Abstract: The invention concerns liquid or pasty thixotropic compositions containing an active substance for filling capsules at room temperature. The compositions become fluid by the effect of shearing when they pass through the filling nozzle, then recover their consistency with sufficient intensity and rapidity to prevent, after filling any leak between the two capsule parts. Said compositions are characterized in that their rheological properties are specially adapted for filling and for optimal recovery of consistency. They are preferably in the form of dispersions supporting amphiphilic excipients. Said compositions enable the formulation of active liquid, pasty and even solid substances.