Leachables

Leachables are chemical substances that migrate from packaging, device components, or manufacturing contact surfaces into a drug product or medical device under intended storage and use conditions. They can originate from polymers, elastomers, coatings, adhesives, metals, lubricants, and processing aids and may arise during storage, sterilization, or use.

Leachables are distinguished from extractables, which are the chemical species that could migrate under exaggerated extraction conditions. Extractables studies identify potential migrants, while leachables are the substances actually found in the product or its contact medium during use.

In pharmaceuticals and medical devices, leachables can affect product quality, safety, taste, odor, color, or biocompatibility. Regulatory frameworks require a risk-based assessment to identify, characterize, and control leachables using chemical characterization, toxicology, and compatibility data.

Characterization follows ISO 10993-18 and related guidance. Studies use simulants and real-time aging to release potential leachables, employing analytical techniques such as GC–MS, LC–MS, and ICP–MS (and non-targeted screens). Results are compared with toxicological thresholds to establish action levels.

Mitigation includes careful material selection, supplier declarations, change control, and design choices to minimize contact or use barrier layers. Cleaning, sterilization, and storage conditions are optimized to limit leaching. Ongoing surveillance and requalification help maintain acceptable leachable profiles.