Manufacturers of pharmaceuticals must code the packaging of their products. The specifics of the code depend on national or other legislation but generally a lot code and a best before date are required.
Lasers are used to apply such codes because of their ability to mark paper and board, glass and the plastics typically used in packaging. They are an attractive alternative to inkjet (continuous and thermal) because they are clean, reliable and low cost.
Pharmaceutical manufacturers must also be able to recall their products if called upon to do so and code them to enable this to be possible. They must also supply local product information which can be extensive and laser is a practical way to be able to customize the packaging to this end.