New Drug Development and Approval

New Drug Development and Approval Process

Word Count (including title and citations): 932

The development of new medicines is an arduous process. Identifying a new compound for drug use in a research laboratory is the seminal step which proceeds through the drug development process. Before a drug is approved marketing for general public use, the sponsor of the drug (e.g. The pharmaceutical company), must show that the drug is safe and effective for the proposed use.

This is done through the support and carefully documented scientific evidence. Furthermore, the sponsor must assure that production processes and controls, including manufacturing, packaging, and labeling, meet established standards of quality. The development process for new drugs includes five basic steps: Preclinical Studies, Investigational New Drug Application, Clinical Trials, New Drug Application, and Approval.

Prospective new drugs must complete preclinical testing to be evaluated for potential therapeutic usefulness. In the preclinical studies, the new chemical compound is tested for safety and effectiveness in research laboratory and animal studies. These tests offer empirical data on how it is absorbed, distributed, stored, metabolized and excreted in living organisms. Its effects on cell structure are also evaluated. These tests involve careful evaluation in several disciplines including pharmacology, toxicology, and formulation.

Pharmacology is a branch of medicine that is concerned with drug action. More specifically it examines interactions that affect biochemical function between chemicals and living organisms. This discipline is further divided into Pharmacokinetics and Pharmacodynamics studies. Pharmacodynamics can be summed up as a study of effects the drug has in the body; while pharmacokinetics is the study of what the body does to a drug. Studies in pharmacokinetics essential evaluate the biochemical and physiological effects of drugs and their mechanism of action. It considers the extent and rate of distribution, absorption, excretion, and metabolism. The purpose of these studies is to verify the safety and usefulness of the chemical compound in order to determine the value of continued development. Pharmacodynamics studies the biochemical and physiological effects of drug substances on living organism. It also evaluates the mechanism of drug action in the body.

Toxicology would measure any adverse effects of the new compound on living organisms in this stage of evaluation the living organism are observed carefully for any signs of adverse symptoms or detection of poisoning of any kind. Toxicologists observe and measure both acute and chronic toxic effects. The new drugs are also tested for carcinogenicity, cancer causing, and Mutagenicity, effect on gene mutation.

While pharmacology, toxicology assess new drugs for biological activity, steps in formulation evaluate the chemical and physical properties. Formulated proceeds in two stages: pre-formulation and formulation. The pre-formulation stage addresses the chemical and physical traits of the new drug to assure a stable formulation and optimum drug delivery. Such things as drug solubility, partition coefficient, dissolution rate, physical form, and stability are evaluated. Initial product formulation utilizes knowledge acquired from pre-formulation outcomes to derive proper dose, dosage form, and type of administration for the proposed marketed use. A pilot batch of Clinical Trial Materials (CTM) may be produced after the new drug has completed these initial tests.

Upon completion of preclinical testing, the drug sponsor files an Investigational New Drug Application (IND) with the U.S. Food and Drug Administration (FDA), after they have obtained prerequisite approval from the Institutional Review Board (IRB). The purpose of the investigation is to assure that the new drug is safe and meets stated objectives for human consumption. Among other things, all formulations must meet FDA Current Good Manufacturing Practice guidelines before human testing can begin. Ordinarily, the FDA has 30 days to respond to the application. After the drug receives this initial approval clinical trials may begin within 30 days.

Clinical trials proceed in four phases, with each phase increasing in number of test subjects and duration. Phase I verifies safety of the new drug entity; 67% of drugs successfully complete Phase I. Phase II evaluates the drug's effectiveness; 45% of drugs have a Phase II positive outcome. Phase III verifies efficacy and ascertains possible adverse reactions in large populations; 5-10% of drugs successfully complete this phase. Lastly, Phase IV concentrates on post-marketing surveillance which seeks to identify adverse reactions that are rare and go undetected during previous studies, monitor known reactions, and identify other risk factors.