Expert Q&A: What A Submission-Ready E&L Strategy Really Looks Like

Extractables and leachables remain a persistent source of regulatory risk, with recent FDA Complete Response Letters underscoring how often E&L gaps derail approvals. The challenge isn’t just testing — it’s understanding how materials, formulations, and lifecycle conditions interact to create risk. Factors such as extreme pH, organic solvents, single‑use systems, and high surface‑area packaging can all increase the likelihood of leachables, particularly for biologics and cell and gene therapies where even trace compounds may impact safety or performance.

Common missteps include starting E&L programs too late, relying on generic testing strategies, and failing to identify unknown compounds above safety thresholds. Regulators increasingly expect product‑specific, risk‑based approaches supported by robust analytical methods and defensible toxicological assessments.

This expert perspective offers practical guidance on building submission‑ready E&L packages, selecting appropriate technologies, and aligning studies with evolving standards such as USP <665>. Learn how earlier planning and deeper material understanding can reduce uncertainty, strengthen regulatory confidence, and keep development timelines on track.