In the preclinical step the drug is tested for Pharmacodynamics (PD), Pharmacokinetics studies (PK), DMPK/ADME, Toxicology and In Vivo testing disease models. In the process of drug discovery and development preclinical studies refers to the stage before the new chemical/molecule entity is sent for clinical trails.
Preclinical data is gives us insights on
- Pharmacokinetics (PK) Properties – Pharmacokinetics describes how the body affects a specific drug after administration through the mechanisms of liberation, absorption distribution and excretion, as well as the metabolic changes of the substance in the body. The effects and routes of excretion of the metabolites of the drug.
- Pharmacodynamical (PD) Properties – It is the study of the biochemical and physiologic effects of drugs, is shows how a drug affects an individual’s body. In simple terms it is the response of the body towards the drug. A drug’s pharmacodynamics can be affected by physiologic changes due to a disorder, aging or other drugs.
- Disorders that affect PD responses include genetic mutations, thyrotoxicosis, malnutrition, myasthenia gravis, Parkinson disease and few types of insulin-resistance. These disorders can change receptor binding, alter the level of binding proteins.
- Aging tends to affect PD responses through changes in the receptor binding
- PD drug to drug interactions result in competition for receptor binding sites.
- Drug Toxicity – Toxicity screening of new chemical entities is essential for drug development process. Drug toxicity is also referred as drug intoxication. Toxicity testing can be done through In Vitro studies using cell lines or In Vivo human disease models in animals.
- Asses the Therapeutic Window/Index (TI) –The range of doses which is to be optimize between efficacy and toxicity, achieving the greatest therapeutic benefit without resulting in unacceptable side-effects or toxicity. Before the clinical trials it is very important for the drug discovery team to know the TI, if the dose is above the therapeutic window it may lead to toxicity.