Background: The drug delivery of macromolecules such as proteins and peptides has become an important
area of research and represents the fastest expanding share of the market for human medicines. The most
common method for delivering macromolecules is parenterally. However parenteral administration of some
therapeutic macromolecules has not been effective because of their rapid clearance from the body. As a result,
most macromolecules are only therapeutically useful after multiple injections, which causes poor compliance and
systemic side effects.
Method: Therefore, there is a need to improve delivery of therapeutic macromolecules to enable non-invasive
delivery routes, less frequent dosing through controlled-release drug delivery, and improved drug targeting to
increase efficacy and reduce side effects.
Result: Non-invasive administration routes such as intranasal, pulmonary, transdermal, ocular and oral delivery
have been attempted intensively by formulating macromolecules into nanoparticulate carriers system such as
polymeric and lipidic nanoparticles.
Conclusion: This review discusses barriers to drug delivery and current formulation technologies to overcome the
unfavorable properties of macromolecules via non-invasive delivery (mainly intranasal, pulmonary, transdermal
oral and ocular) with a focus on nanoparticulate carrier systems. This review also provided a summary and discussion
of recent data on non-invasive delivery of macromolecules using nanoparticulate formulations.