Lab-Scale Flash Purification of Synthetic Lipid Facilitated by Evaporative Light Scattering Detection

Synthetic lipids and lipid nanoparticles (LNPs) have been used for mRNA-based drug administration for several years. The lipid mixtures typically contain four compounds, including cholesterol, a phospholipid, a PEGylated lipid, and a synthetic cationic lipid. This application note addresses the purification of a specific synthetic polar lipid, ALC-0315.

The synthesis of ALC-0315 is a multi-step process, also yielding several byproducts or impurities that require removal by normal phase flash chromatography. However, due to the
poor UV absorption by these lipids, their detection during chromatography is challenging. To address this issue and detect the synthetic lipids effectively, an evaporative light scattering detector (ELSD) was added into a Biotage®  Selekt Enkel flash chromatography system.

Experimental and Results

After various purification methods were tested, a heptane/ethyl acetate gradient and a Biotage®  Sfär KP-Amino column was found to provide a significant separation between
ALC-0315 and its synthetic byproducts. 

Chromatographic Conditions

For purification, Biotage® Selekt Enkel flash purification system together with Biotage®
 Selekt ELSD module was used with a 5-gram Biotage®  Sfär KP-Amino column.