Each medication listed under Section 510 of the U.S. Federal Food, Drug, and Cosmetic Act is assigned a unique 10-digit, 3-segment number. This number, known as the National Drug Code (NDC), identifies the labeler or vendor, product, and trade package size.

• The first segment, the labeler code, is assigned by the Food and Drug Administration (FDA). A labeler is any firm that manufactures, repacks or distributes a drug product.
• The second segment, the product code, identifies a specific strength, dosage form, and formulation for a particular firm.
• The third segment, the package code identifies package sizes.

Both the product and package codes are assigned by the firm.

The NDC will be in one of the following configurations: 4-4-2, 5-3-2, or 5-4-1.

Each item is barcoded with a Universal Product Code that begins with a 3 (UPC-A) or 03 (EAN-13). The remainder of the numbers are the NDC number, plus the check digit.

An asterisk may appear in either a product code or a package code. It simply acts as a place holder and indicates the configuration of the NDC. Since the NDC is limited to 10 digits, a firm with a 5 digit labeler code must choose between a 3 digit product code and 2 digit package code, or a 4 digit product code and 1 digit package code.

Thus, you have either a 5-4-1 or a 5-3-2 configuration for the three segments of the NDC. Because of a conflict with the HIPAA standard of an 11 digit NDC, many programs will pad the product code or package code segments of the NDC with a leading zero instead of the asterisk.

Since a zero can be a valid digit in the NDC, this can lead to confusion when trying to reconstitute the NDC back to its FDA standard. Example: 12345-0678-09 (11 digits) could be 12345-678-09 or 12345-0678-9 depending on the firm's configuration. By storing the segments as character data and using the * as place holders we eliminate the confusion. In the example, FDA stores the segments as 12345-*678-09 for a 5-3-2 configuration or 12345-0678-*9 for a 5-4-1 configuration.

External links

• FDA National Drug Code Directory

pharmacology