ety of new applications. Its continuing story is recounted here—a story that offers insights into the development process—and a description of additional cannabinoids under development is provided. Finally this chapter assesses the outlook for new marijuana-based drugs as well as prospects for marketing whole marijuana as medicine.
Under the federal Food, Drug, and Cosmetic Act, the FDA decides whether a drug is sufficiently safe and effective to enter the marketplace. The agency bases its decision on evidence assembled from clinical trials conducted by the drug's sponsor. Pharmaceutical companies sponsor the majority of clinical trials, but academic and government laboratories also participate in drug development. For example, the National Institutes of Health funds collaborative programs to promote the commercial development of drugs for conditions such as AIDS, cancer, addiction, and epilepsy. Such programs supported most of the research that brought dronabinol to market.
Drug development begins with a compound that has either been synthesized in a chemical laboratory or purified from a natural source. If scientists find it has a useful biological activity, they will proceed to test the compound in animals in order to determine its effects on whole organisms. For example, after discovering that a compound extracted from a plant binds to receptors on nerve cells involved in appetite stimulation, researchers might perform tests to see if the compound could actually cause mice to increase their food consumption and gain weight. Such early experiments, which occur before human testing of an experimental medicine, are known as the preclinical phase of drug development.
When evidence from animal research suggests that a drug should be safe and effective in humans, the manufacturer submits an Investigational New Drug (IND) application to the FDA. The IND submission contains a plan for human clinical trials and documents the results of preclinical testing. If the FDA does not contest the IND within 30 days, the manufacturer may proceed to conduct clinical tests of the new drug in humans.