Abstract:
Follows decades of use as intravenous nutrition soybean oil emulsions (e.g., Intralipid) have become indicated in the treatment of drug toxicities by creating a pool of intravascular lipid microdroplets into which lipophilic intoxicants preferentially sequestered. As these emulsions were not specifically formulated for antidotal action more effective antidotes are sought. Recently, scavenging nanoparticles have emerged as detoxifying agents. Liposomes, spherical nanoparticles of phospholipid bilayer, have been widely used in medicine for drug delivery. Consideration of liposomes as agents of detoxification represents an about-face from this traditional use. Rather than active drug “loading” for the purpose of drug delivery, administration of “empty” liposomes in vivo aims to create an avid drug binding “sump”. The unique architecture of liposomes endows them with abilities to sequester drugs and metabolites with different properties by a number of mechanisms. Controlling the surface charge, or the length of phospholipid chain, can create more favorable conditions to sequester ionized or lipophilic drugs in the liposome surface or bilayer. The aqueous core of the liposome can be made chemically active such as by altering pH to allow amphiphilic weak acids or bases become charged and thus entrapped in the liposomal cores. Apart from sequestration in blood circulation via intravenous injection, liposomes also present an opportunity for extracorporeal removal of intoxicants. A technique using the lining of the abdominal cavity as a peritoneal dialysis membrane, peritoneal dialysis, can be augmented by liposomes thus promoting clearance of intoxicants. This chapter provides an overview of all state-of-the-art in this field.