4 Phases of clinical trial drug testing
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Posted On :
Jan-20-2012
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Article Word Count :
506
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Clinical trials are the studies of the effectiveness and safety of different drugs before making those available to public in the market. Clinical trials studies are conducted in 4 phases.
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Drug testing in clinical research: making a drug useful, checking its effectiveness and safety using several testing methods since the invention of the molecule to its placing on the market and up to the years of its uses.
Before being put on the market, any new medicine must prove its effectiveness and safety. Regulatory bodies such as the European Medicines Agency (EMEA), the Food and Drug Administration (FDA) in the United States and Indian Medical Association in India are responsible for establishing procedures for drug testing and to ensure their implementation.
Once a drug is considered promising, it switches to stage pre-clinical research, where it is tested in-vitro (ie in the laboratory, eg cell cultures) and in-vivo laboratory animals. This step is essential to ensure the safety of early stages of human trials. Clinical research in India is performed by several privately owned clinical research organizations and Indian Council of Medical Research as the government body.
If the drug passes the phase of pre-clinical testing, it enters phase of clinical research. The drug tests on humans are generally divided into four phases.
Drug trials: Phase 1
The phase 1 is the first drug administration in humans also known as first in man administration in India. It does not generally used to test the efficacy of the drug, but to assess its effect on human metabolism, its pharmacokinetics (that is to say the speed with which the drug is absorbed, distributed, metabolized and excreted by the human body), dosage and possible side effects. Phase 1 is generally performed on 20-80 healthy subjects. Very low doses of the drug is administered initially and then gradually increased.
Drug trials: Phase 2
Drugs that pass the first phase of clinical research are ready for the tests of Phase 2. During this, the drug is tested on a small group of patients who suffer from the disease that the drug is supposed to treat. This is a first measure of efficiency, but Phase 2 serves primarily to determine the best doses and routes of administration (oral, intravenous) and to confirm the test results of phase 1.
Drug trials: Phase 3
The Phase 3 is the first phase of clinical research where the drug is administered to a larger group of patients. It is to confirm the large-scale efficacy and safety of the drug. It can take several years and enroll several thousand patients. After this phase, the pharmaceutical company sends to the competent authority the application for authorization of placing the drug on the market. Based on the results of phases 1, 2 and 3, it accepts or rejects further investigations.
Drug trials: Phase 4
Once the drug is on the market, the pharmaceutical company can initiate on its own initiative or upon request of the competent authority, a study of phase 4. This allows us to test the drug on an even larger population or in specific sub-group to assess the long-term effects of the drug or to test for other indications.
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Article Source :
http://www.articleseen.com/Article_4 Phases of clinical trial drug testing_136645.aspx
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Author Resource :
A full service Indian CRO can be the cheapest place for clinical trials outsourcing, medical writing or clinical data management services
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Keywords :
Clinical trials, drug testing, Clinical research, clinical research organization, CRO in India,
Category :
Health and Fitness
:
Medicine
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