Used extensively in lipid nanoparticle (LNP) formulations for drug delivery, particularly in mRNA-based therapeutics and vaccines. The PEGylated phospholipid enhances nanoparticle stability by reducing aggregation and prolonging circulation time in the bloodstream. It acts as a stealth coating, minimizing recognition by the immune system and preventing rapid clearance. This enables targeted delivery of encapsulated drugs, especially in cancer therapies and genetic medicines. Its role is critical in formulations like those used in COVID-19 mRNA vaccines, where it supports the integrity and efficacy of the delivery system.