USP Responds to Comments on Chapter <202> HPTLC Identification of Fixed Oils

In the recently published USP-NF 2026 Issue 1 Commentary (posted 25 July 2025), USP summarized stakeholder feedback and editorial decisions concerning General Chapter <202> Identification of Fixed Oils by Thin-Layer Chromatography. The procedure is used to identify fixed oils using high-performance thin-layer chromatography (HPTLC), with a suitable octadecylsilyl silica gel as the coating substance.

The revised draft had been made available in Pharmacopeial Forum PF 50(5), with the commenting period open until 30 November 2024.

One commenter requested clarification regarding the phrasing "Apply the Sample as narrow bands of 8-mm length…" and suggested modifying the description if bands are applied parallel to the plate's edge. In response, USP revised the method text to improve clarity.

A second comment suggested clearer instructions on how to apply the three available methods in the chapter. This suggestion was also accepted, and USP responded by adding the sentence: "If no method is specified in the monograph, then either of the methods can be applied".

For further information, please refer to the official USP–NF 2026 Issue 1 Commentary PDF file.