A method of forming a solid coating on microprojections in a microprojection array, comprising the steps of: (a) applying a liquid composition comprising one or more beneficial agents, a biocompatible carrier and a volatile liquid to the microprojections； (b) drying said liquid composition on said microprojections； (c) optionally, repeating steps (a) and (b) one or more times, to form said solid coating on said microprojections in the microprojection array, wherein the solid coating is adapted to allow release of the one or more beneficial agents from the coating upon hydration of the coating, and wherein said liquid composition has a beneficial agent concentration of from 1% to 30% by weight, and wherein the weight ratio of all biocompatible carriers to all beneficial agents ranges from 0.2:1 to 5:1. Also provided is a device for delivering a beneficial agent through the stratum corneum, comprising a plurality of microprojections and a solid coating obtainable by the method of the invention disposed upon at least a portion of the microprojections.
