Characterization of DSPE-mPEG raw materials from different vendors reveals differences in impurity profiles and polymer chain length polydispersity

PEGylated lipids such as 1,2-distearoyl-glycero-3-phosphatidylethanolamine-N-methoxy-polyethyleneglycol-2000 (DSPE-mPEG) are essential components of lipid nanoparticle formulations. They have an impact on the efficacy and quality of the drug products they used in, and as such should be carefully characterized. The present work used liquid chromatography with charged aerosol detection and high resolution mass spectrometry to investigate the polydispersity and purity of several lots of DSPE-mPEG, revealing significant differences in the level and identity of impurities. Additionally, mass spectral data showed that there were variations in the polyethylene glycol chain length between lots of comparable purity, which could not be detected by charged aerosol detection alone. The obtained results may be of importance in the development of new lipid nanoparticle based drugs. HighlightsO_LIImpurity identification of PEGylated lipid raw materials based on MS data C_LIO_LIDetermination of PEG polydispersity using high resolution mass spectrometry C_LIO_LIUse of CAD with inverse gradient for impurity quantification C_LI