Recent progress of micro-needle formulations: Fabrication strategies and delivery applications

Micro-needle (MN), a kind of micro-device, has been proposed to act as drug delivery systems since 1990s. It can be made from silicon, metal, polymer and ceramic materials. A broad range of biopharmaceuticals are delivered by MN into skin, especially the supra-molecule which can not get through the stratum corneum. MN causes less pain and increases drug absorption by orders of magnitude compared to hypodermic syringe. Several published articles in a decade have been reported, demonstrating a great progress in the design, manufacture and application of MN. This review spotlights the fabrication materials of MN, preparation methods and delivery applications of MN in human diseases. Potential safety aspects in this transdermal drug delivery systems are also described in detail.