A process for the continuous solvent-free and mastication-free production of self-adhesive compositions based on polyisobutylene with at least one active pharmaceutical substance in a continuously operating apparatus having a filling section and a compounding section, comprising the following steps: a) feeding an initial batch comprising granulated polyisobutylene, at least one release auxiliary and at least one active pharmaceutical substance into the filling section of the apparatus;  if desired, feeding low molecular mass polyisobutylene, fillers, plasticizers, tackifiers and/or resins, b) transferring the feed components of the self-adhesive composition from the filling section to the compounding section, c) if desired, adding the components of the self-adhesive composition that have not been introduced in the filling section, such as low molecular mass polyisobutylene, fillers, plasticizers, tackifiers and/or resins, to the compounding section, d) if desired, adding further pharmaceutical substances to the compounding section of the apparatus, e) preparing a homogeneous self-adhesive composition in the compounding section, and f) discharging the self-adhesive composition.