LC-ESI-MS Determination of Phospholipids and Lysophospholipids

Phospholipids are major constituents of biological membranes in plants and animals. Phospholipid-containing substances, such as lecithin, have also received increasing attention as emulsifiers in pharmaceutical drug delivery systems. The phospholipids phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, their lysophosphatidyl hydrolysis products and sphingomyelin, were quantified in lecithin and lecithin-containing drug-delivery emulsions. Lysophospholipids are constituents of lecithin, but their formation during thermal sterilization of the investigated drug delivery systems might contribute to the concentrations found in the emulsions.