Compositions, containing a ruthenium(III) complex and a heterocycle, methods for their manufacture, medicament containing these compositions and a kit.The invention relates to a composition (A), obtained by reacting a compound of the general formula (I) M.sub.3-n-p-2pr[RUX.sub.6-n-p-q-2rB.sub.n(H.sub.2O).sub.p(OH).sub.q(O).su- b.r].sub.2r+1 (I) with a compound of the general formula (II) B'(HX').sub.s (II). Furthermore, the invention relates to a composition (B), obtained by mixing a compound of the general formula (III) (B'H).sub.3-n-p-2pr[RUX.sub.6-n-p-q-2rB.sub.n(H.sub.2O).sub.p(OH).sub.q(O- ).sub.r].sub.2r+1 (III) with a compound of the general formula (IV) MX' (IV).