Challenges in polysorbate characterization by mass spectrometry.

Polysorbates are used in a variety of applications over a wide range of markets. Simple in concept, these products are complex in actual composition. Mass spectrometry and related techniques have been effectively used to characterize these products, from the major components to the minor residual production byproducts and degradation species. In this paper we review the use of MALDI-MS, LC/MS, GC/MS, and SFC/MS in the analysis of these materials. The wealth of information provided by MALDI is presented, using Polysorbate 60 as an example. Limitations are described, with the impact of matrix selection and cationization agent demonstrated. Furthermore, unique challenges of MALDI analysis of Polysorbate 80 are shown. Polysorbates have been extensively analyzed, especially by the biopharmaceutical industry, to better understand the impact of various grades of purity and manufacture on the stability of formulations. Using Polysorbate 80 as an example, we illustrate some of the more advanced techniques used to more fully characterize these complex molecules using high-resolution LC/MS and LC/MS/MS. Finally, the use of other techniques (such as GC/MS and SFC/MS) is briefly reviewed.