Light Density Polyethylene (LDPE) bottles with a specific resin were chosen as container closure system (CCS) to fill “Latanoprost ophthalmic solution” (a generic drug product). As an alternative packaging component, additional manufacturer of LDPE bottles with the same characteristics as the previously selected LDPE bottles was chosen. The appropriateness of both packaging components was evaluated using an extractables and leachable (E&L) study and a formal stability programme that monitored quality of latanoprost ophthalmic solution. The results of relevant quality attributes in stability samples of latanoprost ophthalmic solution packed in both LDPE bottles were compared. It noticed that an unknown impurity in latanoprost ophthalmic solution packaged in LDPE bottles manufactured by an additional manufacturer. Further study revealed that this unknown impurity is Epsilon-caprolactam, a leachable of plastic used in the transportation of LDPE bottles. The leachability was validated through an extraction analysis of a plastic bag used for transportation. Thus, in certain cases, when the source of leachable is not identifiable by an E&L examination of primary, secondary, and tertiary packaging components, the assessment could be extended to include packaging components utilized throughout the supply chain.