The National Drug Code (NDC) is a system used to identify legend drugs. Part of the Drug Listing Act of 1972 requires manufacturers of drug products to assign a unique number to each product based on the individual drug type, strength, packaging size and where is was manufactured. For the purpose of studying for the PTCB or ExCPT exams, it is recommended to know what each segment of numbers identifies.
Every NDC number has 3 segments.
The First segment of an NDA number string identifies the drug's Manufacturer. This number is unique to the maker or re-packager of the product.
The Second segment of an NDA number string identifies the Product. This number is unique to the formulation and strength of the product.
The Third segment of an NDA number string identifies the Packaging. This number is unique to the size and quantity of the product.
When studying for the PTCB or ExCPT exam, you should learn which segment identifies what aspect of the product. If you are enrolled in a pharmacy technician program, the syllabus may expand on National Drug Code (NDC) numbers in more detail.