BRIEFING

 Gamma-Aminobutyric Acid. Because there is no existing USP monograph for this dietary ingredient, a new monograph is being proposed. The liquid chromatographic procedure in the Assay and the test for Related Compounds is based on analyses performed with Waters XBridge Amide brand of column with L68 packing. The typical retention times for 2-pyrrolidinone, pyroglutamic acid, gamma-aminobutyric acid, and 4-(4-aminobutanoylamino)butanoic acid (GABA dimer) were approximately 4.5, 9.1, 18.7, and 23.6 min, respectively.

 (NBDS: B. Koshy)

 Case ID—SUB-1023