MOLECULE TO MEDICINE :- A JOURNEY

Nowadays, a lot of medicines are available in the market for treating various medical conditions and they are being used by the people on a wide scale. Anyone ever wondered, how much efforts, trials, money and time it takes to discover, develop, manufacture and sale that medicine. Well, it would all be discussed here.

Before any medicine reaches market, it has to pass through various critical testing stages. This stages are designed to check whether the medicine is safe, effective for intended purpose and to find out suitable dose and dosage form for the medicine. The milestones in the journey of medicine could be named as follows:

• Discovery and Development
• Pre-clinical Research
• Clinical Research
• FDA Drug Review
• Marketing & Post-Marketing Surveillance

It may take about 10-15 years to complete this journey and then, finally, the medicine reaches the market for the use in patients.

Lets have a brief look at the journey:

1. Discovery and Development

• This initial step involves a lot of literature study for understanding the disease, finding out all the potential molecule candidates which could treat the disease condition, knowing about the current treatment methods and studying all the previous research articles or reports regarding the condition and molecule.
• This molecules are also commonly termed as "DRUG MOLECULE".
• These drug molecules are tested in the laboratory and from among all these compounds, a single promising molecule is selected.
• This single molecule then enters the phase of development where various information regarding the molecule is studied like its ADME (Absorption, Distribution, Metabolism and Elimination) data, its mechanism of action, benefits, side effects, adverse effects, interaction with other molecules, its affect on different group of people (based on gender, ethnicity, race), appropriate dose, etc.

2. Pre-Clinical Research

• This phase provides the information regarding the toxicity of the molecule before being tested on the human beings
• This studies are of two types: one being "in vivo studies" and another is "in vitro studies"
• In vivo studies are performed inside the animals while the in vitro studies are performed outside the body by creating an environment similar to the internal body.
• while performing this tests, researcher must follow the Good Laboratory Practice (GLP) guidelines.

3. Clinical Studies

• Preclinical studies give us the information about the safety of the molecule, but those information could not be used for developing a medicine for human use.
• Hence, it is necessary to test that medicine in human beings and this testing is named as Clinical Studies. 
• Clinical studies are performed in four phases : Phase 1, 2, 3, and 4.
• Phase 1 trials are performed on 20-100 healthy volunteers for determining safety and dose while in phase 2 and 3, trials are performed on patients for determining the efficacy and side effect of the medicine. The only difference between this to phase is the number of patients included in the study i.e. phase 3 studies are performed on more patients. Phase 4 is a post marketing surveillance stage which is performed after the medicine reaches the market.
• Before initiating the clinical trials, sponsor must take permission from FDA by filing IND (Investigational New Drug) Application. This application must contain the information regarding Animal study data, Manufacturing Information, Clinical Study Protocol and Data from any prior human studies.
• Researcher must inform FDA regarding any serious side effect encountered during the clinical studies. He must also submit the report after the completion of trials.

4. FDA Drug Review

• After collecting clinical studies data, the sponsor should file New Drug Application (NDA) to the FDA. This application must contain sufficient information, clearly indicating that the medicine is safe and effective for intended use in targeted population.
• This application must include the data from the preclinical studies to phase 3 studies, proposed labeling, drug abuse information, patent information, Institutional Review Board (IRB) compliance information, Direction of use, etc.
• FDA will check the file. If it is incomplete then FDA will refuse the application and if its complete then FDA will take 6-10 months to approve the medicine.

5. Marketing & Post-Marketing Surveillance

• After getting approval from the FDA, the respective company should initiate manufacturing and marketing phase.
• The manufactured medicines are first sent to the wholesalers in bulk quantity who in turn sell them to the retail pharmacy stores from where the patients could have access to those medicines. 
• Also the post marketing surveillance should be performed at regular time intervals and reports should be submitted to the respective authority.
• This report should include the information on any adverse effects seen after the medicine has reached the market.
• If those adverse reactions are serious and life threatening then the company must stop the supply of medicines and it should also inform the authority about the same.