BRIEFING

 Polypropylene Glycol 11 Stearyl Ether. This proposal is based on the version of the monograph official as of May 1, 2023. On the basis of comments and supporting data received, it is proposed to revise the Limit of Free Propylene Oxide test to introduce a more accurate and robust GC method based on analyses performed with the Agilent HP-PLOT U brand of column with G45 phase. This method can avoid interference in the chromatogram from another trace residue, 2-propanol. The typical retention times for propylene oxide and propionaldehyde are approximately 7.1 and 8.9 min, respectively.

 Additionally, minor editorial changes have been made to update the monograph to current USP style.

 (CE: P. Zhang)

 Case ID—SUB-845