How N-acyl amino acid surfactants adsorption at the air/water interface helps explaining “atypical” interaction with lipid membranes

N-acyl amino acids are promising anionic amphiphilic molecules, which consist of a linear aliphatic chain (hydrophobic tail) and an amino-acid residue (polar head). Although they have been mainly employed in cosmetics as detergents and foaming agents, these molecules seem to be also promising for pharmaceutical applications. Anionic amphiphiles, in fact, are used as excipients in pharmaceutical technology to improve solubilisation of poorly-water soluble drugs, to increase the wettability of solid dosage forms and/or to enhance drug penetration through biological membranes.Therefore, N-acyl amino acid surfactants could represent an alternative and safer option to sulfate-based anionic surfactants (e.g sodium dodecyl sulphate, SDS). Due to the lack of information regarding toxicity concerns of these surfactants, we performed a full characterization of their physicochemical properties.