Over time, chemical impurities can accumulate in the drug from degradation of formulation components, leaching from the container closure system, or entry from the local environment, which can include secondary packaging. The consequences to patients are uncertain but could include bronchospasm.
The draft guidance includes recommendations on appropriate protective secondary packaging; embossing and debossing of the primary container in lieu of paper labels; and the number of unit-dose containers to be contained within each protective secondary package. The guidance applies to drugs already on the market in the United States and to those under development.