Retainer for a microprotrusion member to impact applicator.

Assembly for use in a system of drug delivery stratum corneum piercing comprising: a microprotrusion member (44) with a plurality of microprojections piercing the stratum corneum and which is adapted to pierce the stratum corneum to improve the flow of transdermal agent; and a retaining device (34) connected releasably to said microprotrusion member (44) and which is adapted to join an impact device; wherein the microprotrusion member (44) has a central section containing said microprotrusions thereon, characterized in that an adhesive section surrounding the central section, a frangible section (62) surrounding the adhesive section and an outer portion (64) surrounding the frangible section (62) attached to the retainer (34).