DSCSA “Serial Numbers”

????????????????I often write about the fact that drug manufacturers and repackagers that sell into the U.S. market must put “serial numbers”, or “serialize” their drug packages and homogeneous cases before November 27, 2017, but what exactly does that mean?

Let’s break it down.  The Drug Supply Chain Security Act (DSCSA) defines the term “Product identifier” this way:


The term ‘product identifier’ means a standardized graphic that includes, in both human-readable form and on a machine-readable data carrier that conforms to the standards developed by a widely recognized international standards development organization, the standardized numerical identifier, lot number, and expiration date of the product.”  (Section 581[14])

Back in March of 2010—3 ½ years before Congress passed the DSCSA—the FDA published final guidance called “Guidance for Industry, Standards for Securing the Drug Supply Chain – Standardized Numerical Identification for Prescription Drug Packages”, which defined the term “standardized numerical identifier (SNI)” this way:

The SNI for most prescription drug packages should be a serialized National Drug Code (sNDC). The sNDC is composed of the National Drug Code (NDC) (as set forth in 21 CFR Part 207) that corresponds to the specific drug product (including the particular package configuration) combined with a unique serial number, generated by the manufacturer or repackager for each individual package.  Serial numbers should be numeric (numbers) or alphanumeric (include letters and/or numbers) and should have no more than 20 characters (letters and/or numbers).”  (See “FDA Aligns with GS1 SGTIN For SNDC”.)

So the DSCSA product identifier is composed of:

  • the drug’s 10-digit NDC,
  • a unique serial number,
  • the lot number and
  • the expiration date of the product.

According to the SNI guidance, the “serial number” portion of the SNI should be up to 20 characters that can be letters and/or numbers.  (Notice that symbols are not allowed.)

So whenever people, including me, talk about “pharma serialization”, or “putting a serial number on a drug package”, or even a “serial number-based repository”, it’s all just shorthand for the DSCSA product identifier.  The serial number is actually just one part of that identifier, but people focus in on that part because that’s the part that is new and hard to implement correctly.  So please don’t get confused when you hear people using the terms “serial number” and “serialization” loosely.


Congress did not want the FDA to go off and create their own machine-readable data carrier, but they also did not want to prescribe exactly which existing standard should be used.  However, they described it in a way that there really is not any question about which standards development organization will be used:  the same widely recognized international standards development organization that is used to barcode drugs in the U.S. market today:  GS1.  From that, we can infer that the most common implementation of the DSCSA product identifier will be a GS1 Global Trade Identification Number (GTIN) (a GTIN-14 to be exact) that encodes an NDC (see “Depicting An NDC Within A GTIN”) combined with a serial number that conforms to the specification that Congress provided (above) in the format of a GS1 serial number element string that is associated with that GTIN.

The only difference I can see between the serial number specification that Congress provided and the specification of a GS1 serial number is that GS1 would allow some symbols to be used (see table 7.11 of the latest GS1 General Specification), but Congress does not.  That is not a big difference and is probably a good idea anyway.

In Section 582(a)(9) of the DSCSA, “PRODUCT IDENTIFIERS”, includes the requirement:

“…the applicable data—

“(i) shall be included in a 2-dimensional data matrix barcode when affixed to, or imprinted upon, a package; and

“(ii) shall be included in a linear or 2-dimensional data matrix barcode when affixed to, or imprinted upon, a homogeneous case…

This means that the “machine-readable data carrier” that carries the DSCSA product identifier must be a 2-dimensional “data matrix” (otherwise known as a “GS1 DataMatrix”, see “GS1 DataMatrix:  An Introduction and Implementation Guideline”) barcode.  That is pretty specific, although they really did not say it had to be the “GS1” version of the data matrix symbology.

Also be aware that the Healthcare Distribution Management Association’s (HDMA’s) “HDMA Guidelines for Bar Coding in the Pharmaceutical Supply Chain” (see “Updated HDMA Bar Code Guidance: A Must Read”), from back in 2011 (it is a little dated and I expect an updated version sometime this year) includes the following FAQ:

Q: Is there a preferred length (number of characters) for the serialized number which follows AI (21)?

“A: Yes, the preferred length is 12 digits (all numeric).  This allows the same serial number to be encoded in an SGTIN-96 RFID Tag.  This standard is limited to 12 digits and seems to be sufficient in length to allow for approximately 275 billion serial numbers.

They make a good point about the limitations of the early-model passive RFID tags—the 96-bit tags—that were around back then, but the DSCSA does not allow the use of RFID to carry the DSCSA product identifier so I don’t think I would worry about limiting yourselves to 12 digits or all numeric just for that purpose.  Of course, it is entirely possible (maybe likely, for the perennial optimists in the RFID industry) that the FDA will sanction the use of RFID tags to carry these identifiers in the future, but by then the 96-bit tags probably won’t even be available.  Even today, modern UHF passive RFID tags can accommodate the full 20 character alphanumeric set of characters that Congress allows.

For more details about GS1 serial numbers, see “Randomization—An Interview with Ken Traub—Part 1: GS1 Serial Number Considerations”.

And make sure you register for the LSPediA and Dirk Rodgers Consulting Webinar Series.  Riya Cao and I will cover the following three topics:

If you need help understanding the DSCSA, pick up a copy of “The Drug Supply Chain Security Act Explained“, by Dirk Rodgers.


2 thoughts on “DSCSA “Serial Numbers””

  1. Will these DSCSA “Serial Numbers” be applied to OTC products as well as Rx?

    1. Stephen,
      The DSCSA mandates serial numbers on Rx product only, and I do not think we will see anyone voluntarily applying them to OTC product. If anyone knows of an exception to that, let us know.


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