Regulating Botanical Drugs

In the United States, a botanical product can be a food, a dietary supplement, or a drug, and botanicals have a long history of use in each of these categories. This article focuses on the gray area where a botanical product crosses from dietary supplement use into the realm of a drug, i.e., where the intended use is for diagnosing, mitigating, or treating or curing disease, and thus is classified as a drug according to the Federal Food, Drug and Cosmetics (FFD&C) Act.

Botanical drugs have many characteristics that distinguish them from synthetic or highly purified drugs. They may come from a single plant or from a mixture of plants, and have significant variability in their ingredients depending on their origin and time of harvest. They may also contain multiple active constituents that are not easily identified, and be produced using traditional methods that are difficult to standardize. As a result, the United States Food and Drug Administration (FDA) published a draft guidance document[1] to assist industry in the development of botanical drugs. This guidance outlines when a botanical drug may be marketed under an over-the-counter (OTC) drug monograph and when FDA regulations require submission of an approved new drug application (NDA). It also discusses several areas in which FDA finds it appropriate to apply regulatory policies that differ from those applied to synthetic or highly purified drugs.

Because of the unique nature of botanical drugs, the documentation on the chemistry, manufacturing, and controls will often be different from that for synthetic or highly purified drugs, whose active constituents may be more readily identified and quantified. For example, the FDA would expect an NDA for a synthetic or highly purified drug to identify the active ingredient. However, it would not be essential for the sponsor of a botanical drug to identify the active constituents, although the FDA recommends that this be done if feasible. Because many botanical products are legally available in the United States as dietary supplements, there is often very little new animal toxicological data needed to initiate clinical studies in humans, as long as there are no known safety issues associated with the product and it is to be used at approximately the same dose as those currently recommended. However, the Investigational New Drug (IND) application for botanicals products that have a previous marketing history in the United States should include the common or usual name of the plant, alga, or macroscopic fungus, the name of the family, genus, species, and variety, and the chemical class of the active constituents for each of the botanical raw materials. The sponsor should also provide information from the historical and scientific literature on the use of the botanical product, as well as information on its current marketed use. For botanical products that have been previously marketed in a foreign country, but not in the United States, the sponsor must provide sufficient information to assist the FDA in determining the safety of the product for use in initial clinical studies. This supporting information should include a signed certificate of authenticity of the plant and plant parts, data that support safe human use (including the rate of adverse effects), an estimate of the size of the exposure population, and the annual sales volume.

Because of the complex nature of a typical botanical drug, the FDA relies on a combination of tests and controls to ensure the identity, purity, quality, strength, potency, and consistency of its constituents. These include multiple tests for the drug components (e.g., spectroscopic and/or chromatographic fingerprints, chemical assays of characteristic markers, and biological assays), strict quality controls for the botanical raw materials, and adequate in-process controls. Despite differences in procedures, the regulatory pathway for marketing botanical drugs is simplified compared with that for synthetic or highly purified drugs, and there has been increased interest in the development of botanical drugs as evidenced by the increased number of IND submission over the past ten years.

Reference

[1] Available at http://www.fda.gov/cder/guidance/1221dft.htm