Provided is an organic solvent-free method for producing a plurality of microsphere having an average diameter of less than 500 μm in diameter and having average contact angle θc greater than 140°, consisting essentially of a biocompatible hot-melt carrier vehicle and a payload substance to be delivered, including melting and mixing a polymer carrier vehicle which is solid at room temperature and at least one payload substance, and dispensing microportions of the molten mixture through a droplet-forming space onto a cooled solid superoleophobic surface.
