According to the process of drug research and development, new drug research and development can be divided into two stages: new drug preclinical research and clinical research. The former refers to the sum of all research work before the drug enters the clinical trial, and the latter refers to the research work completed by the drug in the clinical trial. From discovering that a drug is effective in animals to conducting clinical trials in humans, researchers need to do a lot of work to ensure that the drug’s potential for curative effects is maximized while minimizing its potential for harm.
This is the first stage of preclinical research. Each newly developed drug must be tested whether it is more effective than the original (drug) or whether it has other more desirable attributes. We must also consider whether this newly developed drug is less likely to cause harm, whether it can better enter the parts of the body that it needs, whether it is stronger so that a smaller dose can achieve the same effect, etc.
Finding the best compound involves a series of steps to optimize the drug, usually a series of experiments to chemically adjust the original molecule of the drug. Each new compound series needs to be tested until the developer selects the “best” compound from it, which has the highest potential for efficacy and the lowest possible side effects. The developer may select one or more at the same time. Development candidates.
“ADME” stands for: absorption, distribution, metabolism and excretion. This step is usually studied in parallel with the optimization process, including standardized studies to find out how “druggable” the compound is. Pharmacological properties refer to whether the compound can be transformed into a medicine that a doctor can prescribe.
▍ADME research needs to clarify:
(1) Whether the compound is stable (will it degrade before being used in patients);
(2) Determine what will happen if it is degraded, such as whether it will be transformed into certain toxic substances;
(3) Determine where the compound enters the body (whether it reaches the necessary muscles or improperly accumulates in the liver);
(4) Determine what will happen over time after the drug enters the body (whether it will accumulate until it becomes toxic, and whether the patient can excrete excessive ingredients)
If a compound fails in the ADME study, other different development candidates may succeed, so the researcher may return to the optimization process. At the end of this phase, researchers will obtain the lead compound with the most medicinal properties that can be further developed.
Choosing the appropriate mode of administration depends on the type of therapy under investigation. The mode of delivery may be very simple but it may also be very complicated. The feasibility of the drug delivery method depends on the nature of the therapy itself and the part of the body that requires the drug to reach. Generally speaking, low-dose drugs can be obtained by swallowing pills, but if high doses are required to act on specific tissues, such as a single muscle, the best way is to inject the drug directly into the muscle. Certain drugs, such as protein therapy, are digested by the gastrointestinal tract, so they need to be administered in other ways, such as intravenous or subcutaneous injections. For other drugs that require high concentrations to act on specific tissues of the body, the best way is to inject them directly into the corresponding parts.
Therefore, developers have to carefully evaluate how the drug is best delivered, and if the drug does not reach the required high enough level, it will not be effective. If the level of the drug is too high, there is a risk of harmful effects.