Liposomal formulations for enhanced lymphatic drug delivery

The lymphatic system that extends throughout the whole body is one of useful targets for efficient drug delivery. The intestinal lymphatic drug delivery has been actively studied to date because administered drugs can avoid the first-pass metabolism in the liver, resulting in improvement of oral bioavailability. Drugs must be hydrophobic in order to be transported into the intestinal lymphatics because the lipid absorption mechanism in the intestine is involved in the lymphatic delivery. Therefore, various lipid-based drug carrier systems have been recently utilized to increase the transport of drug into the intestinal lymphatics. Lipidic molecules of the lipid-based drug delivery systems stimulate production of chylomicrons in the enterocytes, resulting in an increase in drug transport into lymphatic in the enterocytes. This review summarizes recently reported information on development of liposomal carriers for the intestinal lymphatic delivery and covers important determinants for successful lymphatic delivery.