BRIEFING

 Dipropylene Glycol. Because there is no existing NF monograph for this excipient, a new monograph based on the validated methods of analysis is proposed. The gas chromatographic procedures in the Assay are based on analyses performed with the Heliflex AT-Wax brand of column with G14, G15, G16, or G39 phase. The typical retention times for dipropylene glycol isomer 1, dipropylene glycol isomer 2, dipropylene glycol isomer 3, dipropylene glycol isomer 4, and dipropylene glycol isomer 5 are about 12.1, 12.9, 13.1, 13.4, and 14.2 min, respectively.

 (SE: D. Chavan)

 Case ID—SUB-568