Drug development process is a very sluggish process that involves years to launch in the market. Billions of dollars are spent on them because they are the survival imperative for most of the pharmacy companies. Drug development process involves a series of stages mainly the pre-clinical stage and the clinical stage.
The pre-clinical stage involves studying about the various parameters for a drug by testing on animals. During the pre-clinical drug development process stage the drug undergoes a test to determine the toxic and pharmacological effects on animals. This is mainly done through in vitro and in vivo laboratory animal testing. Few of the tests like Genotoxicity, absorption speed, toxicity of its metabolites and the time in which the drug and its metabolites are excreted from the animal body are determined. In short the pre-clinical stage of drug development involves:
i) Creation of pharmalogical outline of the drug.
ii) Testing and determining the acute toxic effect of that drug in at least 2 species of animal
iii) Lastly conducting the toxicity studies ranging from a week to 3 months for clinical studies.
After this comes the clinical stage that is divided in many sub-stages or phases:
Phase I- The main motive of this phase is to the safety profile of the drug. The drug’s metabolic and pharmacological effects are tested on around 20-100 healthy humans. During this phase the side-effects are also determined.
Phase-II- This phase mainly involves the effect of drug on a particular disease or symptom, involving around few hundreds of humans the results are closely monitored.
Phase-III – This phase is an extension of the Phase-II. Once the effectiveness and other evidence of the drug have been determined they further tested to evaluate the overall benefit-risk relationship of the drug, involving several hundred to several thousands of people this time.
Phase-IV- The last phase also known as the Post Marketing Surveillance phase is done when the product is approved and launched in the market.