title: Efficient method development strategy for challenging separation of pharmaceutical molecules using advanced chromatographic technologies.
abstract: In this paper, we describe a strategy that can be used to efficiently develop a high-performance liquid chromatography (HPLC) separation of challenging pharmaceutical molecules. This strategy involves use of advanced chromatographic technologies, such as a computer-assisted chromatographic method development tool (ChromSword) and an automated column switching system (LC Spiderling). This process significantly enhances the probability of achieving adequate separations and can be a large time saver for bench analytical scientists. In our study, the ChromSword was used for mobile phase screening and separation optimization, and the LC Spiderling was used to identify the most appropriate HPLC columns. For proof of concept, the analytes employed in this study are the structural epimers betamethylepoxide and alphamethylepoxide (also known as 16-beta methyl epoxide and 16-alpha methyl epoxide). Both of these compounds are used in the synthesis of various active pharmaceutical ingredients that are part of the steroid pharmaceutical products. While these molecules are relatively large in size and contain various polar functional groups and non-polar cyclic carbon chains, their structures differ only in the orientation of one methyl group. To our knowledge, there is no reported HPLC separation of these two molecules. A simple gradient method was quickly developed on a 5 cm YMC Hydrosphere C(18) column that separated betamethylepoxide and alphamethylepoxide in 10 min with a resolution factor of 3.0. This high resolution provided a true baseline separation even when the concentration ratio between these two epimers was 10,000:1. Although outside of the scope of this paper, stability-indicating assay and impurity profile methods for betamethylepoxide and for alphamethylepoxide have also been developed by our group based on a similar method development strategy.
authors.affiliation: Global Quality Services - Analytical Sciences, Schering-Plough Corporation, Union, NJ 07083, USA.
authors.forename: Kang Ping
authors.initials: KP
authors.lastname: Xiao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xiong
authors.forename: Fang Zhu
authors.initials: FZ
authors.lastname: Liu
authors.forename: Abu M
authors.initials: AM
authors.lastname: Rustum
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004852:Epoxy Compounds / Q000737:chemistry*; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D015203:Reproducibility of Results; D013237:Stereoisomerism
chemical_list: D004852:Epoxy Compounds; D004364:Pharmaceutical Preparations