Modification of peptides and other drugs using lipoamino acids and sugars

The scientific literature is full of new small molecules and larger peptides identified as potential pharmaceutical agents for a variety of diseases. The majority of these compounds, however, will never progress into the clinic because of poor oral absorption and low metabolic stability. The development of practical, economic, and widely applicable systems to improve the bioavailability of drugs is a highly sought-after goal. The conjugation of a drug with lipid and/or sugar units represents one of the most important strategies being investigated in this new field of drug delivery. This chapter describes one method of introducing lipidic groups to drugs via lipoamino acids and also provides useful procedures for the efficient incorporation of sugar units into drugs, particularly peptide drugs, via solid phase synthesis.