According to 21 CFR 210.3(b)(8), an inactive ingredient is any component of a drug product other than the active ingredient. Only inactive ingredients in the final dosage forms of drug products are in this database.
The Inactive Ingredient Database (IID) provides the information on inactive ingredients present in FDA-approved drug products. This information can be used by formulation scientistto develop anew drug product.
What is IIG in pharma?
FDA's Inactive Ingredient Guide (IIG) to obtain information on “acceptable levels” of excipients used in previously approved products.
Pharmaceutical Inactive Ingredients Example
Microcrystalline Cellulose, Propylene glycol, Starch, Mannitol, Silica, Talc, Aspartame, Lactose,Saccharin, Mg-Stearate etc.
Inactive Ingredient Database Guidance for Industry
FDA published a draft guidance on Inactive Ingredient Database in July, 2019 to give IID users a clearer understanding of the database’s benefits and limitations. It’s provides recommendations for how to use the IID in the development of drug products. The guidance also describes how the IID can be used in evaluating excipient safety, which can affect application filing and scientific review. In addition, this guidance discusses how the IID is structured; the data regarding excipients in the IID; and how nomenclature, maximum potency levels, and units of measure are presented in the IID.
IID Contents
- Ingredient Name: The ingredient name is the preferred term for the excipient as it appears in the Global Substance Registration System (GSRS).
- Route of Administration: The route of administration refers to the route of administration of the approved drugs in which the excipient was or is currently used that are the basis for the listing.
- Dosage Form: The dosage form of the excipient is the dosage form of the approved drugs in which the excipient was or is currently used that are the basis for the listing.
- Chemical Abstracts Service (CAS) Registry Number: The CAS Registry Number associated with the excipient is a recognized chemical identifier linked to chemical structure and other information associated with the excipient.
- Unique Ingredient Identifier (UNII): Assigned by GSRS, a UNII is a unique alphanumeric code that identifies a substance based on molecular structure and/or descriptive information. A UNII is displayed with excipients to facilitate Structured Product Labeling (SPL), which requires that a UNII be used for all ingredients, including excipients used in FDA-approved drugs.
- Maximum Potency: Maximum potency is the highest level of the excipient used in approved products. The IID lists the highest level per dosage unit of the excipient in each dosage form in which it is used. For topical products and other products where excipients are expressed as a percentage of the product formula, maximum potency is the highest formula percentage for products included in the IID.
IID Database
Difference between Maximum Potency and Maximum Daily Exposure (MDE)
Because there has been confusion over the years about the difference between maximum potency and MDE, an example is provided here to illustrate the difference. In a hypothetical case, where the maximum potency of an excipient is listed as 500 mg in the IID for the oral route of administration in oral capsules, if the maximum daily dose (MDD), the highest level of active ingredient dosed in a day (generally determined by following the instructions on the product labeling) is provided by two capsules per day, then the MDE would be 1,000 mg of the excipient. The MDE would not be reflected in the IID because the IID currently only shows the maximum potency (the maximum amount per dosage unit), which is 500 mg. Although the IID currently provides only the maximum potency per unit dose, it is important for applicants to consider the total daily exposure of excipients when developing new drug products