such as pharmacokinetics, pharmacodynamics, and toxicity.

The therapeutic index is calculated by dividing the dose required to produce a therapeutic effect by the dose that produces toxic effects. The therapeutic index provides a measure of the safety and efficacy of the substance, with higher values indicating a wider margin of safety and a greater potential for therapeutic use.

Therapeutic index assessment is an important part of the preclinical safety and efficacy assessment of drugs and other substances, and is required by regulatory agencies before clinical testing in humans can be initiated. The results of therapeutic index assessment can help identify the appropriate dose range for subsequent clinical trials, and can inform decisions about the safety and efficacy of the substance for use in humans.