Preclinical toxicology study of new drugs

Definition of toxicology

Toxicology is the science of studying the harmful effects of toxic substances on body and its mechanisms, outcomes, and hazards. It is mainly used for safety evaluation and risk assessment of exogenous substances.

The tasks of drug toxicology include clinical toxicology, new drug clinical trials, and the task of drug epidemiology research. Its basic purpose is to understand and master the toxic effects of drugs, to provide a scientific basis for clinical safe medication and to avoid or mitigate the occurrence of these toxic effects in the course of medication. There are many types of toxic effects, including adverse drug reactions, side reactions, allergies, idiosyncratic reactions, and carcinogenicity.

The importance of preclinical reproductive toxicology research for new drugs

Preclinical safety evaluation is one of the key links in the development of new drugs. The main purpose is to determine the safety characteristics of drug candidates through evaluation, so as to provide experimental basis for further development. However, with the intensification of market competition and the rapid growth of investment in new drug research and development, the current routine safety evaluation methods are no longer sufficient. In addition, due to the increase in the number of new drugs, the country’s requirements for drug safety are also gradually increasing. These phenomena suggest the necessity of preclinical toxicology studies (e.g., vaccine reproductive toxicology study). Preclinical drug toxicology is a new discipline that studies the toxic effects of drugs and its mechanisms, and evaluates the safety of new drugs, including acute toxicity, repeated drug toxicity, safety pharmacology, special toxicity (genotoxicity, reproductive toxicity, carcinogenicity), toxicokinetics and other research. The purpose of the study was to find the symptoms of the toxic reaction of the drug, the duration of the onset and the end, the dose level of non-toxic reaction, the safe range of the dose and the dose of the toxic reaction, the nature and reversibility of the toxic reaction, and the like. The information obtained by the Institute of Drug Toxicology is an important basis for ensuring the safe use of drugs by patients. Therefore, preclinical drug toxicology research is a very important part of the development of new drugs.

What are the preclinical toxicology tests in vaccine development?

A vaccine is a general term for a variety of biological products containing antigenic substances that can induce specific active immunity in the human body. In preclinical studies of new vaccines, it is important to examine the safety of vaccines by conducting preclinical safety assessments of relevant animals. The drug safety evaluation in the preclinical study of new drugs refers to the use of drugs larger than the clinical dose, or longer than the clinical use time, to find and evaluate the potential toxic effects, toxicity performance, and reversibility of target organ damage. This study helps to identify toxic doses, detect toxic effects, determine safe dose ranges, find toxic target organs, and determine the reversibility of toxicity.

The difficulty in drug safety evaluation in preclinical studies of new vaccine drugs is that the vaccine itself does not directly exert its preventive or therapeutic effect, but acts by inducing the immune system to produce antibodies or activate T cells.