Device for administering an active ingredient by oral mucosal route, comprising: - a bulb (1) containing a liquid, said ampoule having a single opening defining a peripheral peripheral edge (11) and closed by a lid (10) - a syringe body (2) provided with a dispensing orifice for dispensing said at least one active principle on the gingivo-jugal mucosa, - a piston (3) contained in said syringe body (2), - a stem piston (4) connected to said piston (3) for moving said piston in said syringe body (2), - a connector (20) formed integrally with or attached to said syringe body (2), said connector (20) ) being adapted to sealingly connect to said bulb (1), said connector (20) having an internal perforator (23) for perforating said lid (10) of said bulb (1) and connecting the interior of said bulb ( 1) with said syringe body (2), said internal perforator (23) forming said dispensing orifice of the syringe body (2) during the distribution of the active ingredient on said gingivo-jugal mucosa, said connector further comprising an outer protective skirt (21) surrounding said internal perforator (23), and said connector (20) having an annular receiving space (24) for receiving said peripheral axial edge (11) of said bulb (1), said annular receiving space (24) being defined between said internal perforator (23) and said outer protective skirt (21) . Dispositif d'administration d'un principe actif par voie per-muqueuse buccale, comportant: - une ampoule (1) contenant un liquide, ladite ampoule comportant une seule ouverture définissant un bord axial périphérique (11) et obturée par un opercule (10), - un corps de seringue (2) pourvue d'un orifice de distribution pour distribuer ledit au moins un principe actif sur les muqueuses gingivo-jugales, - un piston (3) contenu dans ledit corps de seringue (2), - une tige de piston (4) connectée audit piston (3) pour déplacer ledit piston dans ledit corps de seringue (2), - un connecte
