US Patent 10238848 Solvent-cast microprotrusion arrays containing active ingredient

In an aspect of the invention, an array of microprotrusions is formed by providing a mold with cavities corresponding to the negative of the microprotrusions, casting atop the mold a first solution comprising a biocompatible material and a solvent, removing the solvent, casting a second solution atop the first cast solution, removing the solvent from the second solution, and demolding the resulting array from the mold. The first solution preferably contains an active ingredient.