s Recent Advances in Physical Approaches for Transdermal Penetration Enhancement

Transdermal delivery offers opportunities for inventive, challenging and valuable research with patient benefits. However, the prominent challenge in designing transdermal drug delivery systems is to overcome the natural transport barrier of the skin, the stratum corneum. Several physical and chemical enhancement techniques have been investigated in the last decade to breach the skin barrier and assist the transport of macromolecules across skin. Recent technological advances in this field include novel combination strategies of penetration enhancement techniques, microneedle array designs, needle-free technologies, nanocarriers, metered dose and microstructured transdermal systems. The present review reports on recent advances in physical approaches towards enhanced transdermal penetration. Enhancement strategies comprehensively covered in this review emphasize the significant achievements gained through successful transdermal delivery of hydrophilic macromolecules, vaccines, proteins, peptides, oligonucleotides, fluorescent dyes and plasmid delivery. Some commercially available technologies for transdermal delivery have also been covered. These novel technologies hold immense potential to advance further into clinical practice and enable better therapeutic applications and prophylactic interventions for various diseases.