USP Expands Extractables and Leachables Guidance with New Draft Chapters

The USP has expanded its Extractables and Leachables (E&Ls) chapter series <1664> by publishing three new draft chapters in Pharmacopoeial Forum 51(6). Comments are open until 31 January 2026. The updated series now includes: <1664.1> for orally inhaled and nasal products, <1664.2> for parenteral products, <1664.3> for topical ophthalmic products, and <1664.4> for topical and transdermal drug products.

Chapter <1664> addresses leachables originating from manufacturing equipment and container closure systems, with subsections focusing mainly on organic leachables. Inorganic leachables remain covered under the parent chapter. The revision of <1664.1> updates guidance for inhalation and nasal dosage forms and adds sections on elemental impurities, nitrosamines, and extended time-point testing.

New chapters <1664.3> and <1664.4> outline product-specific considerations for ophthalmic formulations and for topical/transdermal systems such as patches, creams, gels, sprays, and aerosols. Further details are available in the Pharmacopeial Forum.

17-11-2025