Liposomes were the first nanoscale drug to be approved for clinical use in 1995. Since then, the technology has grown considerably, and pioneering recent work in liposome-based delivery systems has brought about remarkable developments with significant clinical implications. This includes long-circulating liposomes, stimuli-responsive liposomes, nebulized liposomes, elastic liposomes for topical, oral and transdermal delivery and covalent lipid-drug complexes for improved drug plasma membrane crossing and targeting to specific organelles. While the regulatory bodies' opinion on liposomes is well-documented, current guidance that address new delivery systems are not. This review describes, in depth, the current state-of-the-art of these new liposomal delivery systems and provides a critical overview of the current regulatory landscape surrounding commercialization efforts of higher-level complexity systems, the expected requirements and the hurdles faced by companies seeking to bring novel liposome-based systems for clinical use to market.
Keywords: Bioengineering; drug delivery; liposomes; regulatory landscape; synthetic biology.