Pharmacokinetic stage: the process of absorption, distribution, metabolism and elimination of drugs in the body.

Pharmacokinetics, also known as pharmacokinetics, is a quantitative description and summary of the administration process of drugs through various routes (such as intravenous injection, intravenous drip, oral administration, etc.) by applying kinetic principles and mathematical models. ) absorption (absorption), distribution (distribution), metabolism and excretion (elimination) into the body, that is, the "dose-time" change or "blood drug concentration-time" change during absorption, distribution, metabolism and excretion (ADME).

Pharmacokinetics studies the relationship between the level and time of drug metabolites in various body fluids, tissues and excreta, and studies the mathematical relationship needed to explain these data models. Pharmacokinetics has become the most important and close foundation of biopharmaceutics, pharmacology, toxicology and other disciplines, which has promoted the vigorous development of these disciplines. It is also closely related to basic disciplines such as mathematics, chemical kinetics and analytical chemistry.

It has developed rapidly in recent 20 years, and its research results have played an important role in guiding the design of new drugs, optimizing dosage forms, improving dosage forms, and providing drugs with high efficiency, quick effect, long term effect, low toxicity and low side effects.

Extended data:

First of all, pharmacokinetics, as a science dealing with the dynamic process of drugs in vivo by mathematical analysis, has great theoretical value and is an important part of "mathematical pharmacy".

Its basic analytical methods have penetrated into biopharmaceutics, clinical pharmacy, pharmacotherapy, clinical pharmacology, molecular pharmacology, biochemistry, analytical chemistry, pharmacy, pharmacology and toxicology and other scientific fields, which have become the most important and close foundation of these disciplines and promoted their vigorous development.