MPA | Pharmacy News

By Kyle Busch, CPhT, manager of pharmacy call center, MeridianRx, Macomb

There are many settings in the pharmacy world. Whether you work in retail, inpatient, compounding, mail-order or the insurance side, there is one big similarity you likely you have in common with your peers: the amount of different numbers regarding medications you deal with on a daily basis.  Just to name a few, there are lot numbers, GCNs, NDCs and GPIs. All of these numbers are important in their own way. Some you may be familiar with while others you may have never heard of. But they are just numbers, right? Indeed they are just numbers, but there is so much value behind each of those numbers.

Lot Numbers serve a very important purpose in the pharmacy industry. They help us manage our inventory and maintain supply chain integrity. Did you know that about seven percent of the medications in the world are counterfeit? Utilizing Lot Numbers helps combat that problem. Lot Numbers also help narrow down which medications may be recalled or expired. Without Lot Numbers, all medications that carry the same name and strength would need to be pulled from the shelves making the medication unavailable to the public. This could cause extreme access to care issues for many patients. When you next reference a Lot Number, just think about its importance!

The next number relevant to a medication is the GCN or Generic Code Number. This number is set by First Data Bank (FDB) which is a drug pricing service. The GCN is unique to each medication’s formulation, strength and route of administration. For example, Omeprazole 20mg capsules will have a different GCN than Omeprazole 20mg tablets. One thing the GCN helps with is the specific pricing for each of the GCNs for a medication. A GCN number is not as flashy as the previous Lot Number, but still carries value.

The next number is by far the most common, the NDC or National Drug Code. This number is an 11-digit number. There is so much information that this number holds. There are three segments to an NDC. The first segment identifies the labeler of the medication. This segment typically references the first five digits to distinguish who makes the medication. The labeler code is assigned by the Food and Drug Administration. The second set of numbers helps identify the formulation of the medication, as well as the strength and what dosage form the medication is in (i.e., liquid, tablet, capsule, powder, etc.). The third and final segment is usually two digits. This segment identifies the package size for the medication. Both segments two and three are set by the labeler. Who knew 11 digits could mean so much?

The last number might be less common for some in the pharmacy field; however, it carries just as much significance. A medication’s GPI number or Generic Product Identifier is a hierarchical classification system that consists of 14 numbers. Every two numbers break down that specific medication starting with the drug group, all the way down to the specific strength. The first two digits identify the drug group like antihyperlipidemics. The next two digits help classify the drug class. For antihyperlipidemics, this would be HMG CoA Reductase Inhibitors. The subclass comes with the next two digits if there is one for the drug. If the drug does not have a subclass, it is usually represented with a double zero. The next two digits is the drug base name. In this ongoing example it would be Atorvastatin. Two digits later comes the drug name. This usually identifies more details about the medication. For antihyperlipidemics it would be Atorvastatin Calcium. The second from last two-digit sequence identifies the dosage form (i.e., tablets, capsules, cream, etc.). Finally, that last two digits help identify the strength. To learn more about GPI numbers, click here

All of these numbers each have their own unique importance. They help determine acquisition costs, reimbursement rates, track medications across the world and even code formularies for insurance plans. Sometimes we don’t think twice when we look at these numbers while performing our everyday responsibilities. Maybe next time we read that NDC over the phone or type it into a computer system we will realize the significance that number carries.


  1. Lowry Solutions. The Importance of Lot Track for Pharmaceutical Manufactures. Lowry Solutions website. Updated Sept. 18, 2014. Accessed September 2018.
  2. Pharmacy Healthcare Solutions, Inc. GPI vs. GSN. PHSIRx website. Accessed September 2018.
  3. Idaho Department of Health and Welfare. National Drug Code. IDMedicaid website. Updated Feb. 9, 2018. Accessed September 2018.

Bookmark and Share  

Search for
Pharmacy News