In recent essays I have covered the “Anatomy of an NDC”, the “Anatomy of a GTIN” and the “Updated HDMA Bar Code Guidance: A Must Read“.  Now let’s put them all together.  Why would we need to do that?  Because the U.S. FDA requires many Over-The-Counter (OTC) and all prescription drugs marketed in the United States to have their National Drug Code (NDC) presented in the form of a linear barcode on the package.  Pure and simple.  To do that in a way that your trading partners can understand—that is, to do it interoperably—you need to follow a standard.  You have two realistic choices for standard approaches to this problem:  HIBCC or GS1.

The use of HIBCC standards is fairly common in the U.S. medical surgical devices supply chain but in the pharmaceutical supply chain it is very rare.  Most companies choose GS1’s barcode standards so that’s all I’m going to focus on in this essay.  If you want more information about how to do this with a HIBCC barcode find it here.

OVER-THE-COUNTER DRUGS:  GTIN-12

If your drug is sold over the counter (OTC), like aspirin and cold medications, the barcode on your packages will need to be scanned at point of sale (POS) terminals in the same way that any other consumer good is.  For that reason you need to put your National Drug Code (NDC) into a Universal Product Code (UPC) barcode in the United States.  A UPC-A barcode symbol contains a GS1 GTIN-12 data structure.  Here is what you need to do to convert your NDC into a GS1 GTIN-12:

1. Register your FDA Labeler Code with GS1 US who will convert it into a GS1 Company Prefix (GCP) and grant you the right to use it
   Recall from my previous essays that your FDA Labeler Code is either 4 or 5 digits long and a GCP can be anywhere from 6 to 10 digits depending on the fee you pay GS1 US when you register it.  In the case of FDA-regulated pharmaceuticals GS1 US will register a 4-digit FDA Labeler Code as a 6-digit GCP and a 5-digit FDA Labeler Code as a 7-digit GCP.  The reason is that they need to synchronize the length of the Item Reference portion of the resulting GTINs with the combined length of the Product Code and Package Size fields of your NDC.  This is to ensure that you are able to generate valid GTIN-based barcodes for every possible NDC that your Labeler Code enables you to generate.  You only need to register your FDA Labeler Code with GS1 US once as long as you keep up with the annual subscription fees so for subsequent drugs that use a Labeler Code that is already registered you can skip this step.  If you have multiple FDA Labeler Codes you need to register each one with GS1 US once.
   
   GS1 US has reserved GCPs that start with “03” for owners of FDA Labeler Codes as shown in the following table.

   

2. From your new GS1 Company Prefix construct your U.P.C. Company Prefix
   Ah ha!  This is an esoteric step.  It is necessary because of the way GS1 merged the formerly North American-only Uniform Code Council’s (UCC) Universal Product Code (UPC) company prefixes with the European Article Numbering Association’s (EAN) European Article Number (EAN) company prefixes and made the whole combined scheme suitable for global company prefixes and yet retained backward compatibility with the UPC and EAN.  But you don’t have to follow any of that.  Here’s what you do.
   
   You take the GCP that GS1 US assigned you and you strip off the leftmost digit.  That digit is always going to end up being a zero because we are dealing with an FDA regulated pharmaceutical and GS1 US will make sure that it is a zero on your behalf.  The remaining digits make up your new U.P.C. Company Prefix, usable only for generating UPC-A barcodes  and a few other less common things (see the GS1 General Specification for what else you can do with a U.P.C. Company Prefix).  For an NDC that has a 4-digit Labeler Code your U.P.C. Company Prefix will now start with a “3” and it will be 5 total digits long.  For an NDC that has a 5-digit Labeler Code your U.P.C. Company Prefix will now start with a “3” and it will be 6 total digits long as shown below.

   

3. Combine your U.P.C. Company Prefix with the Product Code and Package Size fields from your NDC
   For an NDC that has a 4-digit Labeler Code your Product Code and Package Size fields will be a total of 6 digits long.  Combine them with the GS1 U.P.C Company Prefix by placing them to the right of the prefix.  For an NDC that has a 5-digit Labeler Code your Product Code and Package Size fields will be a total of 5 digits long.  Combine them with the GS1 U.P.C. Company Prefix by placing them to the right of the prefix.  You should now have a total of 11 digits regardless of the length of your Labeler Code as shown in the table below.

   

4. Calculate the Check Digit and add it to complete your GTIN-12
   GS1 provides an algorithm to calculate the Check Digit in section 7.2.7 of the GS1 General Specification.  They also provide a handy calculator at this webpage(although where they say to enter the “Item Reference”, they really mean for you to enter the full prefix and item reference together).  Add check digit to the right of the code constructed in step 3.  You should now have a 12-digit code as shown below.  This is the GTIN-12 that can be encoded into a UPC-A barcode and printed on your product.

