Reepmeyer John C, Brower James F, Ye Hongping
US Food and Drug Administration, Division of Pharmaceutical Analysis, St. Louis, MO 63101, USA.
J Chromatogr A. 2005 Aug 12;1083(1-2):42-51. doi: 10.1016/j.chroma.2005.05.092.
Equilin-3-sulfate and delta8,9-dehydroestrone-3-sulfate are two isomers found in equine conjugated estrogens that differ in structure only by the position of a double bond in the steroid B-ring. These geometric isomers were not resolved on a C18 column during the analysis of conjugated estrogen drug products by LC-MS using acetonitrile-ammonium acetate buffer as the mobile phase. While no separations of these two isomers were observed on C18 or other alkyl-bonded silica based phases using a variety of mobile phase conditions, partial separations were achieved on phenyl bonded silica phases with a resolution of 1.5 on a diphenyl phase, and baseline separations were readily achieved on two carbonaceous phases with resolutions routinely exceeding three on graphitic carbon-coated zirconia (Zr-CARB) and resolutions as high as 19 on porous graphitic carbon (Hypercarb). An examination of a selected few conjugated estrogens in the complex drug substance by LC-MS on Hypercarb is presented.
硫酸马萘雌酮-3和δ8,9-脱氢雌酮-3-硫酸盐是在马结合雌激素中发现的两种异构体，它们在结构上的差异仅在于甾体B环中双键的位置。在使用乙腈-醋酸铵缓冲液作为流动相通过LC-MS分析结合雌激素药物产品时，这两种几何异构体在C18柱上未得到分离。虽然在使用各种流动相条件的C18或其他烷基键合硅胶基固定相上未观察到这两种异构体的分离，但在苯基键合硅胶固定相上实现了部分分离，在二苯基固定相上的分离度为1.5，并且在两种含碳固定相上很容易实现基线分离，在石墨碳涂层氧化锆（Zr-CARB）上的分离度通常超过3，在多孔石墨碳（Hypercarb）上的分离度高达19。本文介绍了通过LC-MS在Hypercarb上对复合药物中选定的几种结合雌激素进行的检测。
