Lipid nanoparticles (LNPs) and liposomes are variations of lipid-based drug carriers differing in their internal structure. In liposomes, a phospholipid membrane encloses an aqueous inner cavity—a synthetic analog to natural cell walls. LNPs include nano-emulsions, micelles and solid lipid nanoparticles (SLN). Liposomes and LNPs serve as versatile drug delivery systems, offering control over composition, structure, and morphology, where these properties can be tailored to each specific pharmaceutical application.
Comprehensive characterization of the particles is essential for rapid and effective pharmaceutical product development as well as for regulatory approval. The basic properties to be evaluated are the size distribution and surface charge (zeta potential). In addition, knowledge of internal structure, mode of drug incorporation, drug loading capacity and drug release kinetics is of vital importance for the development of a successful drug delivery system.