   

If you look closely at the table above you may see a short-cut that would get you directly to your GTIN-12.  All you need to do is take your 10-digit NDC and put a “3” in front of it and put a calculated check digit at the end as shown in the following table.

It is true that you can get there this way but then you might be tempted to skip step #1 and not obtain your official GCP.  As I understand it, since GS1 owns a copyright on the UPC family of barcode symbologies they could make a claim against your company if you encode your NDC into the copyrighted UPC-A symbology without first registering your FDA Labeler Code with them and paying whatever fee they place on that.  Talk to GS1 US to get the full story for your particular situation.  On the other hand, if you have already registered your Labeler Code with GS1 US then this short-cut should always produce your GTIN-12 for subsequent products that share the same FDA Labeler Code.

PRESCRIPTION DRUGS:  GTIN-14

Any drug distributed in the U.S. that is regulated by the FDA as a prescription drug must be dispensed by a registered pharmacist.  In that case it will not be scanned at a retail POS station.  For that reason you do not need to encode your NDC within a GTIN-12 but should encode it into a full GTIN-14.  GTIN-14s should also be used on all case labels whether OTC or prescription (see the HDMA Bar Code Guidance for details).  You can render a GS1 GTIN-14 identifier into a GS1-128, GS1 DataMatrix, or GS1 DataBar symbology depending on the application.

Here is what you need to do to properly convert your NDC into a GS1 GTIN-14 data structure:

1. Register your FDA Labeler Code with GS1 US who will convert it into a GS1 Company Prefix (GCP) and grant you the right to use it
   This is the same as step #1 for GTIN-12 above.
   
   
2. Combine your GS1 Company Prefix with the Product Code and Package Size fields from your NDC
   For an NDC that has a 4-digit Labeler Code your Product Code and Package Size fields will be a total of 6 digits long.  Combine them with the GS1 Company Prefix by placing them to the right of the prefix.  For an NDC that has a 5-digit Labeler Code your Product Code and Package Size fields will be a total of 5 digits long.  Combine them with the GS1 Company Prefix by placing them to the right of the prefix.
   
   
3. Add your Indicator Digit
   Next you need to add the single digit “Indicator digit” to the left of the GS1 Company Prefix.  Refer to my previous essay, “Anatomy of a GTIN” to learn what this digit is for.  For a unit of use package, use the value “0”.  You should now have a total of 13 digits regardless of the length of your Labeler Code.
   
   
4. Calculate the Check Digit and add it to complete your GTIN-14
   GS1 provides an algorithm to calculate the Check Digit in section 7.2.7 of the GS1 General Specification.  They also provide a handy calculator at this webpage.  Add check digit to the right of the code constructed in step 2.  You should now have a 14-digit code.  This is the GTIN-14 that can be encoded into a GS1 Code-128, GS1 DataMatrix, or DataBar barcode and printed on your product or case.  (NOTE:  DataBar should only be used on packages that are too small to accept one of the other symbologies.  See the HDMA Bar Code Guidelines for details.)

Finally, if you have already registered your Labeler Code with GS1 US you can use the following short-cut to construct your subsequent GTIN-14s.

The following figure summarizes the contents of all forms of the NDC for both GTIN-12 and GTIN-14 data structures.

IMPLICATIONS

There is an important implication stemming from the use of GS1 identifiers and barcodes to encode and render your NDC that I think needs to be explained.  This applies to any company that already possesses a GCP that does not match their FDA Labeler Code.  I can think of two ways that this might happen:

1. Any company in the U.S. that distributes non-drug products and already obtained a GCP from GS1 US for those products,
2. Any drug manufacturer that is based outside of the United States and that already possesses a GCP that was issued by their local, non-U.S. GS1 Member Organization.

Neither of these types of GCP’s can be used to encode an NDC for distribution within the U.S.  That’s because these GCPs do not match your FDA issued Labeler Code.  Only GS1 US, the U.S.-based GS1 Member Organization, can issue you a GCP that is properly based on your Labeler Code.  So these companies should contact GS1 US to register their Labeler Code, whether the company is based in the U.S. or not.

Systems and their associated databases should always be designed to accommodate the full GTIN-14 even when the application may seem to only need to deal with GTIN-12’s.  See GS1’s position paper on this topic for more explanation.

There are a few more “Anatomy of…” essays I want to write including the FDA’s Standardized Numeric Identifier (SNI), and GS-128 in the U.S. Pharma supply chain.  Watch for those essays in the near future.

Dirk.