USP Proposes New NMR Method for Block Length Analysis of PLG/PLGA Polymers

The United States Pharmacopeia (USP) has issued a General Chapter Prospectus for a new chapter, <319> Nuclear Magnetic Resonance Spectroscopy Block Length Determination for Lactide-Glycolide Polymers. Released on 31 October 2025, the notice invites stakeholder comments until 30 November 2025, ahead of a planned proposal in Pharmacopeial Forum 52(2), expected in March–April 2026.

Lactide-glycolide (PLG) and lactic acid-glycolic acid (PLGA) polymers play an essential role as excipients in extended-release formulations and select medical devices. Their complex and variable structures, however, have limited the availability of consistent analytical techniques, often creating hurdles for manufacturers, particularly those developing generic products.

USP has already established chapters <315> and <316> to support polymer characterization using NMR for number-average molecular weight and SEC for molecular weight distribution. The proposed chapter <319> aims to expand this framework by introducing a standardized NMR method to measure block length, a key attribute influencing polymer performance.

14-11-2025