A retainer is provided for holding a microprotrusion member for application of the microprotrusion member to the stratum corneum with an impact applicator. A basket andor a sieve may be carried in the processing chamber to facilitate drainage of spent processing water, and an apparatus may be included for removing neutralized waste through the opening in the processing chamber either by inverting the processor or by removing and inverting the basket andor sieve. The reaction medium includes an aqueous reaction solution and a substantially immiscible organic extraction solution. The power supply module has a module housing, which receives a battery and an introduction dome, formed integrally onto the module housing, for guiding the tool, on which dome there is an electrical interface with the electric power tool and at least one form-locking element for making a form lock with the tool housing is located.