A pharmaceutical composition comprising (a) a pharmaceutically acceptable gallium salt and (b) at least one administration agent selected from the following compounds of formula (1) and their pharmaceutically acceptable salts: 2-HO-Ar-C (O) -NR8-R7-COOH in which Ar is phenyl, optionally substituted with OH, halogen, C1-C4 alkyl, C2-C4 alkenyl, C1-C4 alkoxy or C1-C4 haloalkoxy; R7 is C4-C20 alkyl or C4-C20 alkenyl; R8 is hydrogen, C1-C4 alkyl, C2-C4 alkenyl, C1-C4 alkoxy, or C1-C4 haloalkoxy.Una composición farmacéutica que comprende (a) una sal de galio farmacéuticamente aceptable y (b) al menos un agente de administración seleccionado entre los siguientes compuestos de fórmula (1) y sus sales farmacéuticamente aceptables: 2-HO-Ar-C(O)-NR8-R7-COOH en la que Ar es fenilo, opcionalmente sustituido con OH, halógeno, alquilo C1-C4, alquenilo C2-C4, alcoxi C1-C4 o haloalcoxi C1- C4; R7 es alquilo C4-C20 o alquenilo C4-C20; R8 es hidrógeno, alquilo C1-C4, alquenilo C2-C4, alcoxi C1-C4, o haloalcoxi C1-C4.