Answer: Each year many new prescription drugs are approved by the Food and Drug Administration(FDA). The process of developing and bringing new drugs to market is very important.

It starts from the synthesis and extraction of new molecules with the potential to produce a desired change in a biological system. The process may require: 1) research on the fundamental mechanisms of disease or biological processes; 2) research on the action of known therapeutic agents; or 3) random selection and broad biological screening.

Then it goes to a process of biological screening and pharmacological testingThese tests involve the use of animals, isolated cell cultures and tissues, enzymes and cloned receptor sites as well as computer models. Each compound has been tested to see which version of the molecule produces the highest level of pharmacological activity and demonstrates the most therapeutic promise, with the smallest number of potentially harmful biological properties.

After Pharmacological testing the drug undergoes toxicology and safety testing. Tests provide information on the dose-response pattern of the compound and its toxic effects.

Finally, it goes to the process of turning an active compound into a form and strength suitable for human use . A pharmaceutical product can take any one of a number of dosage forms e.g., liquid, tablets, capsules, ointments, sprays, patches The final formulation will include substances other than the active ingredient, called excipients. Excipients are added to improve the taste of an oral product, to allow the active ingredient to be compounded into stable tablets, to delay the drug’s absorption into the body, or to prevent bacterial growth in liquid or cream preparations. The impact of each on the human body must be tested.

For drugs that appear safe, an investigationalnew drug application is filed with the FDA. If approved, clinical trials begin with phase 1 studies that focus on safety and pharmacology. Phase 2 studies examine the effectiveness of the compound. Phase 3 is the final step before submitting a new drug application (NDA) to the FDA. An NDA contains all the information obtained during all phases of testing. Phase 4 studies, or postmarketing studies, are conducted after a product is approved.

The Drug Approval Process:

An application filed with the U.S. Food and Drug Administration  (FDA) prior to human testing. The IND application is a compilation of all known information about the compound. It also includes a description of the clinical research plan for the product and the specific protocol for phase I study.

The new drug approval process involves the following phases:

Clinical Evaluation, Phase 1: Examines the pharmacologic actions and safe dosage range of a drug; how

it is absorbed, distributed, metabolized, and excreted; and its duration

of action Clinical evaluation

Clinical Evaluation, Phase 2 :Controlled studies in volunteers to assess the effectiveness of a drug.

Simultaneous animal and human studies can continue to examine

further the safety of the drug

Clinical Evaluation, Phase 3: Testing using a greater number of volunteer patients. The drug is

administered by practicing physicians to those suffering from the condition the drug is intended to treat. These studies must confirm earlier efficacy studies and determine low-incidence adverse reactions Clinical evaluation.

Then an application has been made by the manufacturer to the FDA for approval to market a new drug. All information about the drug gathered during the drug discovery and development process is assembled in the NDA. During the review period, the FDA may ask the company for additional information about the product or seek clarification of the data contained in the application.

Clinical Evaluation, Phase 4 Studies conducted after FDA approval, during general use of the drug by medical practitioners. Also referred to as postmarketing studies

Phase 4 studies are an important source of information on as yet undetected adverse outcomes, especially in populations that may not have been involved in the premarketing trials (e.g., children, the elderly, pregnant women) and the drug’s long-term morbidity and mortality profile.