Drugs

Inactive Ingredient Search for Approved Drug Products: Frequently Asked Questions

Application Update (8/12/2015): What’s new in the inactive ingredient database? We’ve revised some entries to display more accurate units. For some topical ingredients, the potency column now specifies whether potency is in percent weight to weight, weight to volume or volume to volume. These converted entries were verified for accuracy. Some liquid dosage forms were also similarly revised. We plan to update all entries for topical and liquid products in the near future. Additionally, preferred names were substituted for some ingredients for naming consistency. If an ingredient is not found in the IID, users are encouraged to check the Substance Registration System for the preferred name for the ingredient. The preferred name should then be used to search the IID.

About the Inactive Ingredient Database 

  1. What is an inactive ingredient?
  2. What is an active ingredient?
  3. What is the purpose of the Inactive Ingredient Database?
  4. How do you use the Inactive Ingredient Database?
  5. Can an inactive ingredient ever be considered an active ingredient?
  6. Does the Inactive Ingredient Database include contaminants found in approved drug products?
  7. What is a CAS Number?
  8. What is a UNII?
  9. How often do you update the Inactive Ingredient Database?
  10. How can I get a copy of the Inactive Ingredient Database?

 1. What is an inactive ingredient?

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.

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2. What is an active ingredient?

According to 21 CFR 210.3(b)(7), an active ingredient is any component of a drug product intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body of humans or other animals. Active ingredients include those components of the product that may undergo chemical change during the manufacture of the drug product and be present in the drug product in a modified form intended to furnish the specified activity or effect.

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3. What is the purpose of the Inactive Ingredient Database?

The Inactive Ingredient Database provides information on inactive ingredients present in FDA-approved drug products. This information can be used by industry as an aid in developing drug products. For new drug development purposes, once an inactive ingredient has appeared in an approved drug product for a particular route of administration, the inactive ingredient is not considered new and may require a less extensive review the next time it is included in a new drug product. For example, if a particular inactive ingredient has been approved in a certain dosage form at a certain potency, a sponsor could consider it safe for use in a similar manner for a similar type of product.

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4. How do you use the Inactive Ingredient Database?

You can search the Inactive Ingredient Database by entering any portion of the name of an inactive ingredient. You must enter at least three characters. Search results are displayed alphabetically, sorted first by ingredient, then by the route of administration and dosage form. Routes of administration and dosage forms are derived from current approved labeling.

Field Descriptions

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5. Can an inactive ingredient ever be considered an active ingredient?

The Inactive Ingredient Database contains inactive ingredients specifically intended as such by the manufacturer. Inactive ingredients can also be considered active ingredients under certain circumstances, according to the definition of an active ingredient given in 21 CFR 210.3(b)(7). Alcohol is a good example of an ingredient that may be considered either active or inactive depending on the product formulation.

Reactants in radiopharmaceutical kits, or inactive ingredients that physically or chemically combine with active ingredients to facilitate drug transport are considered inactive ingredients.

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6. Does the Inactive Ingredient Database include contaminants found in approved drug products?

No. The Inactive Ingredients Database does not include contaminants found in approved drug products.

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7. What is a CAS Number?

The acronym "CAS" stands for "Chemical Abstracts Service," a division of the American Chemical Society that provides comprehensive electronic chemical information services.  CAS assigns unique CAS Registry Numbers to chemical substances. Many inactive ingredients have CAS Registry Numbers, which are useful in searching other databases for chemical information. The CAS Registry Number itself has no chemical significance.

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8. What is a UNII?

The acronym “UNII” stands for “Unique Ingredient Identifier”. The UNII is a part of the joint United States Pharmacopeia (USP)/FDA Substance Registration System (SRS), which has been designed to support health information technology initiatives by providing unique identifiers for substances in drugs, biologics, foods, and devices based on molecular structure and/or descriptive information. The SRS is used to generate permanent, unique, unambiguous identifiers for substances in regulated products, such as ingredients in drug products. The UNII is being displayed in association with inactive ingredients to facilitate Structured Product Labeling (SPL), which requires that a UNII be used for all ingredients, including inactive ingredients.

Not all inactive ingredients will have a UNII. In order to receive a UNII, an ingredient must be a ‘substance’, which is defined as “Any physical material that has a discrete existence, irrespective of origin.” Products will not be assigned a UNII. For example, “purified water” and “sterile water for injection” are considered products within the context of the SRS because something is done to the substance “water” in order to make it more useful. Proprietary ingredients, such as “OPADRY II 85F10919 BLUE”, are considered products and will not be assigned a UNII. Such products are denoted by "N/A".

More information about the UNII and the SRS is available at Substance Registration System - Unique Ingredient Identifier (UNII). All chemically-related questions about the UNII or the SRS that are not answered on the FDA website should be directed fda-srs@fda.hhs.gov

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9. How often do you update the Inactive Ingredient Database?

We update the database quarterly, by the tenth working day of April, July, October, and January.

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10. How can I get a copy of the Inactive Ingredient Database?

You can download the contents of the Inactive Ingredient Database. The Inactive Ingredient Database Download are provided as delimited text and Excel files. 

Text files since 2009 are provided in order to track previous changes.

Data field descriptions
 

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Inactive Ingredient Database Help and Information files

Inactive Ingredients Database Help, Instruction, and Download files

Page Last Updated: 08/18/2015
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