Fast evaporation aided coating of densely packed and short microprojection patches for enhanced vaccine delivery to the skin

We report a fast evaporation aided coating method to coat vaccines onto densely packed and very small microprojection containing patches which are used to efficiently deliver vaccines to the antigen presenting cells in the dermis/epidermis of the skin. Increased evaporation speed of coating solution aids localization of the vaccines on the distal tips of microprojections that penetrate into the skin; rather than to the backing and to the base of the microprojections. Therefore, the delivered efficiency of coated vaccine is increased. This method further improves the dose reduction effects we already observed with this novel patch design. This method of coating therefore will help to make more vaccine doses available in a case of a pandemic, help reduce the cost of the vaccines and provides a platform for future vaccines.