Ophthalmic drug products (ODPs) present a special challenge for the measurement of extractables and leachables (E&L) due to the presence of multiple leachables sources. ODPs typically are packaged in labelled, semipermeable polymer (e.g., low density polyethylene) containers (i.e., primary container) and stored in cardboard containers (i.e., secondary container) along with instructions for use. The polymer, label, cardboard and paper are all possible sources of leachables.