• Leachables are compounds that migrate into a drug product from the container closure system (or process equipment) under normal condition. Both the primary container closure system in direct contact with the drug product (metered dose inhalers, prefilled syringes, eye dropper, IV bag, etc.) and the secondary CCS which does not the contact drug product (printed labels, boxes, foil pouches, etc.) can be sources of leachables. Leachables are the actual compounds that enter the drug product and present both a safety and an efficacy risk.

• Extractables are compounds that can be extracted from the container closure system (or process equipment) under exaggerated conditions that might become leachables. Extraction Studies are performed on CCS under exaggerated conditions with the goal of identifying all potential leachables. As shown below, under ideal situations leachables are a subset of the observed extractables. The observed extractables are used to develop analytical methods for leachables in the drug product.

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