There are two general classes of barcodes: one-dimensional (1D or linear) and two-dimensional (2D). They are used in different types of applications, and in some cases are scanned using different types of technology. The difference between 1D and 2D barcode scanning relies on the layout and amount of data that can be stored in each, but both can be used effectively in a variety of automatic identification applications.
1D Barcode Scanning:
Linear or 1D barcodes, like the UPC code commonly found on consumer goods, use a series of variable-width lines and spaces to encode data. Linear barcodes hold just a few dozen characters, and generally get physically longer as more data is added.
1D barcodes are dependent on database connectivity to be meaningful. If you scan a UPC code, for instance, the characters in the barcode have to relate to an item in a pricing database to be useful.
2D Barcode Scanning:
2D barcodes, like Data Matrix, QR Code or PDF417, use patterns of squares, hexagons, dots, and other shapes to encode data. They can be much smaller while holding more data (hundreds of characters) than 1D codes. Data is encoded based on both the vertical and horizontal arrangement of the pattern, thus it is read in two dimensions.
A 2D barcode doesn’t just encode alphanumeric information. These codes can also contain images, website addresses, voice, and other types of binary data. That means you can make use of the information whether you are connected to a database or not. A large amount of information can travel with an item labeled with a 2D barcode.
Applications for 1D and 2D Barcode Technology:
1D barcodes can be scanned with traditional laser scanners, or using camera-based imaging scanners. 2D barcodes, on the other hand, can only be read using imagers.
In addition to holding more information, 2D barcodes can be very small, which makes them useful for marking objects that would otherwise be impractical for 1D barcode labels. With laser etching and other permanent marking technologies, 2D barcodes have been used to track everything from delicate electronic printed circuit boards to surgical instruments.
1D barcodes, on the other hand, are well suited for identifying items that may be associated with other information that changes frequently. To continue with the UPC example, the item the UPC identifies will not change, although the price of that item frequently does; that’s why linking the static data (item number) to the dynamic data (the pricing database) is a better option than encoding price information in the barcode itself.
2D barcodes have increasingly been used in supply chain and manufacturing applications as the cost of imaging scanners has fallen. By switching to 2D barcodes, companies can encode more product data while making it easier to scan items as they move on assembly lines or conveyors — and it can be done without worrying about scanner alignment.
This is especially true in the electronics, pharmaceutical, and medical equipment industries where companies have been tasked with providing a large amount of product tracking information on some very small items. For example, the U.S. FDA’s UDI rules require several pieces of manufacturing information to be included on certain types of medical devices. That data could be easily encoded on very small 2D barcodes.
While there is a difference between 1D and 2D barcode scanning, both types are useful, low-cost methods of encoding data and tracking items. The kind of barcode (or combination of barcodes) you select will depend on the specific requirements of your application, including the type and amount of data you need to encode, the size of the asset/item, and how and where the code will be scanned.
Linear barcodes have served us well for almost half a century, but NOW is the time to move on to something else in the global pharmaceutical supply chain. I think most people already agree with that but I’m not sure everyone fully appreciates exactly why that is. It’s important to fully understand the reason why so that your resolution to move away from linear barcodes is strong and you won’t drag your feet or look back. So let me show you.
THE DAWN OF ^
No matter what you might think is going to happen to ePedigree or track & trace regulations going forward, more and more governments around the world are concluding that legitimate pharmaceuticals should come with unique identifiers—serial numbers—attached to them by the manufacturers and repackagers.
Serialization is upon us and I believe that in 10 years the ongoing benefits from it around the globe will significantly exceed the ongoing costs. Whether you agree to the benefits or not you certainly must accede to the fact that serialization in pharma supply chains is being mandated by more and more governments around the world, and that trend is not likely to reverse but will likely increase. Serialization mandates are currently in place for 2015-2016 in the state of California and they are under consideration by the two largest pharmaceutical markets in the world: The E.U. and the U.S.
Serialization is upon us and there is no turning back. While this is the foundation for why the industry must move away from linear barcodes, it is not the complete reason.
ADDING SERIAL NUMBERS TO PHARMACEUTICALS
Serialization mandates in countries around the world vary quite a bit but the more recent the regulation, the more likely they are to specify the use of GS1 standards, either as part of the mandate or as an example of one way to comply. GS1 linear barcodes are the most common type of product identifier barcode in use today in the larger markets so when you need to add a serial number to a drug, the addition of a GS1 serial number makes a lot of sense.
In a recent essay, “Depicting An NDC Within A GTIN”, I showed how to depict a U.S. Food and Drug Administration (FDA) National Drug Code (NDC) with an GS1 Global Trade Item Number (GTIN) for both over-the-counter (OTC) drugs and prescription drugs. Then, in my essay “Anatomy of an FDA SNI” I explained how to use GS1 standards to produce an FDA-compliant serialized NDC, or sNDC. An sNDC is what is necessary if you want to (voluntarily today) add a serial number to any drug that has an NDC assigned to it for the U.S. market according to the FDA’s Standardized Numeric Identifier (SNI) document from 2010 (see also my essay “FDA Aligns with GS1 SGTIN For SNDC“). At the end of my “Anatomy of an FDA SNI” essay I used the FDA’s own example (from their SNI Guidance document) to create the GS1 string of elements that would be encoded into a barcode and placed onto the drug package:
What I didn’t say in that essay is that you can’t encode this or any other sNDC in the GS1 Universal Product Code-A (UPC-A) barcode symbology that is used today for depicting NDC’s in linear barcodes on many of the pharmaceuticals in the U.S. supply chain. The UPC-A symbology itself does not support the addition of the serial number. For that you have to switch to another GS1 linear symbology known as GS1-128 (formerly known as UCC-128 and EAN-128).
