title: Transdermal Drug Delivery: Opportunities and Challenges for Controlled Delivery of Therapeutic Agents Using Nanocarriers.
abstract: BACKGROUND
  Transdermal drug delivery represents an extremely attractive and innovative route across the skin owing to the possibility for achieving systemic effect of drugs. The present scenario demands a special focus on developing safe medicine with minimized toxic adverse effects related to most of the pharmacologically active agents. Transdermal drug delivery would be a focal paradigm which provides patient convenience, first-pass hepatic metabolism avoidance, local targeting and reduction in toxic effect related to various categories of drugs like, analgesics, antiinflammatory, antibiotics, antiviral, anaesthetic, anticancer etc. Even this route has challenges due to highly organized structure of skin which acts as a main barrier to penetration of drug via the skin.
  
  
  METHODS
  Several alternative possible strategies are available which overcome these barriers, including use of penetration enhancer, eletroporation, iontophoresis and various nanotechnologically developed nanocarrier systems. The latest one includes employing liposome, dendrimers, nanoparticles, ethosome, carbon nanotube and many more to avoid associated limitations of conventional formulations. Numerous transdermal products such as Estrasorb, Diractin, VivaGel®, Daytrana®, Aczone, Sileryst® are available in the market having a novel strategy to achieve higher penetration of drugs. This encourages formulation fraternity to develop structurally deformable and stable nanocarriers as an alternative approach for controlled and reliable drug delivery across the skin barrier.
  
  
  CONCLUSIONS
  In this review, we will discuss nanocarriers mediated approaches that come-up with the solutions to the different challenges towards transdermal drug delivery, its clinical importance and latest insight to research in it.
  
  
  CONCLUSIONS
  The reports presented in this review confirm the wide application of nanocarriers for transdermal delivery of drug/gene.
authors.affiliation: Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, CG. India.
authors.forename: Balak Das
authors.initials: BD
authors.lastname: Kurmi
authors.affiliation: Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, CG. India.
authors.forename: Pawan
authors.initials: P
authors.lastname: Tekchandani
authors.affiliation: Columbia Institute of Pharmacy, Raipur, CG. India.
authors.forename: Rishi
authors.initials: R
authors.lastname: Paliwal
authors.affiliation: SLT Institute of Pharmaceutical Sciences, Guru GhasidasVishwavidyalaya (A Central University), Bilaspur, CG. India.
authors.forename: Shivani Rai
authors.initials: SR
authors.lastname: Paliwal
mesh_terms: D000287:Administration, Topical; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D006801:Humans; D049329:Nanostructures / Q000008:administration & dosage*; D012869:Skin Absorption
chemical_list: D003692:Delayed-Action Preparations
keywords: Transdermal; drug delivery; gene delivery; nanocarriers; penetration enhancers; targeting; vaccines