Iontophoresis-Mediated Transdermal Permeation of Peptide Dendrimers across Human Epidermis

Purpose of the Study: The overall aim of the present work was to elucidate the effects of iontophoresis on assisting permeation/deposition of peptide dendrimers across/within human skin. Procedures: A series of peptide dendrimers containing arginine and histidine as terminal acids were synthesized and characterized. These dendrimers were subjected to passive and iontophoretic permeation studies across human epidermis. Results: The synthesized peptide dendrimers were found to be stable in epidermal, dermal and skin extracts up to 6 h. Passive diffusion studies revealed that none of the synthesized peptide dendrimers permeated human epidermis up to 6 h, although minute concentrations of low molecular weight dendrimers were detected in receptor medium at the end of 24 h. Application of iontophoresis significantly increased the permeation of all the tested peptide dendrimers across human skin in a molecular weight-dependent manner compared to simple passive diffusion. Electromigration was found to be the dominant mechanism behind the iontophoretic permeation of peptide dendrimers across human skin. Conclusions: The present study demonstrates that iontophoresis is an effective technique in enhancing the transdermal permeation of peptide dendrimers. Message of the Paper: This study foresees the possibility of applying peptide dendrimers in iontophoretic delivery of drugs and macromolecules across/within the skin.