Development of a drug-coated microneedle array and its application for transdermal delivery of interferon alpha.

Interferon alpha (IFNα) is one of the most famous drugs for the treatment of chronic hepatitis C and various types of human malignancy. Protein drugs, including IFNα, are generally administered by subcutaneous or intramuscular injection due to their poor permeability and low stability in the bloodstream or gastrointestinal tract. Therefore, in the present study, novel IFNα-coated polyvinyl alcohol-based microneedle arrays (IFNα-MNs) were fabricated for the transdermal delivery of IFNα without the painful injection. IFNα was rapidly released from MNs in phosphate buffered solution and these MNs presented piercing ability in the rat skin. Slight erythema and irritation were observed when MNs were applied to the rat skin, but these skin damages completely disappeared within 24 h after removing the IFNα-MNs. Furthermore, the pharmacokinetic parameters of IFNα-MNs were similar to those of IFNα subcutaneous administration. Finally, IFNα-MNs showed a significant antitumor effect in tumor bearing mice similar to that of IFNα subcutaneous administration. These results indicate that IFNα-MNs are a useful biomaterial tool for protein drug therapy and can improve the quality of life in patients by avoidance of painful injections.