The microneedle is delivery device suitable for intradermal drug delivery and can deliver a variety of drugs and vaccines. In this study, we have studied vaccine and protein delivery for microneedle as the main themes. First, various adjuvants were investigated to improve the immunogenicity of the vaccine delivered by the microneedle. Secondly, we investigated suitable viscosity enhancers and stabilizers in order to coat botulinum toxin on PLLA microneedle. In addition, we conducted a study to confirm whether the microneedle was suitable for the ferret, a representative model of influenza research.