Delivery of macromolecules through skin

High molecular weight therapeutic agents, i.e., polypeptides and proteins, are introduced as new drug entities. Currently, parenteral administrations are preferred for these molecules. Low membrane permeability and high enzyme acid susceptibility render these chemical entities unsuitable for oral administrations. However, frequent administrations of parenterals are uncomfortable to patients and need the assistance of medical personnel. At the same time, transdermal delivery of potential and promising drugs have created much interest in recent years in the pharmaceutical industry. This review gives an overview of the strategies adopted to deliver these challenging and promising macromolecules through the skin.