Without the serial number, the linear UPC-A barcode for the NDC in the FDA’s example would look like this (all barcode images in this essay are courtesy of Terry Burton’s website):
That’s what the NDC barcode would look like today depicted as a GS1 GTIN-12 without the serial number. Here is what the full NDC and the serial number from the FDA’s example sNDC would look like depicted as a GTIN-14 plus serial number and rendered in the GS1-128 symbology:
Look at these two examples and you will see why serialization triggers the need to abandon linear barcodes. The linear barcodes that result after adding a serial number to NDCs are too long to fit onto most drug labels in a way that allows them to be scanned properly. Yes, this example uses U.S.-specific data and requirements but the same principles will apply to almost all countries and similar results will occur. Yes, the serial number in the FDA’s example is an extremely long one that probably exceeds the needs of 99% of companies, but the technology must accommodate the extremes or it is not usable.
And that’s not even the most extreme serial number I can think of. Serial number “YESTHISISAVALIDSRNUM” (yes, this is a valid serial number) is the most extreme serial number I can think of, and this is what it would look like as an sNDC in the GS1-128 symbology:
That’s even less workable.
SO WE NEED TO MOVE TO 2D BARCODES, RIGHT?
2-Dimensional barcode symbologies, like GS1’s DataMatrix, will solve this problem, yes. For example, here is what the previous two examples would look like encoded in GS1 DataMatrix:
Both of these symbols take up less space than the original UPC-A barcode that only contains the NDC. Even if we now add a lot/batch (AI=”10) and an expiration date (AI=”17) as I recommended in my essay “SNI’s Are Not Enough In a Plateau-Based Supply Chain Security Approach”, and we do so using the maximum lengths possible, these two become:
Whoa! What happened with the “extreme” example to make it blow up so big? There are two things that just happened. First, the DataMatix symbology is highly compressed and it automatically adjusts to accommodate the type and size of the data being encoded. Notice that the length of the lot number and the serial number in the two images above are the same, but the type of the data in the lot and serial numbers are not the same. When only digits are used the symbology can compress the image into a smaller space than it can when alphanumerics are used. In both examples I am using the maximum number of characters allowed, but in the extreme example I am using all alphas in both the serial number and in the lot number. That is the worst-case scenario and, as you can see, it takes up more space.
Second, the GS1 DataMatrix symbology will split into multiple segments (four in this case) once you cross a technical boundary related to the number of bits being encoded. Alphanumeric characters require more bits to encode them than numeric characters and in this example we crossed that boundary so the image generator split it into four segments. This helps readers decode larger symbols without significantly lowering reliability.
Considering the fact that it required me to come up with a pretty unrealistic extreme example of both serial number and lot number before the symbols made the leap to four segments I think it is unlikely that most drugs will require more than one segment. That’s because most drugs require many fewer than 20 characters for their lot/batch and serial numbers and most companies will probably stick with numeric-only characters in their serial numbers.
WHAT ABOUT RFID?
The pharma industry could move to Radio Frequency Identification (RFID) instead of 2D barcodes where regulations allow, but I believe that is unlikely except where the overseeing regulatory body actually requires it for all drugs in that jurisdiction. The explanation I documented for that in my essay “RFID is DEAD…at Unit-Level in Pharma” still applies. On the other hand, RFID would also solve the space problem that we have seen results with linear barcodes and the addition of serialization. In fact, most RFID tags would likely be placed under the product label so they would not take up any label real estate at all, but I don’t think manufacturers will view that savings as enough to offset the cost of the tags themselves.
THE TIME IS NOW
If you are a global pharma manufacturer or repackager and you haven’t yet figured out a plan for moving away from linear barcodes on your product labels, now is the time to start. Whether you choose 2D barcodes or RFID, the existence of serialization mandates around the world is the reason you need to take action and the time is now.
If you are a distributor, pharmacy or dispenser of pharmaceuticals in parts of the world where serialization has arrived or is coming, you need to develop a plan for reading the product codes and serial numbers using technologies that drug manufacturers and repackagers will move to. Now is the time to find out how many different technologies you will have to deal with. Now is the time to influence those manufacturers who are considering technologies that you don’t want and steer them toward those you do want.
Now is the time.
NOW IS THE TIME…EXCEPT FOR ONE THING!
Except, the FDA currently requires that drugs sold into the U.S. market be identified with their NDC specifically in a linear barcode. That means that in the U.S. today, you cannot move away from linear barcodes on your drug product, even when you need to add serial numbers to them for compliance with the California pedigree law in 2015-2017. As I show above, it doesn’t make sense to add serial numbers in linear barcodes so you are left with the probable decision to put the NDC and serial numbers in a 2D barcode or RFID tag in addition to the existing linear barcode that contains the NDC by itself. That’s pretty space inefficient.
The FDA is aware of this unfortunate situation as indicated by their recent request for comment on eliminating the requirement for the use of linear barcodes containing the NDC on drugs. Click here to read the responses they have collected so far. You have until February 23, 2012 to submit your own comments to the FDA through www.regulations.gov, docket number FDA-2011-N-0719.
Pay close attention to what the FDA does with this issue. More than likely it will impact everyone in the U.S. pharmaceutical supply chain.
Thank you to George Wright IV of PIPS for catching an embarrassing error in my construction of the GTIN-14’s encoded into the sample barcodes. I have now corrected and updated them.