Parenteral Delivery of Peptides and Proteins
INTRODUCTION Advancements in biotechnology have resulted in the synthesis of various biodrugs, that is, recombinant therapeutic peptides and proteins. These therapeutic agents are being used in the treatment of various diseases such as cancer, autoimmune, and metabolic disorders (1). The use of peptide and protein delivery for therapeutic purposes started a long time back. The development of smallpox vaccine by Edward Jenner is an example of successful protein delivery that was achieved in 1796 (2). Insulin was discovered by Frederick Banting and Charles Best in 1922 for the treatment of diabetes and marked the beginning of intensive research in the field of peptide and protein therapeutics and their delivery (2). Considerable efforts have been made since then to improve insulin formulations and modes of delivery for the treatment of diabetes mellitus (3). The pioneering work in the field of recombinant DNA technology was conducted in 1974 by Cohen and Boyer and the first recombinant DNA protein “human insulin” was introduced in 1982 by Genentech (2).