Masters in clinical research

Phase I trials
This is the first time the new drug is administered to a small number, around 20- 80 healthy, informed Volunteers under the close supervision of a doctor which may take several months to complete. The study is designed to determine the effects of the drug on humans including how it is absorbed, metabolized, and excreted. This phase also investigates the side effects that occur as dosage levels are increased. About 70% of experimental drugs pass this phase of testing.

Phase II trials
In this phase, the medicine is administered to a group of approximately 100-300 patients to determine the efficacy of the drug. Most phase II studies are randomized trials where one group of patients receive the experimental drug, while a second "control" group receives a standard treatment or placebo. Often these studies are "blinded" which means that neither the patients nor the
researchers know who has received the experimental drug. This allows investigators to provide the comparative information about the relative safety and effectiveness of the new drug. About one-third of experimental drugs successfully complete both
Phase I and Phase II studies.

Phase III trials
It involves randomized and blind testing in several hundred to several thousands of patients and can last for years; this provides a more thorough understanding of the effectiveness of the drug, the benefits and the possible adverse reactions if any. If the results are favorable, the data is presented to the licensing authorities for a commercial license.

Phase IV trials
It is also called as Post Marketing Surveillance. This is a Surveillance operation phase after the drug has been approved for consumer sale. The main objectives at this stage is : (1) to compare a drug with other drugs already in the market; (2) to monitor a drug's long-term effectiveness and impact on a patient's quality of life; and (3) to determine the cost-effectiveness of a drug therapy relative to other traditional and new therapies. Phase IV studies can result in a drug being taken off the market or restrictions on use could be placed on the product depending on the findings in the study.