Such a potentially fatal error must be picked up by the pharmaceutical companies' incoming quality assurance department. The critical nature of this task puts a tremendous burden on the incoming inspection departments. Some are photocopies, laser prints, or color keys. If you add in thousands of SKU's and products, plus exporting in different languages, it becomes an almost impossible task. Tylenol, for example, has over 70 different SKU's alone.
Some companies go even further.
In addition to the Good Manufacturing Practices that drug companies must follow, Astra-Zeneca, has added a set of Military Standards for passing or failing inspection of an incoming lot of materials. Defects, for example on an insert with text and graphics, are divided into different critical levels for rejecting the entire lot of 150,000. Any one sample will reject the entire lot. The image is sent to a computer processor which creates an electronic negative. This is then used to subtract the incoming sample from the master.