BRIEFING

 〈318〉 Nuclear Magnetic Resonance Spectroscopy Monomer Ratio Determination for Lactide–Glycolide Polymers. On the basis of USP's validated methods of analysis, a new chapter is being proposed by the Excipient Test Methods Expert Committee (ETM EC).

 Lactide–glycolide and lactic acid–glycolic acid polymers are used extensively as excipients, including in complex extended-release drugs and medical devices. However, given the characterization and testing complexities of these polymers and the lack of standardized methods, their use in formulations and regulatory evaluation of drug products containing these polymers remains challenging.

 USP continues to seek solutions and provide both compendial standards and other emerging solutions for lactide–glycolide and lactic acid–glycolic acid polymers. USP standards include Stimuli articles, monographs, and general chapters.

 USP has introduced the NMR monomer ratio method to the first three lactide–glycolide polymer monographs: dl-Lactide and Glycolide (50:50) Copolymer 12000 Acid, dl-Lactide and Glycolide (50:50) Copolymer 12000 Ethyl Ester, and dl-Lactide and Glycolide (50:50) Copolymer 46000 Acid.

 USP is proposing to cover this NMR method in a general chapter for ease of reference in monographs and to broaden the applications of this method.

 As part of USP's stakeholder engagement model, on October 25, 2024, USP published a General Chapter Prospectus, which outlined the background for developing the chapter. No public comments were received on the prospectus.

 The current scope of this proposed chapter only covers analysis of lactide–glycolide polymers that are ring-opening copolymers of dl- or l-lactide and glycolide. USP will consider adding methods for other lactide–glycolide polymers and lactic acid–glycolic acid polymers in the future with supporting validation data.

 This chapter proposal contains the following method:

• Proton NMR Method for Monomer Ratio Determination for the lactide–glycolide polymer.

 Stakeholders are encouraged to contact USP to discuss any additional methods for characterization of lactide–glycolide and lactic acid–glycolic acid polymers.

 (ETM: P. Zhang)

 Case ID—SUB-1758