Chiral Method Development Screening Techniques: A practical guide and new approaches in LC-MS

Retention mechanisms in chiral separations are complex and tend to be unpredictable. As a consequence, generic screening techniques utilizing many chiral stationary phases (CSPs) are typically used in method development practices. Normal phase chiral HPLC is commonly used in Drug Discovery and whilst such procedures are well established, there is a strong trend towards more sensitive detection by MS that now calls for a review of mobile phase selection.

Additionally, the development of chiral pharmaceuticals has matured, generating larger and larger numbers of chiral molecules in late-stage product development. As a result, chiral LC-MS methods for DMPK and aqueous-compatible/LC-MS friendly methods for pharmaceutical (drug substance) analysis have become even more important.

The key to successful chiral method development is the availability of simple, rapid and reliable screening protocols that avoid the possibility of false positives/negatives. This article outlines a set of simple protocols that uses one of the well-known classes of chiral stationary phases (CSPs), the macrocyclic glycopeptides. CHIROBIOTIC phases are highly compatible with LC-MS and operate in a variety of different mobile phase types. LC-MS can be used further in method development itself. HPLC combined with tandem MS is often used for the simultaneous quantification of parent drug and metabolites, but it also has the potential for even faster chiral method development. In this article, we also investigate simultaneous chiral method development, injecting a composite set of chiral molecules using LC-MS-MS. By comparing the results from the probe set with that from a single solute, the effect on the screening protocol of simultaneous screening is investigated.