Pharmacology new drug pharmacology

A new drug refers to a drug whose chemical structure, drug composition or pharmacological action are different from those of existing drugs. China's Drug Administration Law stipulates that new drugs refer to drugs that have not been produced in China; Changing the dosage form, changing the route of administration, adding new indications or making new compound preparations also belong to the scope of new drugs.

New drug research and development is a systematic project with high technology content, large investment, long cycle, high risk and high benefit. It is also a very strict and complicated process, and each drug is different, so pharmacological research is an essential key step. It is of great significance to protect people's health and develop the national economy to continuously discover and provide new drugs that are safe, efficient, adaptable to the disease spectrum and controllable in quality.

New drugs generally go through the stages of innovation and development from discovery to production to clinical application. In the innovation stage, it is necessary to design the effective components of synthetic or purified products and screen them on pathological models, so as to find compounds with development value, that is, lead compounds. Then study the structure-activity relationship of lead compounds, and carry out process research, preparation research, quality control, pharmacodynamic evaluation, safety evaluation, clinical pharmacological research and so on. According to the relevant provisions of the national new drug approval.

Under the guidance of practical experience or theory, new drugs can be found through synthesis and screening. The research process of new drugs can be roughly divided into preclinical research, clinical research and post-marketing monitoring. Preclinical research mainly includes medicinal chemistry research and pharmacological research. The former includes the process, physical and chemical properties and quality control standards of pharmaceutical preparations, while the latter conducts pharmacodynamics, pharmacokinetics and toxicology studies based on experimental animals that meet the Regulations on the Administration of Experimental Animals. Clinical research is divided into four stages:

Phase I clinical trial is a preliminary pharmacological and human safety test conducted on 20 ~ 30 normal adult volunteers, which is the initial stage of human trials of new drugs and provides scientific basis for follow-up research.

Phase II clinical trial is a randomized, double-blind controlled trial, with no less than 100 cases observed, mainly to preliminarily evaluate the effectiveness and safety of new drugs and recommend clinical dosage.

Phase III clinical trial is an expanded multi-center clinical trial before new drugs are approved for marketing and during trial production. No less than 300 cases were observed, and the effectiveness and safety of new drugs were investigated in society. New drugs can only be produced and marketed after passing clinical trials.

Phase Ⅳ clinical trial is to evaluate the safety and effectiveness of new drugs in a wide range of social groups after the drugs are put on the market, and to investigate the curative effect and adverse reactions under the condition of long-term extensive use, also known as after-sales investigation. This period is of great significance to the final determination of the clinical value of new drugs.

At present, the concept of phase 0 clinical trial has been put forward in the research and development field. Phase 0 clinical trial is a kind of research limited to traditional phase I clinical trial, aiming at evaluating the pharmacodynamics and pharmacokinetics characteristics of the tested drugs. It is characterized by small dosage, short cycle, few subjects and no purpose of efficacy evaluation. Its purpose is to evaluate the pharmacodynamics and pharmacokinetics of candidate anti-tumor drugs acting on target indicators and/or biomarkers.