Here's the overview.
Some outpatient prescriptions and most over the counter (OTC) medication package bar coding today use the 12 digit UPC-A bar code symbology. The OTC bar code may contain the NDC number or the Universal Product Code (UPC) number for the product.
Many outpatient medications that have the UPC number in the bar code also have a 10 digit National Drug Code number printed on the package (usually placed near the drug name) , in a 3 part format separated by dashes i.e xxx-yyy-zzz (where xxx=manufacturer, yyy=product, zzz=package size). A company called RxScan has created a database which crosswalks UPC-A bar codes and NDC numbers, enabling applications to be built which use bar codes to check drug safety.
Inpatient medications must contain the 10 digit NDC number embedded in the bar code itself per the FDA regulations specifying the bar code format .
The reason I was asked this question is that in FY09 we will implement electronic Medication Administration Records which depend on scanning a bar code on the unit of use package. In FY08, we set as a goal that at least 70% of drugs that we procure from vendors or which we repackage ourselves will have a bar-code on the unit-of-use drug package. During our mid-year physical inventory we took a snapshot and determined that over 90% of the unit-of-use packages we dispense have barcodes on them. 24% of these were RSS-stacked format, 8% were data matrix and 68% were single-line linear bar codes. However, we have not yet verified the readability or the content of those bar-codes, and we are not yet scanning all medications prior to administration to patients or upon filling automated dispensing cabinets (ADCs). We are barcoding certain high-risk medications upon filling ADCs in the NICU (e.g. heparin, digoxin, vitamin K) and hospital-wide for ADC-refrigerated, compounded narcotic-containing bags and syringes (for verification by RN upon removal from the ADC refrigerator because they can look alike).
Our efforts in FY09 will include documenting all the workflow redesign and new devices we need to deploy to support electronic Medication Administration Records. I'll document all these efforts on my blog!