Low-Molecular Weight Amphiphiles

Low-molecular weight amphiphiles can self-assemble to form a variety of nanostructures, including micelles, vesicles and disk-shaped entities, depending on their geometry. These structures are stabilised by weak non-covalent forces and may be characterised with respect to their critical micellar concentration, aggregation number, size and morphology. Low-molecular weight amphiphiles may be applied as solubilisers in the formulation of hydrophobic drugs, as stabilisers in dispersed systems or as penetration enhancers. Their benefits must however be balanced against the risk of toxicity, including haemolytic activity. This chapter will provide an overview of the properties of low-molecular weight amphiphiles, including surfactants, bile salts and peptide amphiphiles as well as examples of their use in the formulation of nanomedicines.